Cannot get Jenkins Docker slave to build docker images - jenkins

Question

I am currently experimenting with Docker in combination with Jenkins to streamline the CI/CD workflow for a new project. I do so on a Mac with Docker 1.12 installed.
This is what I do:
Use docker machine to create a new Docker server
Use the official Jenkins Docker image to spin up a Jenkins instance on that server
Install the "Yet Another Docker Plugin" and "CloudBees Docker Pipeline" plugins.
Add a "Docker Cloud" using the IP of the Docker server above and the third party Docker DinD image tehranian/dind-jenkins-slave
With this setup, I run a very simple pipeline job like this:
node('docker') {
docker.image('hseeberger/scala-sbt').inside {
stage 'Checkout'
echo 'We got here!'
}
}
Jenkins spins up a Docker instance as expected and executes the job. So the basic Docker setup is working as expected.
But the Docker command within the job fails. Log output looks something like this:
[Pipeline] node
Still waiting to schedule task
Docker-23ebf3d8dd4f is offline
Running on Docker-23ebf3d8dd4f in /home/jenkins/workspace/docker-test
[Pipeline] {
[Pipeline] sh
[docker-test] Running shell script
+ docker inspect -f . hseeberger/scala-sbt
Cannot connect to the Docker daemon. Is the docker daemon running on this host?
[Pipeline] sh
[docker-test] Running shell script
+ docker pull hseeberger/scala-sbt
Using default tag: latest
Warning: failed to get default registry endpoint from daemon (Cannot connect to the Docker daemon. Is the docker daemon running on this host?). Using system default: https://index.docker.io/v1/
Cannot connect to the Docker daemon. Is the docker daemon running on this host?
[Pipeline] }
[Pipeline] // node
[Pipeline] End of Pipeline
Now when I browse around for solutions, it is usually mentioned that the Docker socket needs to be provided to the container as a volume, but that doesn't seem to work either.
Since the general setup seems to be working, wouldn't the slave simply have to do the same thing as the Jenkins plugin does to spin up the Docker slave in the first place? That is, use the URL of the Docker server to control it? Since I assume this is an extremely common use-case, there must be a Docker image for Jenkins Docker slaves that can do this out of the box, right? What am I missing?

Answer 1

You might need to set the docker env and use the content of docker-machine env node in your running shellscript.