migrate portainer agent to be managed by portainer

portainer-agent-template.md

Description

This template deploys the portainer agent via portainer. I wanted a way to update the agent independently from the portainer web app. This is not a supported deployment architecture by portainer (which makes it odd they have the agent template in templates, any hoo)

DO NOT DO ANY OF THIS UNLESS YOU ARE PREPARED TO RESINTALL PORTAINER AND ITS AGENTS IF YOU GET ANY STEP WRONG YOU WILL BREAK PORTAINER

State Considerations for SWARM

none, this container can be cofigured entirely by the stack file

Network Considerations

the agent and portainer need to be on the same network to make that full deterministic i chose to create the network manually in the portainer in the UI this makes the network 'external' to the stack

DO NOT DELETE OR STOP OLD AGENTS UNTIL YOU KNOW NEW AGENTS WORK

i reccommend that you:

1. make the new portainer network overlay
2. you make it attachable
3. you use the portainer UI to attach your running portainer web app service / container instance to this new network in addition to its default
4. you deploy this stack
5. you retarget the environment at these new agent and ensure you can access them
6. you then remove the old agent service from the UI (but not the portainer stack or web app)
7. you edit the original compose file to remove the agent lines AND change it to so the portainer instance now uses the new portainer external network
8. then you take the plunge and redeploy the portainer compose from the command line

Once this all up and running you should still have a working system, you may find stacks marked as orhpnaned, this is not an issue, just click on the stack and then click associate

Placement Considerations

None, by default this template will result in the agent being deployed to all nodes

  agent:
    image: portainer/agent
    environment:
      AGENT_CLUSTER_ADDR: tasks.agent   # note this is important to remeber this is what you use for the agent address
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
      - /var/lib/docker/volumes:/var/lib/docker/volumes
    ports:                             # by publishing these you can also connect to the agent using node ip address : port if needed
      - target: 9001
        published: 9001
        protocol: tcp
        mode: host
    networks:
      - portainer
    deploy:
      mode: global
      placement:
        constraints: [node.platform.os == linux]

networks:
  portainer:
    external: true

It's odd that the only Limited stack I have on Portainer is the one of Portainer itself!

Would be nice to have this whole stack under control of Portainer.

Would be nice to have this whole stack under control of Portainer.

do you really want that... i have been running like for a year now.... its both elegant and dangerous - the key is to have backups for your stacks - that way if you eff up portainer the way to recover it is delete the stack and services and the rerun the stack file by hand... i have only had to do that once..... but i will post my stack if you want it....

ok added to the main list... just some ramblings and my stack - can't recall the exact steps i took, i know it was scary and i think i had to do some stops and starts at the command line - I will see if i can find some notes....
https://gist.github.com/scyto/46fa1f8d1b73663dc6cce5d8b2a4826a

proof :-)

@scyto Cool, It was also my thinking, to just deploy another Portainer Stack using different ports.
I put to this on my nice to have list!

I put to this on my nice to have list!

just make sure you backup everything :-)