Templates

Overview

Jobs and Prow configuration are generated from templates. The templates directory has the following structure:

• templates which is the subdirectory with all template files that supply the definition of Prow jobs used in Kyma.
• config.yaml which is the configuration file that describes jobs that the Render Templates tool should generate using job definitions from templates.

The template list includes:

• branchprotector-config.yaml that defines configuration for branch protection. Provide any changes related to branch protection in that file.
• compass-integration.yaml that defines presubmit and postsubmit integration jobs which build Kyma to check its compatibility with the Compass component.
• component.yaml that defines component jobs with specified buildpacks.
• generic-component.yaml that provides a new way of creating component jobs. Instead of a predefined buildpack, it uses a generic bootstrap that contains Makefile and Docker but no component-specific dependencies.
• kyma-artifacts.yaml that serves to create release artifacts.
• kyma-github-release.yaml that is used for creating the GitHub release after merging the release branch to the master branch.
• kyma-installer.yaml that is used for building the Installer during the release.
• kyma-integration.yaml that defines a set of presubmit and postsubmit integration jobs that build Kyma on clusters to verify if the introduced changes do not affect the existing Kyma components.
• kyma-release-candidate.yaml that is used for building the release cluster for testing purposes.
• prow-config.yaml that serves to create the main Prow configuration without job definitions.
• releases.go.tmpl that contains a set of functions for the release which provide the list of currently supported releases and all supported Kyma release branches.

Jobs and Prow configurations have unit tests that are located here.

Configuration file

The config.yaml file has two keys:

• global with a map of values available for all templates
• templates with a list of files to generate

The config.yaml serves as the input file for the Render Templates that generates the jobs based on the file definition and templates which it specifies. The config.yaml file defines the names of the output file, their location, and configuration referred to in values.

See the example of console-backend-service in which the generic-component.yaml template is used to create the component and test-related YAML files using values defined by the kyma_generic_component parameter.

kyma_generic_component: &kyma_generic_component
  repository: github.com/kyma-project/kyma
  pushRepository: kyma
  bootstrapTag: v20181204-a6e79be
  additionalRunIfChanged:
    - ^scripts/

templates:
  - from: templates/generic-component.yaml
    render:
      - to: ../prow/jobs/kyma/components/console-backend-service/console-backend-service-generic.yaml
        values:
          <<: *kyma_generic_component
          path: components/console-backend-service
          since: "1.6"
      - to: ../prow/jobs/kyma/tests/console-backend-service/console-backend-service-tests-generic.yaml
        values:
          <<: *kyma_generic_component
          path: tests/console-backend-service
          since: "1.6"

Component templates

A template receives two objects as input:

• Values which contains all the values specified under values in the config.yaml file.
• Global which contains values specified under global in the config.yaml file.

There are two templates that contain the default configuration for the Prow component jobs, component.yaml and generic-component.yaml. The recommended template is generic-component.yaml that is the new version of the component.yaml template and uses a generic bootstrap to build components, instead of various buildpacks.

See the description of values used by both component templates:

Name	Required	Component template(s)	Description
additionalRunIfChanged	No	generic-component.yaml	Provides a list of regexps for Prow to watch in addition to path. Prow runs the job if it notices any changes in the specified files or folders. The default value is [].
bootstrapTag	Yes	generic-component.yaml	Provides the tag of the bootstrap image to use.
buildpack	Yes	component.yaml	Specifies the buildpack version used to build the component.
env	No	component.yaml	Specifies the environment variable that turns on Go modules required to build Kubebuilder v2.
noRelease	No	component.yaml	Specifies that this component does not require a release job.
optional	No	Both	Defines if this job is obligatory or optional on pull requests. Set it to true when you add a new component and remove it after the whole CI pipeline for the component is in place.
patchReleases	No	component.yaml	A list of releases that patch the given component version.
path	Yes	Both	Specifies the location of the component in the repository, such as components/console-backend-service.
presets.build	Yes	component.yaml	The name of the Preset for building the component on the master branch. For example, set to build to use the preset-build-master Preset.
presets.pushRepository	Yes	component.yaml	Provides the suffix of the preset-docker-push- label to define the GCR image location, such as kyma.
pushRepository	Yes	generic-component.yaml	Provides the suffix of the preset-docker-push- label to define the GCR image location, such as kyma.
ReleaseBranchPattern	No	generic-component.yaml	Defines the prefix pattern for the release branch for which Prow should run the release job. The default value is ^release-{supported-releases}-{component-dir-name}$.
repository	Yes	Both	Specifies the component's GitHub repository address, such as github.com/kyma-project/kyma.
resources.memory	No	Both	Specifies the memory assigned to the job container. The default value is 1.5Gi.
resources.cpu	No	Both	Specifies the CPU assigned to the job container. The default value is 0.8.
since	Yes	Both	Specifies the release from which this component version applies.
until	Yes	Both	Specifies the release till which this component version applies.
watch	No	component.yaml	Provides a list of regexps for Prow to watch in addition to path. Prow runs the job if it notices any changes in the specified files or folders.

All the functions from the sprig library are available in the templates. It is the same library that is used by Helm, so if you know Helm, you are already familiar with them. Also, a few additional functions are available:

• releaseMatches {release} {since} {until} returns a boolean value indicating whether release fits in the range. Use nil to remove one of the bounds. For example, releaseMatches {{ $rel }} '1.2' '1.5' checks if the release $rel is not earlier than 1.2 and not later than 1.5.
• matchingReleases {all-releases} {since} {until} returns a list of releases filtered to only those that fit in the range.