Changing the host for a Portainer Edge Agent

Introduction

In my last article, Deploying Proxmox 7 behind a firewall VM, I discussed moving away from several VPS providers to a bare-metal server running as a hypervisor with Proxmox. After I moved all of my virtual servers over to Proxmox, I needed to change the host on each of the virtual servers’ Portainer Edge Agents, and there wasn’t an easy way to do that since it’s encoded.

First, let’s look at the Docker-Compose file that I have provisioned on one of the virtual servers. I have a file like this on each server for running the Portainer Edge Agent, and the difference between each of the files are the environment variables EDGE_ID and EDGE_KEY:

---
# Load balancer 3

version: "3.5"

services:

    portainer_edge_agent:

        container_name: portainer_edge_agent
        image: portainer/agent:latest
        restart: always

        environment:
            - EDGE=1
            - EDGE_ID=111-222-333-444-555
            - EDGE_KEY=aHR0cHM6Ly8xLjIuMy40Ojk0NDN8MS4yLjMuNDo4MDAwfEZpbmdlcnByaW50fEFnZW50SUQ
            - EDGE_INSECURE_POLL=1

        volumes:
            - /var/run/docker.sock:/var/run/docker.sock
            - /var/lib/docker/volumes:/var/lib/docker/volumes
            - /:/host
            - /srv/portainer:/data

        labels:
            - "diun.enable=true"

To decode the data, run this shell script at the command line:

{
    read -p "Portainer Edge Key: " PORTAINER_KEY
    echo ${PORTAINER_KEY:0:${#PORTAINER_KEY}&-4} | basenc --base64url --decode; echo;
}

If you entered the Edge Key that I used in the above example, the data will be decoded to:

https://1.2.3.4:9443|1.2.3.4:8000|Fingerprint|AgentID

Update the Portainer Host’s IP/DNS to your new server and run this command to encode it:

{
    read -p "Portainer Edge Data: " PORTAINER_KEY
    echo -n "${PORTAINER_KEY}" | basenc --base64url --wrap=0; echo;
}

Suppose that I changed from 1.2.3.4 to example.com, then my unencoded data would be:

https://example.com:9443|example.com:8000|Fingerprint|AgentID

The result would be:

aHR0cHM6Ly9leGFtcGxlLmNvbTo5NDQzfGV4YW1wbGUuY29tOjgwMDB8RmluZ2VycHJpbnR8QWdlbnRJRA==

Get rid of any equals signs at the end and paste that as your new EDGE_KEY into the Docker Compose file from above:

/etc/docker/compose/portainer/docker-compose.yaml

---
# Load balancer 3

version: "3.5"

services:

    portainer_edge_agent:

        container_name: portainer_edge_agent
        image: portainer/agent:latest
        restart: always

        environment:
            - EDGE=1
            - EDGE_ID=111-222-333-444-555
            - EDGE_KEY=aHR0cHM6Ly9leGFtcGxlLmNvbTo5NDQzfGV4YW1wbGUuY29tOjgwMDB8RmluZ2VycHJpbnR8QWdlbnRJRA
            - EDGE_INSECURE_POLL=1

        volumes:
            - /var/run/docker.sock:/var/run/docker.sock
            - /var/lib/docker/volumes:/var/lib/docker/volumes
            - /:/host
            - /srv/portainer:/data

        labels:
            - "diun.enable=true"

Now restart the Portainer Edge Agent:

docker compose down && docker compose up -d

External links

• Portainer GitHub Issue: Add the ability to define the tunnel URL for Edge Agent deployments #6251
  • https://github.com/portainer/portainer/issues/6251#issue-1076403096
    • Portainer GitHub Issue: Use Traefik for Edge Agent service #24
      • https://github.com/portainer/portainer-compose/issues/24#issuecomment-942389178

References

LTG.FYI/Portainer-Decode

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