CAP Operator Plugin

The CAP Operator Plugin offers a simple method for generating CAP Operator resources, which are essential for deploying multi-tenant CAP Applications.

Before You Start

The CAP Operator plugin requires @sap/cds-dk: ">=8.2.1". If you've installed @sap/cds-dk globally, ensure that the installed version is 8.2.1 or higher.

Set Up the Plugin

To integrate the CAP Operator Plugin into your project, follow these steps:

1. Add the plugin package to your project as a dev dependency:

    npm add @cap-js/cap-operator-plugin -D

2. After installation, execute the following command to add the CAP Operator Helm chart to your project:

   cds add cap-operator

   

   This creates a chart folder in your directory with three files: Chart.yaml, values.schema.json, and values.yaml.

   You might notice that the templates folder is missing. This is intentional. The idea is to push only these three files into your GitHub repository. When you deploy your application, you can call cds build, and during the build, the plugin generates the final Helm chart in your project's gen directory, which includes the predefined templates folder.

   Available Options

   • --with-templates

     With this option, the plugin also adds the templates folder to the chart folder initially. This is required when applications have to modify the predefined template files to support more complex scenarios. If you use this option, you can skip the cds build step, as the chart already contains the templates folder.

     cds add cap-operator --with-templates

     

   • --with-configurable-templates

     With this option, the plugin adds a chart with configurable templates. This is required when applications need to utilize template functions in the CAP Operator resources. In this version of the chart, all the CAP Operator resource configurations are defined in templates/cap-operator-cros.yaml. If you choose this option, you can skip the cds build step since the chart already contains the templates folder.

     cds add cap-operator --with-configurable-templates

     

     If you have already added your chart and want to switch to --with-configurable-templates, you can use the plugin to convert the existing chart. For more information, see the Converting to Configurable Templates section.

   • --force

     This option allows you to overwrite the existing chart folder.

     cds add cap-operator --force

   Experimental Options

   • --with-mta && --with-mta-extensions

     Using --with-mta, the values.yaml can be prefilled with the design-time deployment information from mta.yaml.

     cds add cap-operator --with-mta <mta-yaml-file-path>

     Using --with-mta-extensions, you can also pass mta extensions. If you have multiple mta extensions, you can pass them as a comma-separated string to merge them.

     cds add cap-operator --with-mta <mta-yaml-file-path> --with-mta-extensions <mta-ext-yaml-1-file-path>,<mta-ext-yaml-2-file-path>

     

     As mentioned above, the plugin will automatically inject the templates folder into the final chart during cds build. But if you want to add the templates folder during chart folder creation, you can use --with-templates along with this option as shown below:

     cds add cap-operator --with-mta <mta-yaml-file-path> --with-mta-extensions <mta-ext-yaml-1-file-path>,<mta-ext-yaml-2-file-path> --with-templates

3. Once you've executed the command above, the basic chart folder or chart folder with templates is added to your project directory, depending on your choice.

Configure Your Chart

The generated chart/values.yaml contains two types of information:

• Design-time deployment

  • Without option --with-configurable-templates
    • serviceInstances
    • serviceBindings
    • workloads - There are two types of workloads:
      • Deployment definition
      • Job definition
    • tenantOperations
    • contentJobs
  • With option --with-configurable-templates
    • serviceInstances
    • serviceBindings
    • workloads - With this option all the workload configuations are maintained in templates/cap-operator-cros.yaml and in the values.yaml you can only define the images for the workloads.

• Runtime deployment

  • app
    • Primary - Primary application domain is used to generate a wildcard TLS certificate. In clusters managed by project "Gardener", this is (usually) a subdomain of the cluster domain
    • Secondary - Customer-specific domains to serve application endpoints (optional)
    • IstioIngressGatewayLabels - Labels used to identify the Istio ingress-gateway component and its corresponding namespace. Usually {“app”:“istio-ingressgateway”,“istio”:“ingressgateway”}
  • btp
    • GlobalAccountId - SAP BTP Global Account Identifier where services are entitled for the current application
    • Subdomain - Subdomain of the provider subaccount to which you deploy the application.
    • TenantId - Tenant ID of the provider subaccount to which you deploy the application
  • imagePullSecrets - Kubernetes secret used to pull the application docker images from a private container image registry or repository.
  • env information inside workloads

As a developer, you must fill in the design-time deployment information in the values.yaml file, which can then be pushed to your GitHub repository. The plugin auto-populates some values based on your project configuration, but verifying them and manually filling in any missing information is essential. You can refer to values.schema.json file for the structure of the values.yaml file.

Please fill the values.yaml according to the schema as it is tightly coupled to the predefined templates. You can use a YAML schema validation extension such as YAML or run the following command to validate your values.yaml file. You can ignore the errors from runtime values as they are not filled in yet.

helm lint <chart-path>

Deploy Your Application

1. You must generate the final Helm chart before deploying your application. You can do so by running cds build. During the build, the plugin generates the final Helm chart in your project's gen directory, which includes the predefined templates folder.

   

   If you've already added the templates folder during the initial plugin call using --with-templates or --with-configurable-templates option, you can skip this step as the Helm chart is already complete.

2. Up to this point, you've only filled in the design time information in the chart. But to deploy the application, you need to create a runtime-values.yaml file with all the runtime values, as mentioned in the section on configuration. You can generate the file using the plugin itself.

   The plugin requires the following information to generate the runtime-values.yaml:

   • Application name (appName) [Mandatory]
   • CAP Operator subdomain (capOperatorSubdomain) [Mandatory] - In Kyma clusters, CAP Operator subdomain defaults to cap-op. But if you're using your "Gardener" cluster, you must provide the subdomain you used to install the CAP Operator.
   • Cluster shoot domain (clusterDomain) [Mandatory] - Shoot domain of your cluster. In Kyma clusters, you can get the shoot domain by running the following command.

     kubectl get gateway -n kyma-system kyma-gateway -o jsonpath='{.spec.servers[0].hosts[0]}'

   • Global Account ID (globalAccountId) [Mandatory] - SAP BTP Global Account Identifier where services are entitled for the application.
   • Provider subdomain (providerSubdomain) [Mandatory] - Subdomain of the provider subaccount to which you deploy the application.
   • Tenant ID (tenantId) [Mandatory] - Tenant ID of the provider subaccount to which you deploy the application.
   • HANA Instance ID (hanaInstanceId) [Optional] - ID of the SAP HANA instance to which the application is deployed. It's only required if there are multiple SAP HANA instances in the subaccount.
   • Image Pull Secrets (imagePullSecret) [Optional] - Kubernetes secret used to pull the application docker images from a private container image registry or repository.

   The plugins provide two ways to generate the runtime values file:

   • Interactive Mode - This mode will ask you individually for all the runtime values. To use this mode, run the following command:

     npx cap-op-plugin generate-runtime-values

     

   • File Mode - You can provide all the required runtime values in a YAML file using this mode. To use this mode, run the following command:

     npx cap-op-plugin generate-runtime-values --with-input-yaml <input-yaml-path>

     

     Sample input yaml -

     appName: incidentapp
     capOperatorSubdomain: cap-op
     clusterDomain: abc.com
     globalAccountId: abcdef-abcd-4ef1-9263-1b6b7b6b7b6b
     providerSubdomain: provider-subdomain-1234
     tenantId: da37c8e0-74d4-abcd-b5e2-sd8f7d8f7d8f
     hanaInstanceId: 46e285d9-abcd-4c7d-8ebb-502sd8f7d8f7d
     imagePullSecret: regcred

     Similar to the interactive mode, appName, capOperatorSubdomain, clusterDomain, globalAccountId, providerSubdomain, and tenantId are mandatory fields. If they're not provided in the input YAML, the plugin throws an error. After execution, the runtime-values.yaml file is created in the chart folder of your project directory.

3. Now, you can deploy the application using the following command:

   helm upgrade -i -n <namespace> <release-name> <project-path>/gen/chart -f <project-path>/chart/runtime-values.yaml

   If you want to set the xs-security.json as a parameter in your xsuaa service instance, you can do so by setting the jsonParameters attribute on the service instance as follows:

   helm upgrade -i -n <namespace> <release-name> <project-path>/gen/chart --set-file serviceInstances.xsuaa.jsonParameters=<project-path>/xs-security.json -f <project-path>/chart/runtime-values.yaml

Converting to Configurable Templates Chart

If you've already added the basic chart folder and want to switch to configurable templates chart, you can use the plugin to convert the chart. To do so, run the following command:

npx cap-op-plugin convert-to-configurable-template-chart

If you want to convert the existing runtime-values.yaml as well to the new format, you can do so by passing the runtime-values.yaml path via the --with-runtime-yaml option:

npx cap-op-plugin convert-to-configurable-template-chart --with-runtime-yaml <project-path>/chart/runtime-values.yaml

Example

As a reference, check out the CAP Operator Helm chart in the sample incident app. Also, take a look at the corresponding runtime-values.yaml file.

❗Things to Note

• If you're adding the basic chart folder using the cds add cap-operator command, don't modify the values.schema.json file. The templates injected automatically during cds build are tightly coupled with the structure in values.schema.json. If schema changes are needed, use the option --with-templates to add the templates folder and adjust them accordingly.

• When defining environment variables for workloads in the values.yaml file, it's crucial to mirror these definitions in the runtime-values.yaml file. This ensures consistency and avoids potential conflicts, as Helm doesn't merge arrays. If you're introducing new environment variables in runtime-values.yaml for a workload, remember to include existing variables from values.yaml to maintain coherence. If you use the plugin to generate the runtime-values.yaml, the environment variables are automatically copied from values.yaml.

Contributing

This project is open to feature requests/suggestions, bug reports etc. via GitHub issues. Contribution and feedback are encouraged and always welcome. For more information about how to contribute, the project structure, as well as additional contribution information, see our Contribution Guidelines.

Code of Conduct

We as members, contributors, and leaders pledge to make participation in our community a harassment-free experience for everyone. By participating in this project, you agree to abide by its Code of Conduct at all times.

Licensing

Copyright 2024 SAP SE or an SAP affiliate company and cap-operator-plugin contributors. Please see our LICENSE for copyright and license information. Detailed information including third-party components and their licensing/copyright information is available via the REUSE tool.