gaplib

GitHub Actions on Power and Z OCI and LXD Image Build

• gaplib
  • What is it
  • Building
    • LXD Image used by Actions Runner
      • Pre-reqs
      • Running Build
    • OCI Image used as Self-Hosted Action Runner
      • Pre-reqs
      • Building Images
  • Using
    • LXD-based
    • Self-Hosted
      • Configuring
        • Sample Build
      • Running
        • Sample Run

What is it

Simple automation pipeline to build:

1. LXD images for custom github actions runner whenever actions/runner creates a new release.
2. OCI images for a self-hosted github actions runner

Building

Instructions for building both the LXD-based and self-hosted actions runners.

LXD Image used by Actions Runner

Use these instructions to build the component required by the github-hosted actions runner.

Pre-reqs

1. lxd

• Install lxd either via snap snap install lxd --classic or, under Ubuntu, as package in the repo
• Initialize lxd via lxd init and answer the prompts according to your preferences. For example, create a file lxd-preseed.yaml containing:

  config: {}
  cluster: null
  networks:
  - config:
      ipv4.address: auto
      ipv6.address: auto
    description: "gaplib network"
    name: lxdbr0
    type: ""
  storage_pools:
  - config: {}
    description: "gaplib storage pool"
    name: default
    driver: dir
  profiles:
  - config: {}
    description: "gaplib"
    devices:
      eth0:
        name: eth0
        nictype: bridged
        parent: lxdbr0
        type: nic
      root:
        path: /
        pool: default
        type: disk
    name: default
  

  Run the command lxd init --preseed <lxd-preseed.yaml

Running Build

To build the github actions execute the setup-build-env.sh script

OCI Image used as Self-Hosted Action Runner

A self-hosted runner is a system that you deploy and manage to execute jobs from GitHub Actions on GitHub.com.

See the github documentation on self-hosted runners. In particular:

• Adding a self-hosted runner
• Using self-hosted runners
• Hardening your self-hosted runner

Pre-reqs

1. docker or podman

Building Images

Run ./build-selfhosted.sh [-b <buildtool>] [distro ...]

Where

• -b <buildtool> defaults to whichever out of podman or docker it finds. You may override by specifying either of these tools.
• [distro ...] is either ubunutu, almalinux, or opensuse. If nothing specified then all are built

Using

For both modes of running actions runners, there may be firewall changes required to allow github to communicate with the runner. For example, if the LXD-based system is listening on port 5000 then on a RHEL-like system:

firewall-cmd --add-port=5000/tcp

Similarly, if you have one or more self-hosted actions runners then each may be defined on github to connect on a different port which is then mapped by the OCI runtime to port 443. Each of those external ports need to firewall configuration.

LXD-based

Documentation coming soon

Self-Hosted

The OCI image is ephemeral and requires configuration each time it is used. To create an application-specific OCI image then you use the image created earlier and pre-configure it so each time it is started it is ready to perform the actions for the specific repository.

Configuring

Assume we wish to provide actions for the pleia2/python-test repository. We would create a image using the following dockerfile where the TOKEN argument is generated when you add the self-hosted runner on github.

Sample file Dockerfile.test

FROM    localhost/runner:ubunutu

ARG     REPO TOKEN

RUN     /opt/runner/config.sh --url ${REPO} --token ${TOKEN}

CMD     /opt/runner/run.sh

To build:

• Docker: docker build --build-arg=TOKEN=xxxxxx --build-arg=REPO=yyyyy --squash -f Dockerfile.test --tag runner:test .
• Podman: podman build i--build-arg=TOKEN=xxxxx --build-arg=REPO=yyyyy --squash-all -f Dockerfile.test --tag runner:test --from localhost/runner:ubuntu .

Sample Build

> podman build -f Dockerfile.test --build-arg TOKEN=XXXXXXXXXXXXXXXXXXXXXXXXXXXXX --build-arg REPO=https://github.com/nealef/xx-xxxx --tag runner:test --from localhost/runner:ubuntu --squash-all .
STEP 1/4: FROM localhost/runner:ubuntu
STEP 2/4: ARG     REPO TOKEN
STEP 3/4: RUN     /opt/runner/config.sh --url ${REPO} --token ${TOKEN}

--------------------------------------------------------------------------------
|        ____ _ _   _   _       _          _        _   _                      |
|       / ___(_) |_| | | |_   _| |__      / \   ___| |_(_) ___  _ __  ___      |
|      | |  _| | __| |_| | | | | '_ \    / _ \ / __| __| |/ _ \| '_ \/ __|     |
|      | |_| | | |_|  _  | |_| | |_) |  / ___ \ (__| |_| | (_) | | | \__ \     |
|       \____|_|\__|_| |_|\__,_|_.__/  /_/   \_\___|\__|_|\___/|_| |_|___/     |
|                                                                              |
|                       Self-hosted runner registration                        |
|                                                                              |
--------------------------------------------------------------------------------

# Authentication


√ Connected to GitHub

# Runner Registration

Enter the name of the runner group to add this runner to: [press Enter for Default]
Enter the name of runner: [press Enter for f87a23ac8222]
This runner will have the following labels: 'self-hosted', 'Linux', 'S390X'
Enter any additional labels (ex. label-1,label-2): [press Enter to skip]
√ Runner successfully added
√ Runner connection is good

# Runner settings

Enter name of work folder: [press Enter for _work]
√ Settings Saved.

STEP 4/4: CMD     /opt/runner/run.sh
COMMIT runner:test
Getting image source signatures
Copying blob e7313806e8a2 done
Copying config 7aca7e9e0e done
Writing manifest to image destination
--> 7aca7e9e0e3a
[Warning] one or more build args were not consumed: [TOKEN]
Successfully tagged localhost/runner:test
7aca7e9e0e3a747fd4aef471a787e27e7464187c691f7a855f359dd6e7127d30

> podman images
REPOSITORY                                 TAG                     IMAGE ID      CREATED             SIZE
localhost/runner                           test                    7aca7e9e0e3a  About a minute ago  1.54 GB

Running

• Docker: docker run runner:test
• Podman: podman run runner:test

Sample Run

Using the file Makefile.yml in the .gitub/workflow directory of the repository containing:

name: Makefile CI

on:
  push:
    branches: [ "main" ]
  pull_request:
    branches: [ "main" ]

jobs:
  build:

    runs-on: self-hosted

    steps:
    - uses: actions/checkout@v3

    - name: Install dependencies
      run: sudo apt-get install -y golang-go

    - name: Build
      run: GOPATH=/home/ubuntu/go GOCACHE=/tmp/go make

Start the runner:

> podman run --rm -it runner:test

√ Connected to GitHub

Current runner version: '2.312.0'
2024-01-31 01:56:33Z: Listening for Jobs
2024-01-31 01:56:40Z: Running job: build
2024-01-31 01:57:39Z: Job build completed with result: Succeeded

The github actions page for that repo will show something like this: