Merge branch 'feature/gb/add-serverless-cicd-template' into 'master'

Simplify CI/CD configuration on serverless projects

Closes #57405

See merge request gitlab-org/gitlab-ce!25523

changelogs/unreleased/feature-gb-add-serverless-cicd-template.yml

+---
+title: Simplify CI/CD configuration on serverless projects
+merge_request: 25523
+author:
+type: added

doc/user/project/clusters/serverless/index.md

@@ -114,28 +114,35 @@ Follow these steps to deploy a function using the Node.js runtime to your Knativ
     - Public, continue to the next step.
     - Private, you will need to [create a GitLab deploy token](../../deploy_tokens/index.md#creating-a-deploy-token) with `gitlab-deploy-token` as the name and the `read_registry` scope.
 
-1. `.gitlab-ci.yml`: This template allows to define the stage, environment, and
-   image to be used for your functions. It must be included at the root of your repository:
+1. `.gitlab-ci.yml`: this defines a pipeline used to deploy your functions.
+   It must be included at the root of your repository:
 
    ```yaml
-   stages:
-     - deploy
+   include:
+     template: Serverless.gitlab-ci.yml
 
    functions:
-     stage: deploy
-     environment: test
-     image: gcr.io/triggermesh/tm:v0.0.9
-     script:
-      - tm -n "$KUBE_NAMESPACE" set registry-auth gitlab-registry --registry "$CI_REGISTRY" --username "$CI_REGISTRY_USER" --password "$CI_JOB_TOKEN" --push
-      - tm -n "$KUBE_NAMESPACE" set registry-auth gitlab-registry --registry "$CI_REGISTRY" --username "$CI_DEPLOY_USER" --password "$CI_DEPLOY_PASSWORD" --pull
-      - tm -n "$KUBE_NAMESPACE" deploy --wait
-
+     extends: .serverless:deploy:functions
+     environment: production
    ```
 
-    The `gitlab-ci.yml` template creates a `Deploy` stage with a `functions` job that invokes the `tm` CLI with the required parameters.
+    This `.gitlab-ci.yml` creates a `functions` job that invokes some
+    predefined commands to deploy your functions to your cluster.
+
+    `Serverless.gitlab-ci.yml` is a template that allows customization.
+    You can either import it with `include` parameter and use `extends` to
+    customize your jobs, or you can inline the entire template by choosing it
+    from **Apply a template** dropdown when editing the `.gitlab-ci.yml` file through
+    the user interface.
+
+2. `serverless.yml`: this file contains the metadata for your functions,
+   such as name, runtime, and environment.
 
-2. `serverless.yml`: This file contains the metadata for your functions,
-   such as name, runtime, and environment. It must be included at the root of your repository. The following is a sample `echo` function which shows the required structure for the file. You can find the relevant files for this project in the [functions example project](https://gitlab.com/knative-examples/functions).
+   It must be included at the root of your repository.
+   The following is a sample `echo` function which shows the required structure
+   for the file.
+
+   You can find the relevant files for this project in the [functions example project](https://gitlab.com/knative-examples/functions).
 
    ```yaml
    service: my-functions
@@ -234,32 +241,22 @@ Add the following `.gitlab-ci.yml` to the root of your repository
 (you may skip this step if you've previously cloned the sample [Knative Ruby App](https://gitlab.com/knative-examples/knative-ruby-app) mentioned above):
 
 ```yaml
-stages:
-  - build
-  - deploy
+include:
+  template: Serverless.gitlab-ci.yml
 
 build:
-  stage: build
-  image:
-    name: gcr.io/kaniko-project/executor:debug
-    entrypoint: [""]
-  only:
-    - master
-  script:
-    - echo "{\"auths\":{\"$CI_REGISTRY\":{\"username\":\"$CI_REGISTRY_USER\",\"password\":\"$CI_REGISTRY_PASSWORD\"}}}" > /kaniko/.docker/config.json
-    - /kaniko/executor --context $CI_PROJECT_DIR --dockerfile $CI_PROJECT_DIR/Dockerfile --destination $CI_REGISTRY_IMAGE
+  extends: .serverless:build:image
 
 deploy:
-  stage: deploy
-  image: gcr.io/triggermesh/tm@sha256:e3ee74db94d215bd297738d93577481f3e4db38013326c90d57f873df7ab41d5
-  only:
-    - master
-  environment: production
-  script:
-    - echo "$CI_REGISTRY_IMAGE"
-    - tm -n "$KUBE_NAMESPACE" --config "$KUBECONFIG" deploy service "$CI_PROJECT_NAME" --from-image "$CI_REGISTRY_IMAGE" --wait
+  extends: .serverless:deploy:image
 ```
 
+`Serverless.gitlab-ci.yml` is a template that allows customization.
+You can either import it with `include` parameter and use `extends` to
+customize your jobs, or you can inline the entire template by choosing it
+from **Apply a template** dropdown when editing the `.gitlab-ci.yml` file through
+the user interface.
+
 ### Deploy the application with Knative
 
 With all the pieces in place, the next time a CI pipeline runs, the Knative application will be deployed. Navigate to

lib/gitlab/ci/templates/Serverless.gitlab-ci.yml

+# GitLab Serverless template
+
+image: alpine:latest
+
+stages:
+  - build
+  - deploy
+
+.serverless:build:image:
+  variables:
+    DOCKERFILE: "Dockerfile"
+  stage: build
+  image:
+    name: gcr.io/kaniko-project/executor:debug
+    entrypoint: [""]
+  only:
+    refs:
+      - master
+  script:
+    - echo "{\"auths\":{\"$CI_REGISTRY\":{\"username\":\"$CI_REGISTRY_USER\",\"password\":\"$CI_REGISTRY_PASSWORD\"}}}" > /kaniko/.docker/config.json
+    - /kaniko/executor --context $CI_PROJECT_DIR --dockerfile $CI_PROJECT_DIR/$DOCKERFILE --destination $CI_REGISTRY_IMAGE
+
+.serverless:deploy:image:
+  stage: deploy
+  image: gcr.io/triggermesh/tm@sha256:e3ee74db94d215bd297738d93577481f3e4db38013326c90d57f873df7ab41d5
+  only:
+    refs:
+      - master
+  environment: development
+  script:
+    - echo "$CI_REGISTRY_IMAGE"
+    - tm -n "$KUBE_NAMESPACE" --config "$KUBECONFIG" deploy service "$CI_PROJECT_NAME" --from-image "$CI_REGISTRY_IMAGE" --wait
+
+.serverless:deploy:functions:
+  stage: deploy
+  environment: development
+  image: gcr.io/triggermesh/tm:v0.0.9
+  script:
+   - tm -n "$KUBE_NAMESPACE" set registry-auth gitlab-registry --registry "$CI_REGISTRY" --username "$CI_REGISTRY_USER" --password "$CI_JOB_TOKEN" --push
+   - tm -n "$KUBE_NAMESPACE" set registry-auth gitlab-registry --registry "$CI_REGISTRY" --username "$CI_DEPLOY_USER" --password "$CI_DEPLOY_PASSWORD" --pull
+   - tm -n "$KUBE_NAMESPACE" deploy --wait

spec/lib/gitlab/ci/templates/templates_spec.rb

@@ -3,9 +3,40 @@
 require 'spec_helper'
 
 describe "CI YML Templates" do
-  Gitlab::Template::GitlabCiYmlTemplate.all.each do |template|
-    it "#{template.name} should be valid" do
-      expect { Gitlab::Ci::YamlProcessor.new(template.content) }.not_to raise_error
+  ABSTRACT_TEMPLATES = %w[Serverless].freeze
+
+  def self.concrete_templates
+    Gitlab::Template::GitlabCiYmlTemplate.all.reject do |template|
+      ABSTRACT_TEMPLATES.include?(template.name)
+    end
+  end
+
+  def self.abstract_templates
+    Gitlab::Template::GitlabCiYmlTemplate.all.select do |template|
+      ABSTRACT_TEMPLATES.include?(template.name)
+    end
+  end
+
+  describe 'concrete templates with CI/CD jobs' do
+    concrete_templates.each do |template|
+      it "#{template.name} template should be valid" do
+        expect { Gitlab::Ci::YamlProcessor.new(template.content) }
+          .not_to raise_error
+      end
+    end
+  end
+
+  describe 'abstract templates without concrete jobs defined' do
+    abstract_templates.each do |template|
+      it "#{template.name} template should be valid after being implemented" do
+        content = template.content + <<~EOS
+          concrete_build_implemented_by_a_user:
+            stage: build
+            script: do something
+        EOS
+
+        expect { Gitlab::Ci::YamlProcessor.new(content) }.not_to raise_error
+      end
     end
   end
 end