The Application Connector (AC) is a proprietary Kyma implementation that allows you to connect with external solutions. No matter if you want to integrate an on-premise or a cloud system, the integration process doesn't change, which allows to avoid any configuration or network-related problems.

The external solution you connect to Kyma using the AC is represented as an Application (App). There is always a one-to-one relationship between a connected solution and an App, which helps to ensure the highest level of security and separation. This means that you must create five separate Apps in your cluster to connect five different external solutions and use their APIs and Event catalogs in Kyma.

The AC gives you this functionality:

• Manages the lifecycle of Apps.
• Establishes a secure connection and generates the client certificate used by the connected external solution.
• Registers the APIs and the Event catalogs of the connected external solution.
• Delivers the Events from the connected external solution to the Kyma Event Bus.
• Proxies calls sent from Kyma to external APIs registered by the connected external solution.
• Allows to map an App to a Kyma Namespace and use its registered APIs and Event catalogs in the context of that Namespace.
• Integrates the registered APIs and Event catalogs with the Kyma Service Catalog.

All of the AC components scale independently, which allows to adjust it to fit the needs of the implementation built using Kyma.

Supported APIs

The Application Connector allows you to register secured REST APIs exposed by the connected external solution. The Application Connector supports a variety of authentication methods to ensure smooth integration with a wide range of APIs.

You can register an API secured with one of the following authentication methods:

• Basic Authentication
• OAuth
• Client Certificates

NOTE: You can register non-secured APIs for testing purposes, however, it is not recommended in the production environment.

In addition to authentication methods, the Application Connector supports Cross-Site Request Forgery Tokens.

You can register any API that adheres to the REST principles and is available over the HTTP protocol. The Application Connector also allows you to register APIs implemented with the OData technology.

You can provide specifications that document your APIs. The Application Connector supports AsyncAPI, OpenAPI, and OData specification formats.

TIP: Follow this link to read about the CMS AsyncAPI Service used in Kyma to process AsyncAPI specifications.

The Connector Service generates client certificates which are used to secure the communication between Kyma and the connected external solutions.

Generating a new client certificate is the first step in the process of configuring an Application (App). Kyma stores the root certificate and serves as the Certificate Authority when you configure a new App. When you generate a new client certificate, the Connector Service returns it along with the root certificate to allow validation.

This diagram illustrates the client certificate generation flow in details:

1. The administrator requests for a token using the CLI or the UI and receives a link with the token, which is valid for a limited period of time.
2. The administrator passes the token to the external system, which requests for information regarding the Kyma installation. In the response, it receives the following information:
   • the URL to which a third-party solution sends its Certificate Signing Request (CSR)
   • the URL of the metadata endpoint
   • information required to generate a CSR
3. The external system generates a CSR based on the information provided by Kyma and sends the CSR to the designated URL. In the response, the external system receives a signed certificate. It can use the certificate to authenticate and safely communicate with Kyma.
4. The external system calls the metadata endpoint that contains the following information:
   • the URL of the Application Registry API
   • the URL of the Event Service API
   • the certificate renewal URL used to rotate certificates
   • the certificate revocation URL used to revoke compromised certificates
   • information uniquely identifying certificate, such as the Application name
   • information required to generate a CSR

NOTE: The external application should not hardcode any URLs. The information returned from the metadata endpoint should be stored by the external application along with the certificate. This approach implicates less coupling and offers a great deal of flexibility.

NOTE: The external application can call the metadata endpoint to fetch information required to generate a CSR prior to certificate renewal. This approach makes certificate rotation process convenient and flexible, since the external application does not need to store information required to generate a CSR in its data model.

NOTE: Follow this tutorial to learn how to get a client certificate for your implementation.

The Application Gateway sends the requests from Lambda functions and services in Kyma to external APIs registered with the Application Registry. The Application Gateway works in conjunction with the Access Service, which exposes the Application Gateway.

NOTE: The system creates an Access Service for every external API registered by the Application Registry.

The following diagram illustrates how the Application Gateway interacts with other components and external APIs which are either unsecured or secured with various security mechanisms and protected against cross-site request forgery (CSRF) attacks.

1. A lambda function calls the Access Service. The name of every Access Service follows this format: {application-name}-{service-id}
2. The Access Service exposes the Application Gateway.
3. The Application Gateway extracts the Application name and the service ID from the name of the Access Service name. Using the extracted Application name, the Application Gateway finds the respective Application custom resource and obtains the information about the registered external API, such as the API URL and security credentials.
4. The Application Gateway gets a token from the OAuth server.
5. The Application Gateway gets a CSRF token from the endpoint exposed by the upstream service. This step is optional and is valid only for the API which was registered with a CSRF token turned on.
6. The Application Gateway calls the target API.

Caching

To ensure optimal performance, the Application Gateway caches the OAuth tokens and CSRF tokens it obtains. If the service doesn't find valid tokens for the call it makes, it gets new tokens from the OAuth server and the CSRF token endpoint. Additionally, the service caches ReverseProxy objects used to proxy the requests to the underlying URL.

Handling of headers

The Application Gateway removes the following headers while making calls to the registered applications:

• X-Forwarded-Proto
• X-Forwarded-For
• X-Forwarded-Host
• X-Forwarded-Client-Cert

In addition, the User-Agent header is set to an empty value not specified in the call, which prevents from setting the default value.

The Application Broker (AB) workflow consists of the following steps:

1. The Application Broker watches for Applications (Apps) in the cluster and ApplicationMappings (AMs) in all Namespaces.
2. The user creates an ApplicationMapping custom resource in a given Namespace. The AM activates services offered by an App. The AM must have the same name as the App.
3. The Application Broker creates an application-broker Service Broker (SB) inside the Namespace in which the AM is created. This Service Broker contains data of all services provided by the activated Applications. There is always only one application-broker Service Broker per Namespace, even if there are more AMs.
4. The Service Catalog fetches services that the application-broker Service Broker exposes.
5. The Service Catalog creates a ServiceClass for each service received from the Service Broker.

When this process is complete, you can provision and bind your services.

Provisioning and binding for an API ServiceClass

This ServiceClass has a bindable parameter set to true which means that you have to provision a ServiceInstance and bind it to the service or lambda to connect to the given API. The provisioning and binding workflow for an API ServiceClass consists of the following steps:

1. Select an API ServiceClass from the Service Catalog.
2. Provision this ServiceClass by creating its ServiceInstance in a Namespace.
3. Bind your ServiceInstance to the service or lambda. During the binding process, ServiceBinding and ServiceBindingUsage resources are created.

• ServiceBinding contains a Secret with a GatewayURL required to connect to the given API.
• ServiceBindingUsage injects the Secret, together with the label given during the registration process, to the lambda or service.

4. The service or lambda calls the API through the Application Connector. The Application Connector verifies the label to check if you have the authorization to access this API.
5. After verifying the label, the Application Connector allows you to access the Application API.

Provisioning and binding for an Event ServiceClass

This ServiceClass has a bindable parameter set to false which means that after provisioning a ServiceClass in the Namespace, given Events are ready to use for all services. The provisioning workflow for an Event ServiceClass consists of the following steps:

1. Select a given Event ServiceClass from the Service Catalog.
2. Provision this ServiceClass by creating a ServiceInstance in the given Namespace.
3. During the provisioning process, the EventActivation resource is created together with the ServiceInstance. EventActivation allows you to create an Event Bus Subscription.
4. A Subscription is a custom resource by which an Event Bus triggers the lambda for a particular type of Event in this step.
5. The Application sends an Event to the Application Connector.
6. The Application Connector sends an Event to the lambda through the Event Bus.

Provisioning and binding for both the API and Event ServiceClass

This ServiceClass has a bindable parameter set to true. The provisioning and binding workflow for both the API and Event ServiceClass is a combination of steps described for an API ServiceClass and an Event ServiceClass.

To access the Application Connector on a local deployment of Kyma, you must add the Kyma server certificate to the trusted certificate storage of your programming environment. This is necessary to connect the external solution to your local Kyma deployment, allow client certificate exchange, and API registration.

For example, to access the Application Connector from a Java environment, run this command to add the Kyma server certificate to the Java Keystore:

sudo {JAVA_HOME}/bin/keytool -import -alias “Kyma” -keystore {JAVA_HOME}/jre/lib/security/cacerts -file {KYMA_HOME}/installation/certs/workspace/raw/server.crt

To consume an external solution connected to Kyma, you must register it as an Application (App). As a result of registering the external solution, ClusterServiceClasses are created in the Service Catalog.

External solution's services in the Service Catalog

The Example API is registered in Kyma with the targetUrl pointing to https://www.orders.com/v1/orders. The ID assigned to the API in the registration process is 01a702b8-e302-4e62-b678-8d361b627e49.

The Application Broker, which provides ServiceClasses to the Service Catalog, follows this naming convention for its objects:

{application-name}-{service-id}

The {service-id} is the service identifier assigned in the process of registration. The {application} is the name of the App created in Kyma. It represents an instance of the connected external solution that owns the registered service. Such identifier used by the Application Broker is referred to as the name of a ClusterServiceClass in the Service Catalog.

This an example of a full ClusterServiceClass name:

re-ec-default-01a702b8-e302-4e62-b678-8d361b627e49

Service consumption

After you provision the Example API in the Namespace of your choice using the Service Catalog, you can bind it to your application and consume it by calling the URL you get as a result of a successful binding.

This is a sample URL for the Example API:

re-ec-default-01a702b8-e302-4e62-b678-8d361b627e49.kyma-integration/orders

When you call this URL, the Application Gateway passes all requests to the https://www.orders.com/v1/orders address, which is the targetUrl registered for the Example API. You do not have to get an OAuth token and manually include it in the call as the Application Gateway does it for you automatically.

The Application Registry allows you to register the APIs and Event catalogs of the services exposed by the connected external solution.

The Application Registry stores the data of all registered services in:

• Application custom resource (CR), which stores the metadata of the service.
• DocsTopic custom resource (CR), which stores the links to API specification, Event catalog, and documentation.
• Upload Service, which stores the files containing API specification, Event catalog, and documentation in an Asset Store bucket.
• Kubernetes secrets, which stores sensitive data, such as OAuth credentials.

Kubernetes APIs interaction

The Application Registry interacts with Kubernetes APIs to perform these tasks:

• Modify the Application CR instance.
• Create Secrets which contain client ID and client secret used to access OAuth-secured APIs.
• Create the Access Service.

The Application Connector supports passing the access token directly in the request.

Passing the access token

If the user is already authenticated to the target API, the access token can be passed in a custom Access-token header. The value of the header is of the Bearer {token} or Basic {token} form. If the Application Connector detects that the custom header is present, instead of performing authentication steps, it removes the Access-token header, and passes the received value in the Authorization header.

The Application Registry supports the following formats of the API specification:

• OpenAPI 2.0
• OData XML 2.0, 3.0 and 4.0

You can pass the API specification in two ways:

• JSON format
• SpecificationUrl

NOTE: Specification passed directly as a JSON has a higher priority than SpecificationUrl. If you use these two methods at once, SpecificationUrl is ignored.

For the OpenAPI format, both methods are supported. You can register OData APIs only with SpecificationUrl.

The Application Connector is secured with a client certificate verified by the Istio Ingress Gateway.

The Certificates are generated and stored as Kubernetes Secrets by the Application Connector Certs Setup job.

By default, the server key and certificate are automatically generated. You can provide a custom server certificate and key during the installation by setting them as the following overrides:

global.applicationConnectorCaKey: {BASE64_ENCODED_PRIVATE_KEY}
global.applicationConnectorCa: {BASE64_ENCODED_CERTIFICATE}

NOTE: To use a custom certificate and key, you must provide both values through overrides. If either the certificate or key is incorrect or isn't provided, a new certificate and key pair is generated.

This is a sample ConfigMap that contains overrides with a custom certificate and key:

apiVersion: v1
kind: ConfigMap
metadata:
  name: application-connector-certificate-overrides
  namespace: kyma-installer
  labels:
    installer: overrides
    kyma-project.io/installation: ""
data:
  global.applicationConnectorCa: "{BASE64_ENCODED_CERTIFICATE}"
  global.applicationConnectorCaKey: "{BASE64_ENCODED_PRIVATE_KEY}"

TIP: To learn more about how to use overrides in Kyma, see the following documents:

• Helm overrides for Kyma installation

To configure the Application Registry sub-chart, override the default values of its values.yaml file. This document describes parameters that you can configure.

TIP: To learn more about how to use overrides in Kyma, see the following documents:

• Helm overrides for Kyma installation
• Sub-charts overrides

Configurable parameters

This table lists the configurable parameters, their descriptions, and default values:

To configure the Connectivity Certs Controller sub-chart, override the default values of its values.yaml file. This document describes parameters that you can configure.

TIP: To learn more about how to use overrides in Kyma, see the following documents:

• Helm overrides for Kyma installation
• Sub-charts overrides

Configurable parameters

This table lists the configurable parameters, their descriptions, and default values:

To configure the Connector Service sub-chart, override the default values of its values.yaml file. This document describes parameters that you can configure.

TIP: To learn more about how to use overrides in Kyma, see the following documents:

• Helm overrides for Kyma installation
• Sub-charts overrides

Configurable parameters

This table lists the configurable parameters, their descriptions, and default values:

To configure the Application Connectivity Certs Setup Job, override the default values of its values.yaml file. This document describes parameters that you can configure.

TIP: To learn more about how to use overrides in Kyma, see the following documents:

• Helm overrides for Kyma installation
• Sub-charts overrides

Configurable parameters

This table lists the configurable parameters, their descriptions, and default values:

The applicationmappings.application.kyma-project.io CustomResourceDefinition (CRD) is a detailed description of the kind of data and the format used to enable APIs and Events from an Application (App) as a ServiceClass in a given Namespace. To get the up-to-date CRD and show the output in the yaml format, run this command:

kubectl get crd applicationmappings.applicationconnector.kyma-project.io -o yaml

Sample custom resource

This is a sample ApplicationMapping resource which enables the test Application in the production Namespace. In this example, all services provided by the Application are enabled:

apiVersion: applicationconnector.kyma-project.io/v1alpha1
kind: ApplicationMapping
metadata:
  name: test
  namespace: production

Using ApplicationMapping, you can also enable only the selected services in a given Namespace. See the example:

apiVersion: applicationconnector.kyma-project.io/v1alpha1
kind: ApplicationMapping
metadata:
  name: test
  namespace: production
spec:
  services:
    - id: ac031e8c-9aa4-4cb7-8999-0d358726ffaa
    - id: bef3143c-d1a5-674c-8dc9-ab4788896fba

The services list contains IDs of enabled services.

Custom resource parameters

This table lists all the possible parameters of a given resource together with their descriptions:

Related resources and components

These components use this CR:

The eventactivations.applicationconnector.kyma-project.io CustomResourceDefinition (CRD) is a detailed description of the kind of data and the format used to create an Event Bus Subscription and to get an Event schema. To get the up-to-date CRD and show the output in the yaml format, run this command:

kubectl get crd eventactivations.applicationconnector.kyma-project.io -o yaml

Sample custom resource

This is a sample resource that allows you to consume Events sent from the service with the ac031e8c-9aa4-4cb7-8999-0d358726ffaa ID in a production Namespace.

apiVersion: applicationconnector.kyma-project.io/v1alpha1
kind: EventActivation
metadata:
  name: "ac031e8c-9aa4-4cb7-8999-0d358726ffaa"
  namespace: production
spec:
  displayName: "Orders"
  sourceId: "prod"

Custom resource parameters

This table lists all the possible parameters of a given resource together with their descriptions:

Related resources and components

These are the resources related to this CR:

These components use this CR:

The tokenrequests.applicationconnector.kyma-project.io CustomResourceDefinition (CRD) is a detailed description of the kind of data and the format used to request token for Application (App) configuration URL from the Connector Service. To get the up-to-date CRD and show the output in the yaml format, run this command:

kubectl get crd tokenrequests.applicationconnector.kyma-project.io -o yaml

Sample custom resource

This is a sample custom resource (CR) which allows to get the configuration required to connect an external solution to the test App.

apiVersion: applicationconnector.kyma-project.io/v1alpha1
kind: TokenRequest
metadata:
  name: test-app
context:
  tenant: test-tenant
  group: test-group

Custom resource parameters

This table lists all the possible parameters of a given resource together with their descriptions:

Additional information

When you fetch an existing TokenRequest CR, the system adds the status section which describes the status of the request and lists the configuration details. This table lists the fields of the status section.

After you create an Application (App), connect it to an external solution to consume the solution's APIs and Event catalogs in Kyma. To accomplish this, get the client certificate for the external solution and register its services.

This guide shows you how to get the client certificate.

NOTE: The client certificate is valid for 92 days. See this tutorial to learn how to renew the client certificate. You can also revoke the client certificate, which prevents it from being renewed. See this tutorial to learn how to do this.

Prerequisites

• OpenSSL toolkit to create a Certificate Signing Request (CSR), keys, and certificates which fulfil high security standards

Get the configuration URL with a token

To get the configuration URL which allows you to fetch the required configuration details, create a TokenRequest custom resource (CR). The controller which handles this CR kind adds the status section to the created CR. The status section contains the required configuration details.

• Create a TokenRequest CR. The CR name must match the name of the App for which you want to get the configuration details. Run:

  Click to copy

  cat <<EOF | kubectl apply -f -
  apiVersion: applicationconnector.kyma-project.io/v1alpha1
  kind: TokenRequest
  metadata:
    name: {APP_NAME}
  EOF

• Fetch the TokenRequest CR you created to get the configuration details from the status section. Run:

  Click to copy

  kubectl get tokenrequest.applicationconnector.kyma-project.io {APP_NAME} -o yaml

  NOTE: If the response doesn't contain the status section, wait for a few moments and fetch the CR again.

  A successful call returns the following response:

  Click to copy

  apiVersion: applicationconnector.kyma-project.io/v1alpha1
  kind: TokenRequest
  metadata:
    name: {APP_NAME}
  status:
    expireAfter: 2018-11-22T18:38:44Z
    application: {APP_NAME}
    state: OK
    token: h31IwJiLNjnbqIwTPnzLuNmFYsCZeUtVbUvYL2hVNh6kOqFlW9zkHnzxYFCpCExBZ_voGzUo6IVS_ExlZd4muQ==
    url: https://connector-service.kyma.local/v1/applications/signingRequests/info?token=h31IwJiLNjnbqIwTPnzLuNmFYsCZeUtVbUvYL2hVNh6kOqFlW9zkHnzxYFCpCExBZ_voGzUo6IVS_ExlZd4muQ==

Get the CSR information and configuration details from Kyma

Use the link you got in the previous step to fetch the CSR information and configuration details required to connect your external solution. Run:

curl {CONFIGURATION_URL_WITH_TOKEN}

NOTE: The URL you call in this step contains a token that is valid for 5 minutes or for a single call. You get a code 403 error if you call the same configuration URL more than once, or if you call an URL with an expired token.

A successful call returns the following response:

{
    "csrUrl": "{CSR_SIGNING_URL_WITH_TOKEN}",
    "api":{
        "metadataUrl":      "https://gateway.{CLUSTER_DOMAIN}/{APP_NAME}/v1/metadata/services",
        "eventsUrl":        "https://gateway.{CLUSTER_DOMAIN}/{APP_NAME}/v1/events",
        "infoUrl":          "https://gateway.{CLUSTER_DOMAIN}/v1/applications/management/info",
        "certificatesUrl":  "https://connector-service.{CLUSTER_DOMAIN}/v1/applications/certificates",
    },
    "certificate":{
        "subject":"OU=Test,O=TestOrg,L=Waldorf,ST=Waldorf,C=DE,CN={APP_NAME}",
        "extensions": "",
        "key-algorithm": "rsa2048",
    }
}

NOTE: The response contains URLs to the Application Registry API and the Events Service API, however, it is not recommended to use them. You should call the metadata endpoint URL, which is provided in api.infoUrl property, to fetch correct URLs to the Application Registry API and to the Events Service API, and other configuration details.

Generate a CSR and send it to Kyma

Generate a CSR using the certificate subject data obtained in the previous step:

openssl genrsa -out generated.key 2048
openssl req -new -sha256 -out generated.csr -key generated.key -subj "/OU=Test/O=TestOrg/L=Waldorf/ST=Waldorf/C=DE/CN={APP_NAME}"
openssl base64 -in generated.csr

Send the encoded CSR to Kyma. Run:

curl -H "Content-Type: application/json" -d '{"csr":"BASE64_ENCODED_CSR_HERE"}' {CSR_SIGNING_URL_WITH_TOKEN}

The response contains a valid client certificate signed by the Kyma Certificate Authority.

{
    "crt":"BASE64_ENCODED_CRT_CHAIN",
    "clientCrt":"BASE64_ENCODED_CLIENT_CRT",
    "caCrt":"BASE64_ENCODED_CA_CRT"
}

After you receive the certificate, decode it and use it in your application.

Call the metadata endpoint

Call the metadata endpoint with the generated certificate to get URLs to the following:

• the Application Registry API
• the Events Service API
• the certificate renewal endpoint
• the certificate revocation endpoint

The URL to the metadata endpoint is returned in the response body from the configuration URL. Use the value of the api.infoUrl property to get the URL. Run:

curl {CLUSTER_DOMAIN}/v1/applications/management/info --cert {CERT_FILE_NAME}.crt --key {KEY_FILE_NAME}.key

A successful call returns the following response:

{
  "clientIdentity": {
    "application": "{APP_NAME}"
  },
  "urls": {
    "metadataUrl": "https://gateway.{CLUSTER_DOMAIN}/{APP_NAME}/v1/metadata/services",
    "eventsUrl": "https://gateway.{CLUSTER_DOMAIN}/{APP_NAME}/v1/events",
    "renewCertUrl": "https://gateway.{CLUSTER_DOMAIN}/v1/applications/certificates/renewals",
    "revokeCertUrl": "https://gateway.{CLUSTER_DOMAIN}/v1/applications/certificates/revocations"
  },
  "certificate": {
    "subject": "OU=Test,O=Test,L=Blacksburg,ST=Virginia,C=US,CN={APP_NAME}",
    "extensions": "string",
    "key-algorithm": "rsa2048"
  }
}

Use urls.metadataUrl and urls.eventsUrl to get the URLs to the Application Registry API and to the Events API.

Call the Application Registry and Event services on local deployment

Since Kyma installation on Minikube uses the self-signed certificate by default, skip TLS verification.

Call the Application Registry with this command:

curl https://gateway.kyma.local/{APP_NAME}/v1/metadata/services --cert {CERT_FILE_NAME}.crt --key {KEY_FILE_NAME}.key -k

Use this command to call the Event services:

curl https://gateway.kyma.local/{APP_NAME}/v1/events --cert {CERT_FILE_NAME}.crt --key {KEY_FILE_NAME}.key -k

This guide shows you how to register a service of your external solution in Kyma.

Prerequisites

Valid certificate signed by the Kyma Certificate Authority.

Register a service

1. To register a service with a Basic Authentication-secured API, follow this template to prepare the request body:

   NOTE: Follow this tutorial to learn how to register APIs secured with different security schemes or protected against cross-site request forgery (CSRF) attacks.

   Click to copy

   {
     "provider": "example-provider",
     "name": "example-name",
     "description": "This is the long description of your service",
     "shortDescription": "Short description",
     "labels": {
       "example": "true"
     },
     "api": {
       "targetUrl": "https://httpbin.org/",
       "spec": {},
       "requestParameters": {
         "queryParameters": {
           "param": ["bar"]
         },
         "headers": {
           "custom-header": ["foo"]
         }
       },
       "credentials": {
         "basic": {
           "username": "{USERNAME}",
           "password": "{PASSWORD}"
         }
       }
     },
     "events": {
       "spec": {
         "asyncapi": "1.0.0",
         "info": {
           "title": "PetStore Events",
           "version": "1.0.0",
           "description": "Description of all the events"
         },
         "baseTopic": "stage.com.some.company.system",
         "topics": {
           "petCreated.v1": {
             "subscribe": {
               "summary": "Event containing information about new pet added to the Pet Store.",
               "payload": {
                 "type": "object",
                 "properties": {
                   "pet": {
                     "type": "object",
                     "required": [
                       "id",
                       "name"
                     ],
                     "example": {
                       "id": "4caad296-e0c5-491e-98ac-0ed118f9474e",
                       "category": "mammal",
                       "name": "doggie"
                     },
                     "properties": {
                       "id": {
                         "title": "Id",
                         "description": "Resource identifier",
                         "type": "string"
                       },
                       "name": {
                         "title": "Name",
                         "description": "Pet name",
                         "type": "string"
                       },
                       "category": {
                         "title": "Category",
                         "description": "Animal category",
                         "type": "string"
                       }
                     }
                   }
                 }
               }
             }
           }
         }
       }
     },
     "documentation": {
       "displayName": "Documentation",
       "description": "Description",
       "type": "some type",
       "tags": ["tag1", "tag2"],
       "docs": [
           {
           "title": "Documentation title...",
           "type": "type",
           "source": "source"
           }
       ]
     }
   }

2. Include the request body you prepared in the following call to register a service:

   Click to copy

   curl -X POST -d '{YOUR_REQUEST_BODY}' https://gateway.{CLUSTER_DOMAIN}/{APP_NAME}/v1/metadata/services --cert {CERT_FILE_NAME}.crt --key {KEY_FILE_NAME}.key -k

   A successful response returns the ID of the registered service:

   Click to copy

   {"id":"{YOUR_SERVICE_ID}"}

Check the details of a registered service

curl https://gateway.{CLUSTER_DOMAIN}/{APP_NAME}/v1/metadata/services/{YOUR_SERVICE_ID} --cert {CERT_FILE_NAME}.crt --key {KEY_FILE_NAME}.key -k

Register API with a specification URL

The Application Registry allows you to pass API specifications in a form of specification URLs.

To register API with specification URL, replace api.spec with api.specificationUrl.

NOTE: If both api.spec and api.specificationUrl are provided, api.spec will be used due to its higher priority.

See the example of the API part of the request body with specification URL:

"api": {
  "targetUrl": "https://services.odata.org/OData/OData.svc",
  "specificationUrl": "https://services.odata.org/OData/OData.svc/$metadata",
  "credentials": {
    "basic": {
      "username": "{USERNAME}",
      "password": "{PASSWORD}"
    }
}

NOTE: Fetching specification from a URL is supported only for APIs. Fetching specifications for Events or documentation is not supported.

Register an API with a secured specification URL

The Application Registry allows you to register an API with a secured specification URL. The supported authentication methods are Basic Authentication and OAuth. You can specify only one type of authentication for an API.

Register an API with a Basic Authentication-secured specification URL

To register an API with a specification URL secured with Basic Authentication, add a specificationCredentials.basic object to the api section of the service registration request body. You must include these fields:

This is an example of the api section of the request body for an API with a specification URL secured with Basic Authentication:

    "api": {
        "targetUrl": "https://sampleapi.targeturl/v1",
        "specificationUrl": "https://sampleapi.spec/v1",
        "specificationCredentials": {
            "basic": {
                "username": "{USERNAME}",
                "password": "{PASSWORD}"
            },
        }  

Register an API with an OAuth-secured specification URL

To register an API with a specification URL secured with OAuth, add a specificationCredentials.oauth object to the api section of the service registration request body. You must include these fields:

This is an example of the api section of the request body for an API with a specification URL secured with OAuth:

    "api": {
        "targetUrl": "https://sampleapi.targeturl/v1",
        "specificationUrl": "https://sampleapi.spec/v1",
        "specificationCredentials": {
            "oauth": {
                "url": "https://sampleapi.targeturl/authorizationserver/oauth/token",
                "clientId": "{CLIENT_ID}",
                "clientSecret": "{CLIENT_SECRET}"
            },
        }  

Use custom headers and query parameters for fetching API specification from URL

You can specify additional headers and query parameters that will be injected to requests to the specification URL.

NOTE: These headers and query parameters are used only for requests for fetching an API specification and are not stored in the system.

To register an API with a specification URL that requires specific custom headers and query parameters, add the specificationRequestParameters.headers and specificationRequestParameters.queryParameters objects to the api section of the service registration request body.

    "api": {
        "targetUrl": "https://sampleapi.targeturl/v1",
        "specificationUrl": "https://sampleapi.spec/v1",
        "specificationRequestParameters": {
            "headers": {
                "custom-header": ["foo"]
            },
            "queryParameters": {
                "param": ["bar"]
            },
        }
        "credentials": {
            "basic": {
                "username": "{USERNAME}",
                "password": "{PASSWORD}"
            },
        }

Register an OData API

If the api.spec or api.specificationUrl parameters are not specified and the api.type parameter is set to OData, the Application Registry will try to fetch specification from the target URL with the $metadata path.

For example, for the service with the following API, the Application Registry will try to fetch API specification from https://services.odata.org/OData/OData.svc/$metadata.

"api": {
  "targetUrl": "https://services.odata.org/OData/OData.svc",
  "apiType": "OData"
  "credentials": {
    "basic": {
      "username": "{USERNAME}",
      "password": "{PASSWORD}"
    }
}

The Application Registry allows you to register a secured API for every service. The supported authentication methods are Basic Authentication, OAuth, and client certificates.

You can specify only one authentication method for every secured API you register. If you try to register and specify more than one authentication method, the Application Registry returns a 400 code response.

Additionally, you can secure the API against cross-site request forgery (CSRF) attacks. CSRF tokens are an additional layer of protection and can accompany any authentication method.

NOTE: Registering a secured API is a part of registering services of an external solution connected to Kyma. To learn more about this process, follow this tutorial.

Register a Basic Authentication-secured API

To register an API secured with Basic Authentication, add a credentials.basic object to the api section of the service registration request body. You must include these fields:

This is an example of the api section of the request body for an API secured with Basic Authentication:

    "api": {
        "targetUrl": "https://sampleapi.targeturl/v1",
        "credentials": {
            "basic": {
                "username": "{USERNAME}",
                "password": "{PASSWORD}"
            },
        }  

Register an OAuth-secured API

To register an API secured with OAuth, add a credentials.oauth object to the api section of the service registration request body. You must include these fields:

This is an example of the api section of the request body for an API secured with OAuth:

    "api": {
        "targetUrl": "https://sampleapi.targeturl/v1",
        "credentials": {
            "oauth": {
                "url": "https://sampleapi.targeturl/authorizationserver/oauth/token",
                "clientId": "{CLIENT_ID}",
                "clientSecret": "{CLIENT_SECRET}"
            },
        }  

Register a client certificate-secured API

To register an API and secure it with client certificates, you must add the credentials.certificateGen object to the api section of the service registration request body. The Application Registry generates a ready to use certificate and key pair for every API registered this way. You can use the generated pair or replace it with your own certificate and key.

Include this field in the service registration request body:

This is an example of the api section of the request body for an API secured with generated client certificates:

    "api": {
        "targetUrl": "https://sampleapi.targeturl/v1",
        "credentials": {
            "certificateGen": {
                "commonName": "{CERT_NAME}"
            },
        }  

NOTE: If you update the registered API and change the certificateGen.commonName, the Application Registry generates a new certificate-key pair for that API. When you delete an API secured with generated client certificates, the Application Registry deletes the corresponding certificate and key.

Details

When you register an API with the credentials.certificateGen object, the Application Registry generates a SHA256withRSA-encrypted certificate and a matching key. To enable communication between Kyma and an API secured with this authentication method, set the certificate as a valid authentication medium for all calls coming from Kyma in your external solution.

You can retrieve the client certificate by sending the following request:

curl https://gateway.{CLUSTER_DOMAIN}/{APP_NAME}/v1/metadata/services/{YOUR_SERVICE_ID} --cert {CERT_FILE_NAME}.crt --key {KEY_FILE_NAME}.key -k

A successful call will return a response body with the details of a registered service and a base64-encoded client certificate.

The certificate and key pair is stored in a Secret in the kyma-integration Namespace. List all Secrets and find the one created for your API:

kubectl -n kyma-integration get secrets

To fetch the certificate and key encoded with base64, run this command:

kubectl -n kyma-integration get secrets app-{APP_NAME}-{SERVICE_ID} -o yaml

NOTE: Replace the APP_NAME placeholder with the name of the Application used to connect the external solution that is the origin of the API. Replace the SERVICE_ID placeholder with the ID of the registered service to which the API belongs. You get this ID after you register an external solution's service in Kyma.

If the API you registered provides a certificate-key pair or the generated certificate doesn't meet your security standards or specific needs, you can use a custom certificate-key pair for authentication. To replace the Kyma-generated pair with your certificate and key, run this command:

kubectl -n kyma-integration patch secrets app-{APP_NAME}-{SERVICE_ID} --patch 'data:
  crt: {BASE64_ENCODED_CRT}
  key: {BASE64_ENCODED_KEY}'

Register a CSRF-protected API

The Application Registry supports CSRF tokens as an additional layer of API protection. To register a CSRF-protected API, add the credentials.{AUTHENTICATION_METHOD}.csrfInfo object to the api section of the service registration request body.

Include this field in the service registration request body:

This is an example of the api section of the request body for an API secured with both Basic Authentication and a CSRF token.

    "api": {
        "targetUrl": "https://sampleapi.targeturl/v1",
        "credentials": {
            "basic": {
                "username": "{USERNAME}",
                "password": "{PASSWORD}",
                "csrfInfo": {
                    "tokenEndpointURL": "{TOKEN_ENDPOINT_URL}"
                }
            },
        }

Use headers and query parameters for custom authentication

You can specify additional headers and query parameters that will be injected to requests to the target API. The Kubernetes Secret stores headers and query parameters which you can use for custom authentication methods.

This is an example of the api section of the request body for an API secured with Basic Authentication. It is enriched with the custom-header header with the foo value, and the param query parameter with the bar value.

    "api": {
        "targetUrl": "https://sampleapi.targeturl/v1",
        "requestParameters": {
            "headers": {
                "custom-header": ["foo"]
            },
            "queryParameters": {
                "param": ["bar"]
            },
        }
        "credentials": {
            "basic": {
                "username": "{USERNAME}",
                "password": "{PASSWORD}"
            },
        }

To create a simple lambda function and trigger it with an event, you must first register a service using the Application Registry that is a part of the Application Connector. This service then sends the event that triggers the lambda. You must create a Service Instance which enables this event in the Namespace. Follow this guide to learn how to do it.

Prerequisites

• An Application bound to a Namespace.
• Client certificates generated for the connected Application.

NOTE: See the respective tutorials to learn how to create an Application, get the client certificate, and bind an Application to a Namespace.

Steps

1. Export the name of the Namespace to which you bound your Application, and the name of your Application.

   Click to copy

   export NAMESPACE={YOUR_NAMESPACE}
   export APP_NAME={YOUR_APPLICATION_NAME}

2. Register a service with events in the desired Application. Use the example AsyncAPI specification.

   NOTE: See this tutorial to learn how to register a service.

   Click to copy

   {
     "name": "my-events-service",
     "provider": "myCompany",
     "Identifier": "identifier",
     "description": "This is some service",
     "events": {
       "spec": {
         "asyncapi": "2.0.0",
         "info": {
           "title": "Example Events",
           "version": "2.0.0",
           "description": "Description of all the example events"
         },
         "channels": {
           "example/events/com/exampleEvent/v1": {
             "subscribe": {
               "message": {
                 "summary": "Example event",
                 "payload": {
                   "type": "object",
                   "properties": {
                     "myObject": {
                       "type": "object",
                       "required": [
                         "id"
                       ],
                       "example": {
                         "id": "4caad296-e0c5-491e-98ac-0ed118f9474e"
                       },
                       "properties": {
                         "id": {
                           "title": "Id",
                           "description": "Resource identifier",
                           "type": "string"
                         }
                       }
                     }
                   }
                 }
               }
             }
           }
         }
       }
     }
   }

3. Expose the externalName of the Service Class of the registered service.

   Click to copy

   export EXTERNAL_NAME=$(kubectl -n $NAMESPACE get serviceclass {SERVICE_ID}  -o jsonpath='{.spec.externalName}')

4. Create a Service Instance for the registered service.

   Click to copy

   cat <<EOF | kubectl apply -f -
   apiVersion: servicecatalog.k8s.io/v1beta1
   kind: ServiceInstance
   metadata:
     name: my-events-service-instance-name
     namespace: $NAMESPACE
   spec:
     serviceClassExternalName: $EXTERNAL_NAME
   EOF

5. Create and register a lambda function in your Namespace.

   Click to copy

   cat <<EOF | kubectl apply -f -
   apiVersion: kubeless.io/v1beta1
   kind: Function
   metadata:
     name: my-events-lambda
     namespace: $NAMESPACE
     labels:
       app: my-events-lambda
   spec:
     deployment:
       spec:
         template:
           spec:
             containers:
             - name: ""
               resources: {}
     deps: |-
       {
           "name": "example-1",
           "version": "0.0.1",
           "dependencies": {
             "request": "^2.85.0"
           }
       }
     function: |-
       const request = require('request');
       module.exports = { main: function (event, context) {
           return new Promise((resolve, reject) => {
               const url = \`http://httpbin.org/uuid\`;
               const options = {
                   url: url,
               };
               sendReq(url, resolve, reject)
           })
       } }
       function sendReq(url, resolve, reject) {
           request.get(url, { json: true }, (error, response, body) => {
               if(error){
                   resolve(error);
               }
                 console.log("Response acquired successfully! Uuid: " + response.body.uuid);
               resolve(response);
           })
       }
     function-content-type: text
     handler: handler.main
     horizontalPodAutoscaler:
       spec:
         maxReplicas: 0
     runtime: nodejs8
     service:
       ports:
       - name: http-function-port
         port: 8080
         protocol: TCP
         targetPort: 8080
       selector:
         created-by: kubeless
         function: my-events-lambda
     timeout: ""
     topic: exampleEvent
   EOF

6. Create a Subscription to allow events to trigger the lambda function.

   Click to copy

   cat <<EOF | kubectl apply -f -
   apiVersion: eventing.kyma-project.io/v1alpha1
   kind: Subscription
   metadata:
     labels:
       Function: my-events-lambda
     name: lambda-my-events-lambda-exampleevent-v1
     namespace: $NAMESPACE
   spec:
     endpoint: http://my-events-lambda.$NAMESPACE:8080/
     event_type: exampleevent
     event_type_version: v1
     include_subscription_name_header: true
     source_id: $APP_NAME
   EOF

7. Send an event to trigger the created lambda.

   Click to copy

   curl -X POST https://gateway.{CLUSTER_DOMAIN}/$APP_NAME/v1/events -k --cert {CERT_FILE_NAME}.crt --key {KEY_FILE_NAME}.key -d \
   '{
       "event-type": "exampleevent",
       "event-type-version": "v1",
       "event-id": "aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa",
       "event-time": "2018-10-16T15:00:00Z",
       "data": "some data"
   }'

8. Check the logs of the lambda function to see if it was triggered. Every time an event successfully triggers the function, this message appears in the logs: Response acquired successfully! Uuid: {RECEIVED_UUID}.

   Click to copy

   kubectl -n $NAMESPACE logs "$(kubectl -n $NAMESPACE get po -l function=my-events-lambda -o jsonpath='{.items[0].metadata.name}')" -c my-events-lambda | grep -E "Response acquired successfully! Uuid: [a-f0-9-]+"

This guide shows how to call a registered external service from Kyma using a simple lambda function.

Prerequisites

• An Application (App) bound to the production Namespace
• Client certificates generated for the connected App.
• Map my-lambda-production.kyma.local to your Minikube IP to call the lambda function on a local Kyma deployment.

Steps

1. Register a service with the following specification to the desired Application.

   NOTE: See this tutorial to learn how to register a service.

   Click to copy

   {
     "name": "my-service",
     "provider": "myCompany",
     "Identifier": "identifier",
     "description": "This is some service",
     "api": {
       "targetUrl": "http://httpbin.org/",
       "spec": {
         "swagger":"2.0"
       }
     }
   }

2. Get the externalName of the Service Class of the registered service.

   Click to copy

   kubectl -n production get serviceclass {SERVICE_ID}  -o jsonpath='{.spec.externalName}'

3. Create a Service Instance for the registered service.

   Click to copy

   cat <<EOF | kubectl apply -f -
   apiVersion: servicecatalog.k8s.io/v1beta1
   kind: ServiceInstance
   metadata:
     name: my-service-instance-name
     namespace: production
   spec:
     serviceClassExternalName: {EXTERNAL_NAME}
   EOF

4. Create a lambda function that sends a request to the registered service with an additional path of /uuid. A successful response returns a UUID generated by httpbin.org. To create and register the lambda function in the production Namespace, run:

   Click to copy

   cat <<EOF | kubectl apply -f -
   apiVersion: kubeless.io/v1beta1
   kind: Function
   metadata:
     name: my-lambda
     namespace: production
     labels:
       app: my-lambda
   spec:
     deployment:
       spec:
         template:
           metadata:
             labels:
               {APP_NAME}-{SERVICE_ID}: "true"
           spec:
             containers:
             - env:
               - name: GATEWAY_URL
                 value: {APP_NAME}-{SERVICE_ID}.kyma-integration
     deps: |-
       {
           "name": "example-1",
           "version": "0.0.1",
           "dependencies": {
             "request": "^2.85.0"
           }
       }
     function: |-
       const request = require('request');
       module.exports = { main: function (event, context) {
           return new Promise((resolve, reject) => {
               const url = \`http://\${process.env.GATEWAY_URL}/uuid\`;
               const options = {
                   url: url,
               };
               sendReq(url, resolve, reject)
           })
       } }
       function sendReq(url, resolve, reject) {
           request.get(url, { json: true }, (error, response, body) => {
               if(error){
                   resolve(error);
               }
               resolve(response.body);
           })
       }
     function-content-type: text
     handler: handler.main
     horizontalPodAutoscaler:
       spec:
         maxReplicas: 0
     runtime: nodejs8
     service:
       ports:
       - name: http-function-port
         port: 8080
         protocol: TCP
         targetPort: 8080
       selector:
         created-by: kubeless
         function: my-lambda
     timeout: ""
     topic: http
   EOF

5. Create a ServiceBinding and a ServiceBindingUsage to bind the Service Instance to the lambda function.

   Click to copy

   cat <<EOF | kubectl apply -f -
   apiVersion: servicecatalog.k8s.io/v1beta1
   kind: ServiceBinding
   metadata:
     labels:
       Function: my-lambda
     name: my-service-binding
     namespace: production
   spec:
     instanceRef:
       name: my-service-instance-name
   EOF

   Click to copy

   cat <<EOF | kubectl apply -f -
   apiVersion: servicecatalog.kyma-project.io/v1alpha1
   kind: ServiceBindingUsage
   metadata:
     labels:
       Function: my-lambda
       ServiceBinding: my-service-binding
     name: my-service-binding
     namespace: production
   spec:
     serviceBindingRef:
       name: my-service-binding
     usedBy:
       kind: function
       name: my-lambda
   EOF

6. To expose the lambda function outside the cluster create an Api custom resource:

   Click to copy

   cat <<EOF | kubectl apply -f -
   apiVersion: gateway.kyma-project.io/v1alpha2
   kind: Api
   metadata:
     labels:
       function: my-lambda
     name: my-lambda
     namespace: production
   spec:
     authentication: []
     hostname: my-lambda-production.{CLUSTER_DOMAIN}
     service:
       name: my-lambda
       port: 8080
   EOF

7. To verify that everything was setup correctly you can now call the lambda through https:

• On a cluster

  Click to copy

  curl https://my-lambda-production.{CLUSTER_DOMAIN}/ -k

• On a local deployment:

  Click to copy

  curl https://my-lambda-production.kyma.local/ -k

  A successful response returns a UUID generated by httpbin.org:

  Click to copy

  {
    "uuid": "d44cc373-b26e-4a36-9890-6418d131a285"
  }

This guide shows you how to bind an Application (App) to a Namespace in Kyma. To execute the binding, create an ApplicationMapping custom resource in the cluster. Follow the instructions to bind your App to the production Namespace.

Prerequisites

To complete this guide, your cluster must have at least one App created.

Steps

1. List all Apps bound to the production Namespace:

   Click to copy

   kubectl get em -n production

2. Bind an App to a Namespace. Run this command to create an ApplicationMapping custom resource and apply it to the cluster:

   Click to copy

   cat <<EOF | kubectl apply -f -
   apiVersion: applicationconnector.kyma-project.io/v1alpha1
   kind: ApplicationMapping
   metadata:
     name: {NAME_OF_APP_TO_BIND}
     namespace: production
   EOF

3. Check if the operation is successful. List all Namespaces to which your App is bound:

   Click to copy

   kubectl get em --all-namespaces -o jsonpath='{range .items[?(@.metadata.name=="{NAME_OF_YOUR_APP}")]}{@.metadata.namespace}{""}{end}'

By default, the client certificate you generate when you connect an external solution to Kyma is valid for 92 days. Follow this tutorial to renew the client certificate.

NOTE: You can only renew client certificates that are still valid. If your client certificate is expired or revoked, you must generate a new one.

1. To renew the client certificate, use the same certificate subject that matches the subject of your current certificate. To check the certificate subject, run:

   Click to copy

   openssl x509 -noout -subject -in {PATH_TO_OLD_CRT}

2. Generate a new CSR using the certificate subject you got in the previous step. Run:

   Click to copy

   openssl req -new -sha256 -out renewal.csr -key {PATH_TO_KEY} -subj "{SUBJECT}"

3. Send a request to the Connector Service to renew the certificate:

   Click to copy

   curl -X POST https://gateway.{DOMAIN}/v1/applications/certificates/renewals -d '{"csr":"BASE64_ENCODED_CSR"}' -k --cert {PATH_TO_OLD_CRT} --key {PATH_TO_KEY}

   A successful call returns a renewed client certificate:

   Click to copy

   {
       "crt":"BASE64_ENCODED_CRT_CHAIN",
       "clientCrt":"BASE64_ENCODED_CLIENT_CRT",
       "caCrt":"BASE64_ENCODED_CA_CRT"
   }

You can revoke a client certificate generated for your Application. Revocation prevents a certificate from being renewed. A revoked certificate, however, continues to be valid until it expires.

To revoke a client certificate, send a request to the certificates/revocations endpoint. Pass the certificate you want to revoke and a key that matches this certificate in the call. Run:

curl -X POST https://gateway.{CLUSTER_DOMAIN}/v1/applications/certificates/revocations --cert {CERT_TO_REVOKE} --key {CERT_TO_REVOKE_KEY} -k 

Revoke a certificate using SHA256 fingerprint

If you have admin access to the Kyma cluster, you can revoke client certificates by sending the SHA256 fingerprint of a certificate to the internal certificates/revocations endpoint. Follow these steps:

1. Convert the certificate from the pem format to the der format. Run:
   Click to copy

   openssl x509 -in {CLIENT_CERT_FILE}.crt -outform der -out {CLIENT_CERT_DER_FILE}.der

2. Get the SHA256 fingerprint of the certificate. Run:
   Click to copy

   shasum -a 256 {CLIENT_CERT_DER_FILE}.der

3. Revoke the certificate using the SHA256 fingerprint:
   Click to copy

   curl -X POST http://connector-service-internal-api:8080/v1/applications/certificates/revocations -d '{hash: {SHA256_FINGERPRINT_OF_CERT_TO_REVOKE_}}'

The Central Connector Service uses the Root CA certificate to issue new certificates for runtimes and by the Istio Ingress Gateway to validate their identity.

Two different components use the Root CA certificate. As a result, the certificate is stored in two separate Secrets:

• The connector-service-app-ca Connector Service CA Secret responsible for signing certificate requests
• The application-connector-certs Istio Secret responsible for security in the Connector Service API

Keeping both Secrets up-to-date is vital for the security of your implementation as it guarantees that the Connector Service issues proper certificates and no unregistered applications can access its API.

The Root CA certificate has a set expiration date and must be renewed periodically to prevent its expiration. You must also renew the Root CA certificate and key every time they are compromised.

This tutorial describes the procedure you must follow for these scenarios:

• Rotating a soon-to-expire Root CA certificate
• Rotating a compromised Root CA certificate
• Rotating a compromised Root CA key

Rotating a soon-to-expire CA certificate

To successfully rotate a soon-to-expire CA certificate, replace it with a new certificate in both the Connector Service CA Secret and the Istio Secret. Follow these steps to replace the old certificate in both Secrets:

1. Get the existing Root CA key. Fetch it from the connector-service-app-ca Secret and save it to a ca.key file. Run:

   Click to copy

   kubectl -n kyma-integration get secret connector-service-app-ca -o=jsonpath='{.data.ca\.key}' | base64 --decode > ca.key

2. Generate a new certificate for the key you obtained and save it to a new-ca.crt file. Run:

   Click to copy

   openssl req -new -key ca.key -x509 -sha256 -days {TTL_DAYS} -nodes -out new-ca.crt

   NOTE: Use the -days flag to set the TTL of the newly generated certificate.

3. Encode the newly created certificate with base64:

   Click to copy

   cat new-ca.crt | base64

4. Replace the old certificate in the Connector Service CA Secret. Edit the Secret and replace the ca.crt value with the new base64-encoded certificate. Run:

   Click to copy

   kubectl -n kyma-integration edit secret connector-service-app-ca

5. Get the existing Istio CA certificate. Fetch it from the application-connector-certs Secret and save it to a old-ca.crt file. Run:

   Click to copy

   kubectl -n istio-system get secret application-connector-certs -o=jsonpath='{.data.ca\.crt}' | base64 --decode > old-ca.crt

6. Merge the old Nginx certificate and the newly generated certificate into a single nginx-ca.crt file:

   Click to copy

   cat old-ca.crt new-ca.crt > merged-ca.crt

7. Encode the newly created merged-ca.crt certificate file with base64:

   Click to copy

   cat merged-ca.crt | base64

8. Replace the old certificate in the Istio Secret. Edit the Secret and replace the ca.crt value with the merged-ca.crt base64-encoded certificate. Run:

   Click to copy

   kubectl -n istio-system edit secret application-connector-certs

9. Renew the certificates in a runtime. To do that, create a CertificateRequest CR in the runtime in which you want to renew the certificates. Alternatively, wait for the certificates to expire in a given runtime. The system renews the certificates automatically using the information stored in the Secrets you updated.

10. After the certificates are renewed in a runtime, remove the application-connector-certs Secret entry which contains the old certificate. First, encode the new-ca.crt file with base64:

    Click to copy

    cat new-ca.crt | base64

11. Edit the Secret and replace the ca.crt value with the new-ca.crt base64-encoded certificate. Run:

    Click to copy

    kubectl -n istio-system edit secret application-connector-certs

Rotating a compromised Root CA certificate

1. Get the existing Root CA key. Fetch it from the connector-service-app-ca Secret and save it to a ca.key file. Run:

   Click to copy

   kubectl -n kyma-integration get secret connector-service-app-ca -o=jsonpath='{.data.ca\.key}' | base64 --decode > ca.key

2. Generate a new certificate for the key you obtained and save it to a new-ca.crt file. Run:

   Click to copy

   openssl req -new -key ca.key -x509 -sha256 -days {TTL_DAYS} -nodes -out new-ca.crt

   NOTE: Use the -days flag to set the TTL of the newly generated certificate.

3. Encode the newly created certificate with base64:

   Click to copy

   cat new-ca.crt | base64

4. Replace the old certificate in the Connector Service CA Secret. Edit the Secret and replace ca.crt value with the new base64-encoded certificate. Run:

   Click to copy

   kubectl -n kyma-integration edit secret connector-service-app-ca

5. Replace the old certificate in the Istio Secret. Edit the Secret and replace the ca.crt value with the new base64-encoded certificate. Run:

   Click to copy

   kubectl -n istio-system edit secret application-connector-certs

6. Generate new certificates in a runtime. To do that, create a CertificateRequest CR in the runtime in which you want to generate the certificates.

Rotating a compromised root CA key

1. Generate a new, RSA-encoded root CA key and save to a new-ca.key file:

   Click to copy

   openssl genrsa -out new-ca.key 4096

2. Generate a new certificate using the key you generated and save it to a new-ca.crt file. Run:

   Click to copy

   openssl req -new -key new-ca.key -x509 -sha256 -days {EXPIRATION_DAYS} -nodes -out new-ca.crt

   NOTE: Use the -days flag to set the TTL of the newly generated certificate.

3. Encode the newly created certificate and key with base64:

   Click to copy

   cat new-ca.key | base64

   Click to copy

   cat new-ca.crt | base64

4. Replace the old certificate and key in the Connector Service CA Secret. Edit the Secret and replace the ca.crt and ca.key values with the new base64-encoded certificate and key respectively. Run:

   Click to copy

   kubectl -n kyma-integration edit secret connector-service-app-ca

5. Replace the old certificate in the Istio Secret. Edit the Secret and replace the ca.crt value with the new base64-encoded certificate. Run:

   Click to copy

   kubectl -n istio-system edit secret application-connector-certs

6. Generate new certificates in a runtime. To do that, create a CertificateRequest CR in the runtime in which you want to generate the certificates.

You can get the API specification of the Application Registry for a given version of the service using this command:

curl https://gateway.{CLUSTER_DOMAIN}/{APP_NAME}/v1/metadata/api.yaml

TIP: For details on the Application Registry API specification, see this file.

The Event Service provides an endpoint for fetching subscribed Events for the application. To fetch all of them, make a call:

curl https://gateway.{CLUSTER_DOMAIN}/{APP_NAME}/v1/events/subscribed -k --cert {APP_CERT} --key {APP_CERTS_KEY}

The successful call returns a list of all active Events for the application.

TIP: For details on the Event Service API specification, see this file.

If you call a registered service and receive an error, follow these steps to detect the source of the problem:

1. Check the logs.

   Check the logs from Application Gateway Pod to verify that the call reached Application Gateway. To fetch these logs, run this command:

   Click to copy

   kubectl -n kyma-integration logs -l app={APP_NAME}-application-gateway -c {APP_NAME}-application-gateway

   The request that reached the Pod is logged by Application Gateway.

2. Check for Access Service.

   If the call you tried to make is not in the logs, check if an Access Service exists for the service you are trying to call.

   Click to copy

   kubectl -n kyma-integration get svc {APP_NAME}-{SERVICE_ID}

3. Re-register the service.

   If Access Service does not exist, run this command to deregister the service you tried to call:

   • With a trusted certificate
   • Without a trusted certificate

   Then, register the service and try calling again. Registering the service again recreates the Access Service. To register a service, see this tutorial.

4. Check the API URL.

   If your call reaches the Application Gateway and the Access Service exists, but you still receive an error, check if the API URL in the service definition matches the API URL of the actual service you are trying to call. To check the target URL of the API, fetch the Service definition from Application Registry:

   • With a trusted certificate
   • Without a trusted certificate

   A successful call returns a json response with the service definition that contains the target URL. Call the target URL directly to verify that the value of api.targetUrl is correct.

Application Registry - No certificate

If you try to access Application Registry without a client certificate, you get this error:

error:1401E410:SSL routines:CONNECT_CR_FINISHED:sslv3 alert handshake failure

To access Application Registry you need to pass a client certificate with the HTTP request.
To generate a client certificate, see this tutorial.

Application Registry - Expired certificate

If you try to access Application Registry using an expired client certificate, you get this error:

error:1401E415:SSL routines:CONNECT_CR_FINISHED:sslv3 alert certificate expired

To access Application Registry you need to pass a valid client certificate with the request.
To generate a new client certificate, see this tutorial.

Application Registry - Invalid subject

If you try to access Application Registry with the wrong certificate, you get this error:

{"code":403,"error":"No valid subject found"}

Make sure that your certificate is generated for the Application that you are trying to access.
To get the certificate subject, run:

openssl req -noout -subject -in {PATH_TO_CSR_FILE}

You get the certificate subject as a response:

subject=/OU=OrgUnit/O=Organization/L=Waldorf/ST=Waldorf/C=DE/CN={APPLICATION_NAME}

Check that the common name CN matches the name of your Application.
If it does not, generate a new certificate for your Application.

To generate a new client certificate, see this tutorial.

Invalid Certificate Signing Request (CSR)

If you try to generate a client certificate, you may get this error:

{
  "code":403,
  "error":"CSR: Invalid common name provided."
}

This error is caused by applying wrong subject information to your Certificate Signing Request.
To ensure CSR was generated properly, check the values returned by the Connector Service with the call that fetched CSR information:

{
  ...
  "certificate":{
    "subject":"O=Organization,OU=OrgUnit,L=Waldorf,ST=Waldorf,C=DE,CN=CNAME",
    "extensions":"",
    "key-algorithm":"rsa2048"
  }
}

Subject values present in CSR should match the subject in the response that you got.

To check the subject of the generated CSR, run this command:

openssl req -noout -subject -in {PATH_TO_CSR_FILE}