Start Rancher on RancherOS using Cloud-Init without public IP

Rancher 1.x
1

Hi,

as I hard some problems finding out how to run RancherOS images in OpenStack that auto-start Rancher agents without a public IP - as I want to build a VPC-ish setup for security reasons - here is how I got it to work:

#cloud-config
write_files:
  - path: /etc/rc.local
    permissions: "0755"
    owner: root
    content: |
      #!/bin/bash
      # Workaround until fixed: https://github.com/rancher/os/issues/900
      /sbin/ip link set mtu 1450 dev eth0
      # Wait until Docker is running
      wait-for-docker
      docker run --rm --privileged -e CATTLE_AGENT_IP=$(ip route get 1 | awk '{print $NF;exit}') -v /var/run/docker.sock:/var/run/docker.sock -v /var/lib/rancher:/var/lib/rancher $rancher_agent_image $rancher_registration_url

Because I have to use a dynamic CATTLE_AGENT_IP I could not use the somewhat nicer service approach:

#cloud-config
services:
  rancher-agent1:
    image: $rancher_agent_image
    command: $rancher_registration_url
    privileged: true
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    environment:
      CATTLE_AGENT_IP: ???

as I’m pretty sure it’s not possible to execute shell commands in this definition.