GitLab CI Cloud Service

Group 3

Service Overview

GitLab CE

• GitLab Commercial Edition
• Open source (free).
• Everyone can host on his server.
• Has similar user experience to GitHub.
• User can own unlimited public/private repositaries.

GitLab CI

• GitLab Continuous Integration
• This feature is part of GitLab CE.
• Automatically run builds when a commit is pushed to GitLab.
• User shell configure the way to make builds in .gitlab-ci.yml, which is placed under the root of the repositary.
• GitLab CI requires a runner server to run builds.

Architecture

Net04_ext

Gitlab_subnet

Gitlab_Server

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Provide GitLab service:

• Host git repositaries.

Runner_Server

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As a shared runner for “Gitlab_Server”

• Run builds for all configured repositaries when a commit is pushed to “Gitlab_Server”.

Associate floating IP

router

Register a runner to Gitlab_Server.

• With a registration token.

Steps for the Stack Creation

Gitlab_Server

Runner_Server

• Create network environment.

(The order is automatically handled by hidden dependency)

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2. Launch instance “Gitlab_Server”.

(Wait with a wait condition for retrieving a registration token)

3. Launch instance “Runner_Server”

(Register to Gitlab_Server)

Estimated Time for Stack Creation

• About 8 minutes for GitLab to ready.
• Accessiable on the given floating IP.
• ex: http://140.113.240.8
• User can register accounts, create repositaries, and make git push/pull…
• About 15 minutes for GitLab CI to serve.
• Commits pushed to GitLab_Server will trigger builds according to the configuration in .gitlab-ci.yml.

The Implementation

The Heat Template (YAML)

1. Parameters

a. root_passwd,key,image,flavor,network,dns…

2. Resources

a. Server1/Server2

b. port

c. user_data

3. Outputs

a. Private_key

User_data for Instance “Gitlab_Server”

• Install GitLab.
• Following the instruction on the official website.
• Configure GitLab.
• Setting the external URL, the floating IP associated to the instance, for GitLab.
• Retrieve the registration token.
• Set root’s password for GitLab.
• Clear the expiration and make the service ready.
• Notify the wait condition
• along with the registration token.

User_data for Instance “Runner_Server”

• Install “gitlab-ci-multi-runner”.
• Following the official instruction.

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• Register the runner to “Gitlab_Server”.
• providing
• URL (the floating IP associated to Gitlab_Server)
• Registration token

Difficulties Encountered (1)

• Registration token is not stored in any file, so there is no way to retrieve it execpt for browsing the website.
• Modify the source code of GitLab. (with sed)
• Starting processes of GitLab detach immediately after the command is made, so it is unaware of when these processes will complete.
• Use a FIFO to wait for these processes finishing.

Difficulties Encountered (2)

• The registration process on Runner_Server must start after the Gitlab_Server can serve.
• Use OS::Heat::WaitCondition and OS::Heat::WaitConditionHandle
• “apt-get install” ask questions interacitively, so shellscript may be blocked.
• Use “debconf-set-selections” to answer these questions before executing “apt-get”.

Demo