Hybrid Testing ​

Introduction ​

You can easily test your CAP application using a local database and mock ups. But at some point, you're going to want to test with real cloud services. Of course, you can always deploy your application to the cloud.

With hybrid testing capabilities, you can stay in your local development environment and avoid the long turnaround times of cloud deployment, and you can selectively decide which services you want to use from the cloud.

Use the cds bind command to connect your application to services on the cloud. Start your application with the hybrid profile to use these service bindings. You can switch between local mock configuration and cloud service configuration by simply setting or omitting the profile parameter.

Bind to Cloud Services ​

Bind a Local Application to Services on Cloud Foundry ​

cds bind -2 my-hana:my-hana-key

cds bind -2 my-hana:my-hana-key

Binds your CAP application to the service key my-hana-key of the service instance my-hana, using your currently targeted Cloud Foundry space. The service instance my-hana is a managed service. cds bind also supports Cloud Foundry user-provided services.

Learn how to binding to user-provided services on cloud foundry.

Output:

[bind] - Retrieving data from Cloud Foundry...
[bind] - Binding db to Cloud Foundry managed service my-hana:my-hana-key with kind hana.
[bind] - Saving bindings to .cdsrc-private.json in profile hybrid.
[bind] -
[bind] - TIP: Run with cloud bindings: cds watch --profile hybrid

[bind] - Retrieving data from Cloud Foundry...
[bind] - Binding db to Cloud Foundry managed service my-hana:my-hana-key with kind hana.
[bind] - Saving bindings to .cdsrc-private.json in profile hybrid.
[bind] -
[bind] - TIP: Run with cloud bindings: cds watch --profile hybrid

Note: The service key needs to be created beforehand as it is not created by default when using mta deployment.

In many cases, CAP knows which CDS service and kind to use for a cloud service. Like in the previous example, the db CDS service gets bound and set to the hana kind, because the given service instance is of type hana with plan hdi-shared.

Learn how to bind to arbitrary cloud services.

The binding information is stored in the .cdsrc-private.json file of your project in the requires section:

{
  "requires": {
    "[hybrid]": {
      "db": {
        "kind": "hana",
        "binding": {
          "type": "cf",
          "apiEndpoint": "https://api.sap.hana.ondemand.com",
          "org": "your-cf-org",
          "space": "your-cf-space",
          "instance": "my-hana",
          "key": "my-hana-key",
          "vcap": {
            "label": "hana",
            "plan": "hdi-shared"
          },
          "resolved": false
        }
      }
    }
  }
}

{
  "requires": {
    "[hybrid]": {
      "db": {
        "kind": "hana",
        "binding": {
          "type": "cf",
          "apiEndpoint": "https://api.sap.hana.ondemand.com",
          "org": "your-cf-org",
          "space": "your-cf-space",
          "instance": "my-hana",
          "key": "my-hana-key",
          "vcap": {
            "label": "hana",
            "plan": "hdi-shared"
          },
          "resolved": false
        }
      }
    }
  }
}

Bindings are assigned to the hybrid profile by default.

Note that no credentials are saved. Only the information about where the credentials can be obtained is stored on your machine.

All cds bind command line options

Bind a Local Application to User-Provided Services on Cloud Foundry ​

cds bind my-ups -2 my-user-provided-service

cds bind my-ups -2 my-user-provided-service

Binds your CAP application to the user provided service instance my-user-provided-service, using your currently targeted Cloud Foundry space. The service name my-ups is optional - it has to match the service name used in the CDS required services configuration.

Output:

[bind] - Retrieving data from Cloud Foundry...
[bind] - Binding my-ups to Cloud Foundry user provided service my-user-provided-service.
[bind] - Saving bindings to .cdsrc-private.json in profile hybrid.
[bind] -
[bind] - TIP: Run with cloud bindings: cds watch --profile hybrid

[bind] - Retrieving data from Cloud Foundry...
[bind] - Binding my-ups to Cloud Foundry user provided service my-user-provided-service.
[bind] - Saving bindings to .cdsrc-private.json in profile hybrid.
[bind] -
[bind] - TIP: Run with cloud bindings: cds watch --profile hybrid

cds watch --profile hybrid will automatically resolve user-provided service instance bindings using the same technique as for any other managed service binding.

Bind a Local Application to Services on Kubernetes ​

You can bind to Service Bindings of Open Service Broker service instances, such as SAP BTP services, on your Kubernetes cluster and to plain Kubernetes Secrets by adding the --on k8s option to the cds bind command:

cds bind -2 <service binding or secret> --on k8s

cds bind -2 <service binding or secret> --on k8s

The command uses your current Kubernetes context. That is your current server and namespace. You need to be logged in as a precondition.

Bind to Kubernetes Service Bindings ​

To list all Service Bindings in your current Kubernetes context, you can use the kubectl get servicebindings command:

NAME                  SERVICE-INSTANCE      SECRET-NAME           STATUS   AGE
cpapp-xsuaa-binding   cpapp-xsuaa           cpapp-xsuaa-secret    Ready    11s

NAME                  SERVICE-INSTANCE      SECRET-NAME           STATUS   AGE
cpapp-xsuaa-binding   cpapp-xsuaa           cpapp-xsuaa-secret    Ready    11s

Use the service binding name for the -2 option:

cds bind -2 cpapp-xsuaa-binding --on k8s

cds bind -2 cpapp-xsuaa-binding --on k8s

Output:

[bind] - Retrieving data from Kubernetes...
[bind] - Binding uaa to Kubernetes service binding cpapp-xsuaa-binding with kind xsuaa
[bind] - Saving bindings to .cdsrc-private.json in profile hybrid
[bind] -
[bind] - TIP: Run with cloud bindings: cds watch --profile hybrid

[bind] - Retrieving data from Kubernetes...
[bind] - Binding uaa to Kubernetes service binding cpapp-xsuaa-binding with kind xsuaa
[bind] - Saving bindings to .cdsrc-private.json in profile hybrid
[bind] -
[bind] - TIP: Run with cloud bindings: cds watch --profile hybrid

The binding information is stored in the .cdsrc-private.json file of your project in the requires section:

{
  "requires": {
    "[hybrid]": {
      "auth": {
        "binding": {
          "type": "k8s",
          "name": "cpapp-xsuaa-binding",
          "cluster": "https://apiserver.d9a6204.kyma-stage.shoot.live.k8s-hana.ondemand.com",
          "instance": "cpapp-xsuaa",
          "namespace": "dev",
          "secret": "cpapp-xsuaa-secret",
          "resolved": false,
          "vcap": {
            "label": "xsuaa",
            "plan": "application"
          }
        },
        "kind": "xsuaa"
      }
    }
  }
}

{
  "requires": {
    "[hybrid]": {
      "auth": {
        "binding": {
          "type": "k8s",
          "name": "cpapp-xsuaa-binding",
          "cluster": "https://apiserver.d9a6204.kyma-stage.shoot.live.k8s-hana.ondemand.com",
          "instance": "cpapp-xsuaa",
          "namespace": "dev",
          "secret": "cpapp-xsuaa-secret",
          "resolved": false,
          "vcap": {
            "label": "xsuaa",
            "plan": "application"
          }
        },
        "kind": "xsuaa"
      }
    }
  }
}

Bind to Kubernetes Secrets ​

Alternatively, you can bind to Kubernetes Secrets.

You can use the kubectl get secrets command to list all secrets in your current Kubernetes context:

NAME                                    TYPE                                  DATA   AGE
cap-hdi-container                       Opaque                                11     44h

NAME                                    TYPE                                  DATA   AGE
cap-hdi-container                       Opaque                                11     44h

Use the secret name for the -2 option.

You need to provide either the service argument or the --kind option as well, because secrets have no service metadata.

cds bind -2 cap-hdi-container --on k8s --kind hana

cds bind -2 cap-hdi-container --on k8s --kind hana

Output:

[bind] - Retrieving data from Kubernetes...
[bind] - Binding db to Kubernetes secret cap-hdi-container with kind hana
[bind] - Saving bindings to .cdsrc-private.json in profile hybrid
[bind] -
[bind] - TIP: Run with cloud bindings: cds watch --profile hybrid

[bind] - Retrieving data from Kubernetes...
[bind] - Binding db to Kubernetes secret cap-hdi-container with kind hana
[bind] - Saving bindings to .cdsrc-private.json in profile hybrid
[bind] -
[bind] - TIP: Run with cloud bindings: cds watch --profile hybrid

Run with Service Bindings ​

Run CAP Node.js Apps with Service Bindings ​

Now, you can run your CAP service locally using the cloud service bindings:

cds watch --profile hybrid

cds watch --profile hybrid

It will resolve the cloud bindings in your configuration:

1. Bindings to Cloud Foundry: The credentials are downloaded from the service key of the Cloud Foundry API endpoint, org, and space that were targeted when cds bind was being called. This requires you to be logged in to the correct Cloud Foundry API endpoint.
2. Bindings to Kubernetes: The credentials are downloaded from the service bindings and secrets of the Kubernetes cluster and namespace that were in the current context when cds bind was being called.

You can also resolve and display credentials using the cds env command:

cds env get requires.db.credentials --profile hybrid --resolve-bindings

cds env get requires.db.credentials --profile hybrid --resolve-bindings

Example output:

{
  url: 'jdbc:sap://BDB9AC0F20CB46B494E6742047C4F99A.hana.eu10.hanacloud.ondemand.com:443?encrypt=true&validateCertificate=true&currentschema=BDB9AC0F20CB46B494E6742047C4F99A',
  host: 'bdb9ac0f20cb46b494e6742047c4f99a.hana.eu10.hanacloud.ondemand.com',
  port: '443',
  driver: 'com.sap.db.jdbc.Driver',
  schema: 'BDB9AC0F20CB46B494E6742047C4F99A',
  hdi_user: 'BDB9AC0F20CB46B494E6742047C4F99A_DT',
  hdi_password: 'abc...xyz',
  user: 'BDB9AC0F20CB46B494E6742047C4F99A_RT',
  password: 'abc....xyz',
  certificate: '-----BEGIN CERTIFICATE-----\n' +
    '...' +
    '-----END CERTIFICATE-----'
}

{
  url: 'jdbc:sap://BDB9AC0F20CB46B494E6742047C4F99A.hana.eu10.hanacloud.ondemand.com:443?encrypt=true&validateCertificate=true&currentschema=BDB9AC0F20CB46B494E6742047C4F99A',
  host: 'bdb9ac0f20cb46b494e6742047c4f99a.hana.eu10.hanacloud.ondemand.com',
  port: '443',
  driver: 'com.sap.db.jdbc.Driver',
  schema: 'BDB9AC0F20CB46B494E6742047C4F99A',
  hdi_user: 'BDB9AC0F20CB46B494E6742047C4F99A_DT',
  hdi_password: 'abc...xyz',
  user: 'BDB9AC0F20CB46B494E6742047C4F99A_RT',
  password: 'abc....xyz',
  certificate: '-----BEGIN CERTIFICATE-----\n' +
    '...' +
    '-----END CERTIFICATE-----'
}

Run Arbitrary Commands with Service Bindings ​

With cds bind you avoid storing credentials on your hard disk. If you need to start other applications with cloud service bindings from local, then you can use the exec sub command of cds bind.

For example, you can run the approuter from the approuter child directory:

cds bind --exec -- npm start --prefix approuter

cds bind --exec -- npm start --prefix approuter

cds bind --exec -- npm start --prefix approuter

cds bind --exec -- npm start --prefix approuter

cds bind --exec '--' npm start --prefix approuter

cds bind --exec '--' npm start --prefix approuter

This works by building up a VCAP_SERVICES variable from the bindings in the chosen profiles (default: hybrid). You can run the following command to print the content of the generated VCAP_SERVICES variable:

cds bind --exec -- node -e 'console.log(process.env.VCAP_SERVICES)'

cds bind --exec -- node -e 'console.log(process.env.VCAP_SERVICES)'

cds bind --exec -- node -e 'console.log(process.env.VCAP_SERVICES)'

cds bind --exec -- node -e 'console.log(process.env.VCAP_SERVICES)'

cds bind --exec '--' node -e 'console.log(process.env.VCAP_SERVICES)'

cds bind --exec '--' node -e 'console.log(process.env.VCAP_SERVICES)'

Run CAP Java Apps with Service Bindings ​

Start your CAP Java application with the cds bind --exec command to use the service bindings.

For example:

cds bind --exec mvn spring-boot:run

cds bind --exec mvn spring-boot:run

Run with Service Bindings from a Running Cloud Application ​

Run CAP Apps Using Cloud Application Bindings ​

Instead of binding to specific cloud services, you can run your application with all service bindings of an application on the SAP BTP, Cloud Foundry environment.

For example, you can use the following syntax with bash or similar shells:

VCAP_SERVICES=$(cf env <CF-APP-NAME> | perl -0pe '/VCAP_SERVICES:(.*?)VCAP_APPLICATION:/smg; $_=$1') cds watch --profile hybrid

VCAP_SERVICES=$(cf env <CF-APP-NAME> | perl -0pe '/VCAP_SERVICES:(.*?)VCAP_APPLICATION:/smg; $_=$1') cds watch --profile hybrid

Your profile should have the kind settings to use the bound services, for example requires.db = hana.

cds bind Usage ​

By Cloud Service Only ​

The shortest way to use cds bind is to specify only the Cloud Foundry service instance name:

cds bind -2 my-hana

cds bind -2 my-hana

This implies that a service key exists with the suffix -key. In this example: my-hana-key.

You can specify a different key after a colon (":"):

cds bind -2 my-hana:my-different-key

cds bind -2 my-hana:my-different-key

With CDS Service and Kind ​

If kind or CDS service cannot be determined automatically by cds bind, you need to specify it:

cds bind credstore -2 my-credstore --kind credstore

cds bind credstore -2 my-credstore --kind credstore

You are informed with an error message if this is required.

Bind Multiple Services with One Command ​

There is a handy shortcut to bind multiple services with one command:

cds bind -2 my-hana,my-destination,my-xsuaa

cds bind -2 my-hana,my-destination,my-xsuaa

With Profile and Output File ​

By default, the bindings for the hybrid profile are stored in the .cdsrc-private.json file in your current working directory.

This can be overwritten using the --profile and --output-file options.

Execute Commands with Bindings ​

You can start arbitrary command line programs with your bindings.

The service bindings are resolved from the cloud and provided in the VCAP_SERVICES env variable to the application. So it works with every application that can consume Cloud Foundry credentials.

cds bind --exec [--] <command> <args ...>

cds bind --exec [--] <command> <args ...>

Use the double-dash (--) if your command has args starting with a dash (-) character. Otherwise the cds command line will try to parse them as their own options.

On PowerShell you need to quote the double dash (--) when an option with double dash follows, e.g.

cds bind --exec '--' somecmd --someflag --some-double-dash-parameter 42

cds bind --exec '--' somecmd --someflag --some-double-dash-parameter 42

Profiles can be set using the optional --profile parameter. By default the hybrid profile is used.

cds bind --exec --profile <profile> [--] <command> <args ...>

cds bind --exec --profile <profile> [--] <command> <args ...>

The --profile parameter must follow exec directly.

Use Cases ​

Most of the following use cases are shown for Node.js, but can be easily adapted for Java.

Destinations ​

Learn how to connect to remote services from local using SAP BTP destinations.

Authentication and Authorization using XSUAA ​

Learn how to do hybrid testing using the XSUAA service in the CAP Node.js authentication documentation.

Integration Tests ​

cds bind can be handy for testing with real cloud services in your CI/CD pipeline.

Configure your required bindings for testing and save them to your project's package.json file for your tests' profile:

cds bind -2 integration-test-hana -o package.json -p integration-test

cds bind -2 integration-test-hana -o package.json -p integration-test

No credentials are saved!

In your CI/CD pipeline you can resolve the bindings and inject them into the test commands:

# Install DK for "cds env"
npm i @sap/cds-dk --no-save

# Login
cf auth $USER $PASSWORD

## Uncomment if your service bindings have
## no "org" and "space" set (see note below)
# cf target -o $ORG -s $SPACE

# Set profile
export CDS_ENV=integration-test
# Set resolved bindings
export cds_requires="$(cds env get requires --resolve-bindings)"

# Execute test
npm run integration-test

# Install DK for "cds env"
npm i @sap/cds-dk --no-save

# Login
cf auth $USER $PASSWORD

## Uncomment if your service bindings have
## no "org" and "space" set (see note below)
# cf target -o $ORG -s $SPACE

# Set profile
export CDS_ENV=integration-test
# Set resolved bindings
export cds_requires="$(cds env get requires --resolve-bindings)"

# Execute test
npm run integration-test

With CDS_ENV, you specify the configuration profile for the test, where you previously put the service binding configuration.

cds env get requires prints the requires section of the configuration as a JSON string. By adding the --resolve-bindings option, it includes the credentials of the service bindings from the cloud. To make the credentials available for all subsequent cds commands and the tests, the requires JSON string is put into the cds_requires variable.