Add a manual job to trigger package build in omnibus

.gitlab-ci.yml

@@ -23,6 +23,7 @@ before_script:
   - source scripts/prepare_build.sh
 
 stages:
+- build
 - prepare
 - test
 - post-test
@@ -137,6 +138,28 @@ stages:
   <<: *only-master-and-ee-or-mysql
   <<: *except-docs
 
+# Trigger a package build on omnibus-gitlab repository
+
+build-package:
+  services: []
+  variables:
+    SETUP_DB: "false"
+    USE_BUNDLE_INSTALL: "false"
+  stage: build
+  when: manual
+  script:
+    # If no branch in omnibus is specified, trigger pipeline against master
+    - if [ -z "$OMNIBUS_BRANCH" ] ; then export OMNIBUS_BRANCH=master ;fi
+    - echo "token=${BUILD_TRIGGER_TOKEN}" > version_details
+    - echo "ref=${OMNIBUS_BRANCH}" >> version_details
+    - echo "variables[ALTERNATIVE_SOURCES]=true" >> version_details
+    - echo "variables[GITLAB_VERSION]=${CI_COMMIT_SHA}" >> version_details
+    # Collect version details of all components
+    - for f in *_VERSION; do echo "variables[$f]=$(cat $f)" >> version_details; done
+    # Trigger the API and pass values collected above as parameters to it
+    - cat version_details | tr '\n' '&' | curl -X POST https://gitlab.com/api/v4/projects/20699/trigger/pipeline --data-binary @-
+    - rm version_details
+
 # Prepare and merge knapsack tests
 knapsack:
   <<: *knapsack-state

doc/development/README.md

@@ -41,6 +41,7 @@
 - [Shell commands](shell_commands.md) in the GitLab codebase
 - [Sidekiq debugging](sidekiq_debugging.md)
 - [Object state models](object_state_models.md)
+- [Building a package for testing purposes](build_test_package.md)
 
 ## Databases
 

doc/development/build_test_package.md

+# Building a package for testing
+
+While developing a new feature or modifying an existing one, it is helpful if an
+installable package (or a docker image) containing those changes is available
+for testing. For this very purpose, a manual job is provided in the GitLab CI/CD
+pipeline that can be used to trigger a pipeline in the omnibus-gitlab repository
+that will create
+1. A deb package for Ubuntu 16.04, available as a build artifact, and
+2. A docker image, which is pushed to [Omnibus GitLab's container 
+registry](https://gitlab.com/gitlab-org/omnibus-gitlab/container_registry)
+(images titled `gitlab-ce` and `gitlab-ee` respectively and image tag is the
+commit which triggered the pipeline).
+
+When you push a commit to either the gitlab-ce or gitlab-ee project, the
+pipeline for that commit will have a `build-package` manual action you can
+trigger.
+
+## Specifying versions of components
+
+If you want to create a package from a specific branch, commit or tag of any of
+the GitLab components (like GitLab Workhorse, Gitaly, GitLab Pages, etc.), you
+can specify the branch name, commit sha or tag in the component's respective
+`*_VERSION` file. For example, if you want to build a package that uses the
+branch `0-1-stable`, modify the content of `GITALY_SERVER_VERSION` to
+`0-1-stable` and push the commit. This will create a manual job that can be
+used to trigger the build.
+
+## Specifying the branch in omnibus-gitlab repository
+
+In scenarios where a configuration change is to be introduced and omnibus-gitlab
+repository already has the necessary changes in a specific branch, you can build
+a package against that branch through an environment variable named
+`OMNIBUS_BRANCH`. To do this, specify that environment variable with the name of
+the branch as value in `.gitlab-ci.yml` and push a commit. This will create a
+manual job that can be used to trigger the build.