How do I set up postgres database in Jenkins pipeline? - docker

Question

I am using docker to simulate postgres database for my app. I was testing it in Cypress for some time and it works fine. I want to set up Jenkins for further testing, but I seem stuck.
On my device, I would use commands
docker create -e POSTGRES_DB=myDB -p 127.0.0.1:5432:5432 --name myDB postgres
docker start myDB
to create it. How can I simulate this in Jenkins pipeline? I need the DB for the app to work.
I use Dockerfile as my agent, and I have tried putting the ENV variables there, but it does not work. Docker is not installed on the pipeline.
The way I see it is either:
Create an image by using a
Somehow install docker inside the pipeline and use the same commands
Maybe with master/slave nodes? I don't understand them well yet.

Answer 1

This might be a use case for sidecar pattern one of Jenkins Pipeline's advanced features.
For example (from the above site):
node {
checkout scm
docker.image('mysql:5').withRun('-e "MYSQL_ROOT_PASSWORD=my-secret-pw"') { c ->
docker.image('mysql:5').inside("--link ${c.id}:db") {
/* Wait until mysql service is up */
sh 'while ! mysqladmin ping -hdb --silent; do sleep 1; done'
}
docker.image('centos:7').inside("--link ${c.id}:db") {
/*
* Run some tests which require MySQL, and assume that it is
* available on the host name `db`
*/
sh 'make check'
}
}
}
The above example uses the object exposed by withRun, which has the
running container’s ID available via the id property. Using the
container’s ID, the Pipeline can create a link by passing custom
Docker arguments to the inside() method.
Best thing is that the containers should be automatically stopped and removed when the work is done.
EDIT:
To use docker network instead you can do the following (open Jira to support this OOTB). Following helper function
def withDockerNetwork(Closure inner) {
try {
networkId = UUID.randomUUID().toString()
sh "docker network create ${networkId}"
inner.call(networkId)
} finally {
sh "docker network rm ${networkId}"
}
}
Actual usage
withDockerNetwork{ n ->
docker.image('sidecar').withRun("--network ${n} --name sidecar") { c->
docker.image('main').inside("--network ${n}") {
// do something with host "sidecar"
}
}
}

Answer 2

For declarative pipelines:
pipeline {
agent any
environment {
POSTGRES_HOST = 'localhost'
POSTGRES_USER = myuser'
}
stages {
stage('run!') {
steps {
script {
docker.image('postgres:9.6').withRun(
"-h ${env.POSTGRES_HOST} -e POSTGRES_USER=${env.POSTGRES_USER}"
) { db ->
// You can your image here but you need psql to be installed inside
docker.image('postgres:9.6').inside("--link ${db.id}:db") {
sh '''
psql --version
until psql -h ${POSTGRES_HOST} -U ${POSTGRES_USER} -c "select 1" > /dev/null 2>&1 || [ $RETRIES -eq 0 ]; do
echo "Waiting for postgres server, $((RETRIES-=1)) remaining attempts..."
sleep 1
done
'''
sh 'echo "your commands here"'
}
}
}
}
}
}
}
Related to Docker wait for postgresql to be running