How to set .gitlab-ci.yml to only run the tasks on one node and only update or push the repo to other nodes (docker-swarm)?

Question

This is my .gitlab-ci.yml file in my repo:

image: docker 

#services:
#  - docker:dind

stages:
  - build
  - deploy

build-prod:
  stage: build
  only:
    - master
  tags:
    - docker
  script:
    - docker network create -d overlay reprox
  environment: master


deploy-prod:
  stage: deploy
  only:
    - master
  tags:
    - docker  
  script:
    - docker stack deploy -c ./site1/docker-compose.yml site1
    - docker stack deploy -c ./site2/docker-compose.yml site2 
    - docker stack deploy -c ./site3/docker-compose.yml site3
    - docker stack deploy -c ./reverse-proxy/docker-compose.yml proxy  
  environment: master

So my setup is 1 manager and 2 worker nodes and I only need to run build and deploy jobs on manager node, other nodes just need to have the repo, no need for running the bash commands on worker nodes.

I added a manager runner with "docker" tag and worker nodes with "runner" tag.

Answer 1

Remove your docker tag. You can configure your workers to work only on specific tags

job1:
  tags:
    - dockernode_1
job2:
  tags:
    - dockernode_2

Your previously used docker tag was probably just a workaround (or from a tutorial) to make the runners work on all jobs. If you don't want a runner to care about tagging, you can make him pick up all available jobs.