Building a CI for Golang test

I built a CI with Jenkins for Golang test. We run go test on a Docker container and even run Jenkins on a Docker container.

Directories

app
├── docker
│   ├── dockerfiles # Dockerfiles for unit test
│   └── test
│       ├── init-db.sh # This initializes DB before testing
│       └── test.sh # Testing script
└── Jenkinsfile # The configuration for Jenkins pipeline

Environment of CI

Our Jenkins server uses an EC2 instance of t2.large, and the server runs on Docker container, and even a unit test run on Docker container on the container Jenkins runs with /var/run/docker.sock.

Jenkins loads Jenkinsfile and then execute it on the Jenkins pipeline.

How to build an execution environment

Create an AWS EC2 instance

We prepare the instance of EC2 installed Docker CE. Please see Get Docker CE for CentOS installation guide.

Create a Docker image for golang unit test

Jenkins

Dockerfile

FROM jenkins/jenkins:lts

# Switch to root user
USER root

# Install Docker
RUN apt-get update
RUN apt-get install -y \
     apt-transport-https \
     ca-certificates \
     curl \
     gnupg2 \
     software-properties-common

RUN curl -fsSL https://download.docker.com/linux/debian/gpg | apt-key add -
RUN add-apt-repository \
   "deb [arch=amd64] https://download.docker.com/linux/debian \
   $(lsb_release -cs) \
   stable"
RUN apt-get update
RUN apt-get install -y docker-ce
RUN echo "jenkins ALL=(ALL) NOPASSWD:ALL" >> /etc/sudoers

# Switch back to jenkins user
USER jenkins

# Set system timezone JST

ENV TZ Asia/Tokyo

Run on a Jenkins host.

$ docker build --rm --tag jenkins-docker:latest .

Golang

Dockerfile

FROM circleci/golang:1.9

# Install goose
RUN curl https://glide.sh/get | sh
RUN go get bitbucket.org/liamstask/goose/cmd/goose

# Set system timezone JST
ENV TZ Asia/Tokyo

Run on our Jenkins host.

$ docker build --rm --tag golang:latest .

Launch Jenkins

$ sudo docker run --env JAVA_OPTS=-Dorg.apache.commons.jelly.tags.fmt.timeZone=Asia/Tokyo -v /var/run/docker.sock:/var/run/docker.sock --name jenkins -d -p 80:8080 -p 50000:50000 -v jenkins_home:/var/jenkins_home jenkins-docker:latest

-v /var/run/docker.sock:/var/run/docker.sock is used to manipulate host's Docker because we want to launch containers on host-side.

-v jenkins_home:/var/jenkins_home is used to store everything of our Jenkins configurations and build results on our host's filesystem. If you move your Jenkins to another host or backup your Jenkins data, read this page.

Add a job to Jenkins

We need to enable Jenkins to hook Pull Requests when some developer does it.

Below settings on Jenkins.

Add a credential of GitHub enterprise

Because we use GitHub enterprise our development.

Credentials -> Jenkins -> Global credentials -> Add Credentials

key	value
Kind	Username with password
Scope	Global
Username	ci
Password	****

Add our GitHub enterprise

Configure System -> GitHub Enterprise Servers

key	value
API endpoint	http://***/api/v3
Name	GitHub Enterprise

Create a job

New Item -> GitHub Organization -> OK

Configure the job's settings

<Job> -> Configure -> Projects

key	value
API endpoint	GitHub Enterprise (http://***/api/v3)
Credentials	ci/****
Owner	some-repogitory
Script Path	Jenkinsfile

<Job> -> Configure -> Projects -> Behaviours

key	value
Filter by name (with regular expression)	some-repogitory
Discover pull request from forks - Strategy	Merging the pull request with the current target branch revision
Discover pull request from forks - Trust	Everyone

Create a webhook in GitHub

To hook PR in Jenkins, We need to create a webhook in GitHub. Note that we must use the user has right permission.

<your repository> -> Settings -> Hooks

key	value
Payload URL	http://***/github-webhook/
Content type	application/json
Which events would you like to trigger this webhook?	Send me everything
Active	true

Disable Jenkins' authentication

Because we use Jenkins in a secure place, there are no incoming packets from the internet.

Manage Jenkins -> Configure Global Security -> Access Control -> Authorization -> check Anyone can do anything

Upgrade Jenkins

Since jenkins_home Docker volume has all Jenkins' setting files, We pull a latest Docker image and relaunch Docker container, that's it!

$ sudo docker stop jenkins
$ sudo docker rm jenkins
$ sudo docker pull jenkins/jenkins:lts
$ cd app/docker/dockerfiles/jenkins
$ docker build --rm --tag jenkins-docker:latest .
$ sudo docker run --env JAVA_OPTS=-Dorg.apache.commons.jelly.tags.fmt.timeZone=Asia/Tokyo -v /var/run/docker.sock:/var/run/docker.sock --name jenkins -d -p 80:8080 -p 50000:50000 -v jenkins_home:/var/jenkins_home jenkins-docker:latest

Jenkinsfile template

The Jenkinsfile we use, almost same, like this;

pipeline {
    agent any

    stages {
        stage('Checkout') {
            steps {
                step($class: 'GitHubSetCommitStatusBuilder')
                checkout scm
            }
        }

        stage('Start up containers') {
            steps {
                sh "sudo docker network create ci${env.EXECUTOR_NUMBER}"

                sh "sudo docker run -d --name mysql${env.EXECUTOR_NUMBER} --network ci${env.EXECUTOR_NUMBER} -p 3306${env.EXECUTOR_NUMBER}:3306 circleci/mysql:5.7"
                sleep(10)
                sh "sudo docker run -d --name redis${env.EXECUTOR_NUMBER} --network ci${env.EXECUTOR_NUMBER} redis:4.0"

                script {
                    if (sh (
                            script: "sudo docker create --name golang${env.EXECUTOR_NUMBER} --network ci${env.EXECUTOR_NUMBER} golang:latest bash /go/src/app/docker/test/test.sh",
                            returnStatus: true
                    ) == 0) {
                        sh "sudo docker cp ${env.WORKSPACE} golang${env.EXECUTOR_NUMBER}:/go/src/leo-server"
                    }
                }
            }
        }

        stage('Initialize containers') {
            steps {
                // Initialize something like DB
            }
        }

        stage('Unit test') {
            steps {

                script {
                    if (sh (
                            script: "sudo docker start -a golang${env.EXECUTOR_NUMBER}",
                            returnStatus: true
                    ) != 0) {
                        currentBuild.result = 'FAILURE'
                    }
                }

                // Copy test report and convert it into junit xml report
                sh "sudo docker cp golang${env.EXECUTOR_NUMBER}:/go/src/app/report.xml ."

                step([$class: 'JUnitResultArchiver', testResults: 'report.xml'])
            }
        }
    }

    post {
        always {
            sh script: "sudo docker stop mysql${env.EXECUTOR_NUMBER}", returnStatus: true
            sh script: "sudo docker stop redis${env.EXECUTOR_NUMBER}", returnStatus: true

            sh script: "sudo docker rm mysql${env.EXECUTOR_NUMBER}", returnStatus: true
            sh script: "sudo docker rm redis${env.EXECUTOR_NUMBER}", returnStatus: true
            sh script: "sudo docker rm golang${env.EXECUTOR_NUMBER}", returnStatus: true

            sh script: "sudo docker network rm ci${env.EXECUTOR_NUMBER}", returnStatus: true
        }
    }
}

Our test script, test.sh, like this;

#!/bin/bash

sudo chown -R circleci:circleci /go/src

cd /go/src/leo-server

echo 'Installing go-packages...'
glide i

echo 'Migrating DBs...'
go get bitbucket.org/liamstask/goose/cmd/goose
goose -env=ci -path=database/user up

echo 'Installing testing libraries...'
go get -u github.com/jstemmer/go-junit-report

echo 'Testing...'
go test -v ./... 2>&1 > tmp
status=$?
go-junit-report < tmp > report.xml

exit ${status}