jenkins pipeline docker build on docker agent

1
votes

I've got a jenkins declarative pipeline build that runs gradle and uses a gradle plugin to create a docker image. I'm also using a dockerfile agent directive, so the entire thing runs inside a docker container. This was working great with jenkins itself installed in docker (I know, that's a lot of docker). I had jenkins installed in a docker container on docker for mac, with -v /var/run/docker.sock:/var/run/docker.sock (DooD) per https://jpetazzo.github.io/2015/09/03/do-not-use-docker-in-docker-for-ci/. With this setup, the pipeline docker agent ran fine, and the docker build command within the pipeline docker agent ran fine as well. I assumed jenkins also mounted the docker socket on its inner docker container.

Now I'm trying to run this on jenkins installed on an ec2 instance with docker installed properly. The jenkins user has the docker group as its primary group. The jenkins user is able to run "docker run hello-world" successfully. My pipeline build starts the docker agent container (based on the gradle image with various things added) but when gradle attempts to run the docker build command, I get the following:

* What went wrong:
Execution failed for task ':docker'.
> Docker execution failed
  Command line [docker build -t config-server:latest /var/lib/****/workspace/nfig-server_feature_****-HRUNPR3ZFDVG23XNVY6SFE4P36MRY2PZAHVTIOZE2CO5EVMTGCGA/build/docker] returned:
  Cannot connect to the Docker daemon. Is the docker daemon running on this host?

Is it possible to build docker images inside a docker agent using declarative pipeline?

1
dockerjenkins

1 Answers

1
votes

Yes, it is.

The problem is not with Jenkins' declarative pipeline, but how you're setting up and running things.

From the error above, looks like there's a missing permission which needs to be granted.

Maybe if you share what your configuration looks like and how your're running things, more people can help.