variant: flatcar
version: 1.0.0

# Dozzle log viewer hub.
#
# Aggregates container logs from the dozzle agents running on the other Flatcar
# VMs (see the dozzle-agent units in the other butane configs) and, via the
# local socket, from this host's own containers. Reachable on :8080.
#
# No state is kept on disk: /data is a tmpfs, so the container is fully
# disposable and there is nothing to back up. That is also why simple auth
# (users.yml) is not used -- it would need a persistent /data.
#
# Hub <-> agent traffic is TLS, using the certificate pair baked into the
# dozzle image. Every hub and agent on the same image version shares it, so
# nothing needs mounting here -- which is also why the agents must stay pinned
# to the same tag as the hub. To move to a custom pair later, generate one
# with (writes into $PWD):
#
#   docker run --rm -v "$PWD":/out amir20/dozzle:v11.1.1 generate-certs \
#     --cert-out /out/dozzle_cert.pem --key-out /out/dozzle_key.pem
#
# ...then mount it at /dozzle_cert.pem and /dozzle_key.pem (read-only) on the
# hub and on every agent. Keep the key out of this file: it would end up in
# plaintext in the rendered Ignition snippet on the node's storage.

systemd:
  units:
    - name: dozzle.service
      enabled: true
      contents: |
        [Unit]
        Description=Dozzle log viewer hub
        After=docker.service
        Requires=docker.service
        [Service]
        TimeoutStartSec=0
        # Kept as unit environment rather than inline -e values so that
        # wait-for-agents.sh can read the agent list from the same place the
        # container does. docker run forwards them by bare name below.
        Environment="DOZZLE_HOSTNAME=Oswald Logs"
        Environment="DOZZLE_ENABLE_MCP=true"
        Environment="DOZZLE_REMOTE_AGENT=192.168.7.60:7007|oswald-runner|Goose,192.168.7.61:7007|ai|Goose,192.168.7.62:7007|oswl-connector|Goose,192.168.7.64:7007|cisa-kev-rss|Goose"
        # Pulled up front so a slow first pull is not mistaken for a hung unit.
        ExecStartPre=/usr/bin/docker pull amir20/dozzle:v11.1.1
        # Leading "-" so a missing container is not a failure.
        ExecStartPre=-/usr/bin/docker rm --force dozzle
        # If the hub starts before the agents are listening, the failed initial
        # handshake leaves a permanently-offline placeholder host in the UI
        # alongside the real one once it connects. Bounded and "-" prefixed, so
        # an agent that is genuinely gone delays the hub but never blocks it.
        ExecStartPre=-/usr/bin/timeout 180 /opt/dozzle/wait-for-agents.sh
        # Foreground (no -d) so systemd supervises the container process.
        ExecStart=/usr/bin/docker run --rm --name dozzle \
          -v /var/run/docker.sock:/var/run/docker.sock:ro \
          --tmpfs /data \
          -p 8080:8080 \
          -e DOZZLE_HOSTNAME \
          -e DOZZLE_ENABLE_MCP \
          -e DOZZLE_REMOTE_AGENT \
          amir20/dozzle:v11.1.1
        ExecStop=/usr/bin/docker stop dozzle
        Restart=always
        RestartSec=5s
        [Install]
        WantedBy=multi-user.target

storage:
  files:
    # Blocks until every agent named in DOZZLE_REMOTE_AGENT accepts a TCP
    # connection. The list is read from the environment, so adding or removing
    # an agent above needs no change here.
    - path: /opt/dozzle/wait-for-agents.sh
      mode: 0755
      contents:
        inline: |
          #!/usr/bin/bash
          # Note: /dev/tcp is unavailable -- Flatcar's bash is built without
          # net redirections -- so reachability is probed with curl. The agent
          # speaks gRPC over TLS, so any completed connection answers with a
          # protocol error; only exit 7 (refused) and 28 (timeout) mean the
          # agent is not up yet.
          if [ -z "$DOZZLE_REMOTE_AGENT" ]; then
            exit 0
          fi

          for entry in $(echo "$DOZZLE_REMOTE_AGENT" | tr ',' ' '); do
            # Strip the |name|group suffix; what is left is host:port.
            hostport=$(echo "$entry" | cut -d'|' -f1)
            while true; do
              curl -sk -o /dev/null --max-time 3 "https://$hostport"
              rc=$?
              case "$rc" in
                7|28)
                  echo "waiting for dozzle agent $hostport"
                  sleep 2
                  ;;
                *)
                  break
                  ;;
              esac
            done
          done