jenkins pipeline DOCKER_HOST - docker

Question

I need to run a docker-container inside my pipeline.
My problem is, there is no docker.sock available inside the Jenkins-container. And actual no chance to get it.
But I found some jobs using docker with this Option:
"Inject environment variables to the build process" -> "Properties
Content"
And following configured:
DOCKER_HOST=tcp://<ip>:<port>
DOCKER_CERT_PATH=/var/jenkins_home/certs
In my understanding, this is equivalent to the docker.sock and useable as plugin, isnt it?
But how can i use it inside a (multi-)pipeline project?
I've tried using this Block inside my Note:
environment {
DOCKER_HOST = 'tcp://<ip>:<port>'
DOCKER_CERT_PATH = '/var/jenkins_home/certs'
}
But got same issue: "docker: not found"
I might have a logical fallacy. Hope someone could help.
Otherwise is it possible to create a jenkins-slave including a docker.sock?

Answer 1

But got same issue: "docker: not found"
This indicates that your Jenkins slave, the one running the pipeline script, does not have the docker command line tools. This depends on your distribution, but in my case I fixed it by changing my build-slave/pipeline-runner creation steps to include:
yum install -y docker-client
Note that you'll still need that for the Cloudbees docker plugin (the thing which provides stuff like docker.build() and docker.image()) because it translates those nice pipeline directives down into shell commands.