Multi Node Ssh

Multi-Node SSH Patterns

LAN hosts sit behind the OpenWrt router on 10.10.10.0/24 and are NOT directly reachable from the controller. All SSH goes through the primary Proxmox host via ProxyCommand. LAN hosts are ONLY reachable when the OpenWrt router VM is running on the primary host.

Rules

• NEVER assume LAN hosts are reachable without the OpenWrt baseline running. Plays targeting lan_hosts MUST come after the OpenWrt configure play in site.yml. Molecule scenarios for LAN hosts MUST verify the baseline first.
• NEVER remove SSH authorized_keys or API tokens in cleanup. These are operator prerequisites, not playbook artifacts.
• NEVER manage SSH keys or passwords in playbooks. The operator sets up key auth manually via the Proxmox GUI shell or ssh-copy-id through the tunnel.
• ALWAYS add ServerAliveInterval=15 and ServerAliveCountMax=4 to SSH args for ProxyCommand connections. Without keepalives, the connection drops during long sequences of local Ansible tasks that don't send traffic.
• ALWAYS export env vars before running Molecule: set -a; source test.env; set +a; molecule test -s mesh1-infra

Architecture

Controller (laptop, 192.168.86.0/24)
  └──SSH──► Primary host (home, 192.168.86.201)
               ├──SSH──► OpenWrt VM (10.10.10.1, manages LAN)
               └──ProxyCommand──► LAN host (mesh1, 10.10.10.210)

Dependency chain: controller → home → OpenWrt VM → LAN exists → mesh1 reachable.

Patterns

Adding a new LAN node (full checklist)

1. Physical setup: connect the node to the LAN switch behind OpenWrt
2. Discover the node from the primary host:

# Check OpenWrt DHCP leases
ssh root@10.10.10.1 'cat /tmp/dhcp.leases'
# Or scan the subnet
for i in $(seq 200 220); do ping -c1 -W1 10.10.10.$i &>/dev/null && echo 10.10.10.$i; done

3. Set up SSH key auth (one-time, requires console or Proxmox GUI):

# Option A: SSH tunnel + GUI shell
ssh -L 8007:<node-ip>:8006 root@192.168.86.201
# Browse https://localhost:8007, open Shell, paste public keys

# Option B: ssh-copy-id through ProxyCommand (requires password)
ssh-copy-id -o "ProxyCommand=ssh -o ServerAliveInterval=15 -o ServerAliveCountMax=4 -W %h:%p root@192.168.86.201" root@<node-ip>

Both the controller's AND the primary host's keys must be authorized.

4. Add env var: NODENAME_API_TOKEN= to .env/test.env
5. Add to inventory: inventory/hosts.yml under lan_hosts
6. Create host_vars: inventory/host_vars/nodename.yml with ansible_host
7. Run bootstrap: the tasks/bootstrap_lan_host.yml task handles DHCP lease and API token creation automatically during converge
8. Verify: ssh -o "ProxyCommand=ssh -o ServerAliveInterval=15 -o ServerAliveCountMax=4 -W %h:%p root@$PRIMARY_HOST" root@<node-ip> hostname

SSH tunnel for browser access

ssh -L 8007:<lan-host-ip>:8006 root@192.168.86.201
# Then browse: https://localhost:8007

BAD: Cleanup removes credentials

# BAD -- this locks out the remote node permanently
- name: Remove SSH keys
  file: path=/root/.ssh/authorized_keys state=absent

- name: Remove API token
  command: pveum user token remove root@pam ansible

GOOD: Cleanup only removes playbook artifacts

# GOOD -- only touch what the playbook created
- name: Remove ansible-managed files
  file: path={{ item }} state=absent
  loop:
    - /etc/network/interfaces.d/ansible-bridges.conf
    - /etc/ansible/facts.d/vm_builds.fact

Environment variable convention

PRIMARY_HOST=192.168.86.201          # Primary Proxmox host IP
HOME_API_TOKEN=cab59c9a-...          # matches inventory_hostname "home"
MESH1_API_TOKEN=39d2976f-...         # matches inventory_hostname "mesh1"

Convention: <INVENTORY_HOSTNAME>_API_TOKEN (uppercased, hyphens → underscores).

group_vars/proxmox.yml resolves dynamically — no per-host override needed:

proxmox_api_token_secret: >-
  {{ lookup('env', (inventory_hostname | upper | replace('-', '_')) + '_API_TOKEN') }}

Inventory layout

# inventory/hosts.yml
proxmox:
  children:
    lan_hosts:
      hosts:
        mesh1: {}

# inventory/group_vars/lan_hosts.yml
# ProxyCommand (not ProxyJump) — so we can pass keepalives to the jump connection.
ansible_ssh_common_args: >-
  -o ProxyCommand="ssh
  -o ServerAliveInterval=15
  -o ServerAliveCountMax=4
  -o StrictHostKeyChecking=no
  -o UserKnownHostsFile=/dev/null
  -W %h:%p root@{{ lookup('env', 'PRIMARY_HOST') }}"
  -o StrictHostKeyChecking=no
  -o UserKnownHostsFile=/dev/null
  -o ConnectTimeout=30
  -o ServerAliveInterval=15
  -o ServerAliveCountMax=4

Connection hardening

Three layers prevent mid-play SSH drops through the ProxyCommand tunnel:

1. ansible.cfg: ControlPersist=300s + ServerAliveInterval=15 on ALL connections.
2. lan_hosts.yml: ProxyCommand (not ProxyJump) with keepalives on the jump connection.
3. site.yml: meta: reset_connection + wait_for_connection pre_tasks on the first Phase 2 play targeting lan_hosts.

Previous bug: mesh1 became UNREACHABLE mid-play during proxmox_igpu (54 tasks ok, then "Data could not be sent"). Root cause: the ControlMaster carrying the ProxyCommand tunnel had no keepalives and could silently die.

Bootstrap flow (tasks/bootstrap_lan_host.yml)

Called from the primary host (router_nodes):

1. Verifies SSH key auth — fails with setup instructions if not working
2. Creates DHCP static lease on OpenWrt (if missing)
3. Creates API token on the LAN host (if missing)
4. Saves token to test.env on the controller

Default test includes LAN nodes

The default molecule test scenario exercises BOTH home (primary) and mesh1 (LAN satellite). site.yml is phased so LAN hosts are only contacted after OpenWrt creates the LAN:

1. Phase 1: backup + infra + OpenWrt on proxmox:!lan_hosts (home only)
2. Phase 2: bootstrap + backup + infra on lan_hosts (mesh1)
3. Phase 3: services on flavor groups spanning both (e.g., vpn_nodes)

The separate mesh1-infra scenario is still available for quick iteration on mesh1 hardware issues without running the full ~10 minute default suite.

Baseline workflow for LAN nodes

LAN nodes (mesh1) are ONLY reachable when the OpenWrt baseline is running. Prefer keeping the baseline up between test runs:

molecule converge                  # build/update baseline (idempotent, both nodes)
molecule verify                    # verify both nodes
molecule converge -s mesh1-infra   # infra-only on mesh1 (quick iteration)
molecule verify -s mesh1-infra     # verify mesh1 infra only

# Clean-state validation only when needed:
molecule test                      # full pipeline — destroys everything
molecule converge                  # restore baseline for further work

Molecule scenario for LAN nodes

# molecule/mesh1-infra/molecule.yml (key sections)
platforms:
  - name: home
    groups: [proxmox, router_nodes]
  - name: mesh1
    groups: [proxmox, lan_hosts]

provisioner:
  env:
    HOME_API_TOKEN: ${HOME_API_TOKEN}
    PRIMARY_HOST: ${PRIMARY_HOST}
    MESH1_API_TOKEN: ${MESH1_API_TOKEN}

Test sequence: dependency → syntax → converge → verify → cleanup (no initial cleanup — baseline must exist).

Troubleshooting

LAN host unreachable

1. Verify OpenWrt is running: qm status 100 on the primary host
2. Verify LAN bridge IP: ip -4 addr show | grep 10.10.10 on the primary host
3. Ping from primary: ping -c1 10.10.10.210
4. Check DHCP lease: ssh root@10.10.10.1 'cat /tmp/dhcp.leases'

SSH "Permission denied"

1. Verify key auth from primary: ssh -o BatchMode=yes root@10.10.10.210 hostname
2. Re-push keys via Proxmox GUI shell or SSH tunnel (see "Adding a new LAN node")

DHCP lease drift

If the node gets a different IP after router reboot, the DHCP static lease may not have been committed. Check on OpenWrt: uci show dhcp | grep mesh1 — if empty, re-run the bootstrap.

API token issues

1. List tokens: pveum user token list root@pam on the LAN host
2. Create: pveum user token add root@pam ansible --privsep=0
3. Save to test.env: MESH1_API_TOKEN=<value>