Calling docker stack deploy on a docker host from within a Jenkins container

[Ethan Wilansky]

I've posted this to stackoverflow, but after a number of views, I haven't
gotten an answer or even a suggestion. I'm hoping by posting the same
question here, this community might have a suggestion. For reference, the
stackoverflow post
is: https://stackoverflow.com/questions/52920540/calling-docker-stack-deploy-on-a-docker-host-from-within-a-jenkins-container.
Here's the post:

On my OS X host, I'm using Docker CE (18.06.1-ce-mac73 (26764)) with
Kubernetes enabled and using Kubernetes orchestration. From this host, I
can run a stack deploy to deploy a container to Kubernetes using this
simple docker-compose file (kube-compose.yml):

version: '3.3'
services:
web:
image: dockerdemos/lab-web
volumes:
- "./web/static:/static"
ports:
- "9999:80"
and this command-line run from the directory containing the compose file:

docker stack deploy --compose-file ./kube-compose.yml simple_test
However, when I attempt to run the same command from my Jenkins container,
Jenkins returns:

*this node is not a swarm manager. Use "docker swarm init" or "docker swarm
join" to connect this node to swarm and try again*

I do not want the docker client in the Jenkins container to be initialized
for a swarm since I'm not using Docker swarm on the host.

The Jenkins container is defined in a docker-compose to include a volume
mount to the docker host socket endpoint:

version: '3.3'
services:
jenkins:
# contains embedded docker client & blueocean plugin
image: jenkinsci/blueocean:latest
user: root
ports:
- "8080:8080"
- "50000:50000"
volumes:
- ./jenkins_home:/var/jenkins_home
# run Docker from the host system when the container calls it.
- /var/run/docker.sock:/var/run/docker.sock
# root of simple project
- .:/home/project
container_name: jenkins

I have also followed this guide to proxy requests to the docker host with
socat: https://github.com/docker/for-mac/issues/770 and here:
Docker-compose: deploying service in multiple hosts.

Finally, I'm using the following Jenkins definition (Jenkinsfile) to call
stack to deploy on my host. Jenkins has the Jenkins docker plug-in
installed:

node {
checkout scm

stage ('Deploy To Kube') {
docker.withServer('tcp://docker.for.mac.localhost:1234') {
sh 'docker stack deploy app --compose-file
/home/project/kube-compose.yml'
}
}
}
I've also tried changing the withServer signature to:

docker.withServer('unix:///var/run/docker.sock')
and I get the same error response. I am, however, able to telnet to the
docker host from the Jenkins container so I know it's reachable. Also, as I
mentioned earlier, I know the message is saying to run swarm init, but I am
not deploying to swarm.

I checked the version of the docker client in the Jenkins container and it
is the same version (Linux variant, however) as I'm using on my host:

Docker version 18.06.1-ce, build d72f525745

Here's the code I've described:
https://github.com/ewilansky/localstackdeploy.git

Please let me know if it's possible to do what I'm hoping to do from the
Jenkins container. The purpose for all of this is to provide a simple,
portable demonstration of a pipeline and deploying to Kubernetes is the
last step. I understand that this is not the approach that would be taken
anywhere outside of a local development environment.