Jenkins docker.image().withRun() what host name do I use to connect - node.js

Question

I have a Jenkins pipeline and I'm trying to run a Postgres container and connect to it for some nodejs integrations tests. My Jenkins file looks like this:
stage('Test') {
steps {
script {
docker.image('postgres:10.5-alpine').withRun('-e "POSTGRES_USER=fred" -e "POSTGRES_PASSWORD="foobar" -e "POSTGRES_DB=mydb" -p 5432:5432') { c->
sh 'npm run test'
}
}
}
What hostname should I use to connect to the postgres database inside of my nodejs code? I have tried localhost but I get a connection refused exception:
ERROR=Error: connect ECONNREFUSED 127.0.0.1:5432
ERROR:Error: Error: connect ECONNREFUSED 127.0.0.1:5432
Additional Details:
I've added a sleep for 30 seconds for the container to start up. I know there are better ways to do this but for now I just want to solve the connection problem.
I run docker logs on the container to see if it is ready to accept connections, and it is.
stage('Test') {
steps {
script {
docker.image('postgres:10.5-alpine').withRun('-e "POSTGRES_USER=fred" -e "POSTGRES_PASSWORD="foobar" -e "POSTGRES_DB=mydb" -p 5432:5432') { c->
sleep 60
sh "docker logs ${c.id}"
sh 'npm run test'
}
}
}
tail of docker logs command:
2019-09-02 12:30:37.729 UTC [1] LOG: database system is ready to accept connections
I am running Jenkins itself in a docker container, so I am wondering if this is a factor?
My goal is to have a database startup with empty tables, run my integration tests against it, then shut down the database.
I can't run my tests inside of the container because the code I'm testing lives outside the container and triggered the jenkins pipeline to begin with. This is part of a Jenkins multi-branch pipeline and it's triggered by a push to a feature branch.

Answer 1

your code sample is missing a closing curly bracket and has an excess / mismatched quote. That way it is not clear whether you actually did (or wanted to) run your sh commands, inside or outside the call.
Depending on where the closing bracket was, the container might already have shut down.
Generally, the Postgres connection is fine with that fixed syntax issues:
pipeline {
agent any
stages {
stage('Test') {
steps {
script {
docker.image('postgres:10.5-alpine')
.withRun('-e "POSTGRES_USER=fred" '+
'-e "POSTGRES_PASSWORD=foobar" '+
'-e "POSTGRES_DB=mydb" '+
'-p 5432:5432'
){
sh script: """
sleep 5
pg_isready -h localhost
"""
//sh 'npm run test'
}
}
}
}
}
}
results in:
pg_isready -h localhost
localhost:5432 - accepting connections