pi-jenkins-ssh-agent

A docker ssh agent for Jenkins that runs on Raspberry Pis (ARM). The ssh agent's docker image is based on Jenkin's docker-ssh-slave.

Docker Images

Images are hosted on Docker Hub and can be used with the Jenkins Docker Plugin.

https://hub.docker.com/r/ottenwbe/armv7-jenkins-ssh-agent

Repo Structure

.
├── CI                      // Files required by the Jenkins pipeline 
│   ├── build-config.yaml   // Build configuration parameters 
│   ├── buildConfig.groovy  // Helper scripts 
│   ├── goss.yaml           // GOSS tests for the docker image
│   └── Jenkinsfile         // The pipeline
├── Dockerfile              // Docker ssh agent's (armv7) Dockerfile
├── LICENSE
├── README.md
└── setup-sshd              

Build

Build locally

The ssh agent's docker image can be built locally on an arm system, e.g., on a Raspberry Pi. Note, the BASE_IMAGE_TAG build arg has to be set to specify the version of the underlying Raspbian (balenalib/rpi-raspbian).

git clone https://github.com/ottenwbe/pi-jenkins-ssh-agent.git
cd pi-jenkins-ssh-agent
docker build --build-arg BASE_IMAGE_TAG=stretch-20190524 -t rpi-jenkins-ssh-agent:test .

Build with Jenkins

The ssh agent can be built with a Jenkins pipeline.

Prerequisites

• Jenkins (up and running)
• Jenkins Plugins:
  • Docker Plugin.
  • Pipeline Utility Steps
  • SSH Agent Plugin
• The SMTP server is configured to send EMails. (see, Manage Jenkins > Configure System > Extended E-mail Notification)
• The docker plugin is configured to spin up an existing version of the docker ssh agent for all builds labeled with sshagent on an arm system (e.g., a raspberry pi). (see, Manage Jenkins > Configure System > Docker)

Configure Jenkins pipeline

1. Create a Pipeline or Multibranch Pipeline project
   1. Select this repository or a fork of it under SCM
   2. Select 'CI/Jenkinsfile' as Script Path
2. Configure all required credentials ('dockerhub, 'github-bot') in the credentials store
3. Trigger the pipeline to build the docker image

Configure Build

The build is configured through the build-config.yaml file. This allows the Jenkins pipeline to automatically update the configuration.

baseImageTag: // stores the latest base image tag that was used to build the ssh agent image (Note: maintained by the Jenkins pipeline)
baseImageURL: // reference to the tags of the base image; used to find newer base image tags
pattern: // a pattern that describes the desired base image tag, e.g., stretch-\d{8} to only use stretch images
version: // the ssh agent's docker image is tagged as <major_version>.<minor_version>.<date of the build>
  major: <major_version>
  minor: <minor_version> // automatically incremented once the base image tag is updated to a newer tag  
maintainer: // maintainer label for the docker image
DockerOrg: // the docker organization to which the built image is pushed
app: jenkins-ssh-agent // <arch>-<app>: name of the docker image (armv7-jenkins-ssh-agent) 
arch: armv7
os: linux
releaseBranch: // only publish images and changes from this branch
forceBuild: // will force a build although no newer base image is found