Generate CHANGELOG during release promotion

Closes gh-331

Author: bclozel

ci/pipeline.yml

@@ -54,6 +54,20 @@ resources:
     username: ((artifactory-username))
     password: ((artifactory-password))
     build_name: ((build-name))
+- name: github-release
+  type: registry-image
+  source:
+    repository: concourse/github-release-resource
+    tag: 1.5.5
+- name: github-pre-release
+  type: github-release
+  icon: briefcase-download-outline
+  source:
+    owner: spring-projects
+    repository: spring-graphql
+    access_token: ((github-ci-release-token))
+    pre_release: true
+    release: false
 
 jobs:
 - name: build-ci-images
@@ -144,6 +158,19 @@ jobs:
       params:
         RELEASE_TYPE: M
         <<: *artifactory-task-params
+    - task: generate-changelog
+      file: git-repo/ci/tasks/generate-changelog.yml
+      params:
+        RELEASE_TYPE: M
+        GITHUB_USERNAME: ((github-username))
+        GITHUB_TOKEN: ((github-ci-release-token))
+      vars:
+        <<: *registry-mirror-vars
+    - put: github-pre-release
+      params:
+        name: generated-changelog/tag
+        tag: generated-changelog/tag
+        body: generated-changelog/changelog.md
 - name: stage-rc
   serial: true
   plan:
@@ -179,8 +206,21 @@ jobs:
       image: ci-image
       file: git-repo/ci/tasks/promote-version.yml
       params:
-        RELEASE_TYPE: rc
+        RELEASE_TYPE: RC
         <<: *artifactory-task-params
+    - task: generate-changelog
+      file: git-repo/ci/tasks/generate-changelog.yml
+      params:
+        RELEASE_TYPE: RC
+        GITHUB_USERNAME: ((github-username))
+        GITHUB_TOKEN: ((github-ci-release-token))
+      vars:
+        <<: *registry-mirror-vars
+    - put: github-pre-release
+      params:
+        name: generated-changelog/tag
+        tag: generated-changelog/tag
+        body: generated-changelog/changelog.md
 
 groups:
 - name: "builds"

ci/scripts/generate-changelog.sh

@@ -9,4 +9,4 @@ java -jar /github-changelog-generator.jar \
   ${version} generated-changelog/changelog.md
 
 echo ${version} > generated-changelog/version
-echo v${version} > generated-changelog/tag
+echo ${version} > generated-changelog/tag

ci/tasks/generate-changelog.yml

@@ -4,12 +4,16 @@ image_resource:
   type: registry-image
   source:
     repository: springio/github-changelog-generator
-    tag: '0.0.6'
+    tag: '0.0.7'
+    registry_mirror:
+      host: ((registry-mirror-host))
+      username: ((registry-mirror-username))
+      password: ((registry-mirror-password))
 inputs:
-- name: git-repo
-- name: artifactory-repo
+  - name: git-repo
+  - name: artifactory-repo
 outputs:
-- name: generated-changelog
+  - name: generated-changelog
 params:
   GITHUB_ORGANIZATION:
   GITHUB_REPO: