🏔️ Alpine - Traefik Labels

SYNOPSIS

What can I do with this? This image will connect to all your Docker nodes and read their labels. It will then use the labels to update your Traefik configuration in Redis automatically and dynamically on each container start, stop or timeout. It also supports updating your internal and external DNS servers too, so you can use labels for everything. If a container is removed the image will automatically reverse any nsupdate update add to nsupdate update delete so entries are removed too.

In order to use this image, you need to setup Traefik with a Redis provider and then point this image via redis.url to the same Redis instance. Each entry will have an expire timer set in Redis, so that if a container is removed by a server crashing, Redis will automatically remove stale entries as well. Entries are refreshed every 300 seconds or on all docker container events (create, run, kill, stop, restart, ...). As for nsupdate, you need to setup tsig authentication in your NS servers and add the keys to the zones you want to be able to update, you can restrict the keys by using update-policy if you use BIND.

This image provides the ability to call a webhook for each container for each event or poll after the data was updates in Redis and or nsupdate.

Each node gets its own worker thread for better scalability. If you have 10 nodes, you will have 10 worker processes inside the container forked from the main process. Forks die when their node disconnects and use the ping.interval to fork new processes indefinitely. As soon as the node is back online, it will always execute a poll on all containers of that node.

VOLUMES

• /labels/etc - Directory of config.yaml
• /labels/ssl - Directory of ssl certificates for TLS¹

RUN

docker run --name traefik-labels \
  -v .../etc:/labels/etc \
  -v .../ssl:/labels/ssl \
  -d 11notes/traefik-labels:[tag]

EXAMPLES

config /labels/etc/config.yaml

labels:
  redis:
    url: rediss://foo:bar@10.127.198.254:6379/0
  webhook:
    url: https://my.cool.webhook/v1
    # optional
    auth:
      # supports basic authentication
      basic: labels:*****
  nodes:
    # use FQDN and add the FQDN to your certificates SAN list (or IP)
    - 192.168.18.12
    - 10.14.120.1
  # reload labels.nodes every {n} seconds (0 = disabled)
  interval: 0
  # timeout in seconds for the connection to a Docker node
  timeout: 2.5
  rfc2136:
    # only nsupdate on entries which are different (do not update same data)
    verify: false
  poll:
    # polling all containers on a node every {n} seconds
    interval: 300
  ping:
    # ping all nodes every {n} seconds to see if they are still online
    interval: 10
  tls:
    # path for TLS certificates
    ca: /labels/ssl/ca.crt
    crt: /labels/ssl/server.crt
    key: /labels/ssl/server.key

container on a node with Traefik routes

docker run --name traefik-demo \
  -p 8080:8080 \
  -l "traefik/http/routers/demo.domain.com/service=demo.domain.com" \
  -l "traefik/http/routers/demo.domain.com/rule=Host(`demo.domain.com`)" \
  -l "traefik/http/routers/demo.domain.com/tls=true" \
  -l "traefik/http/routers/demo.domain.com/entrypoints=https" \
  -l "traefik/http/services/demo.domain.com/loadbalancer/servers/0/url=http://fqdn-of-docker-node:8080" \
  -d 11notes/nginx:stable

container on a node with Traefik routes and rfc2136 DNS

docker run --name traefik-rfc2136-demo \
  -p 8080:8080 \
  -l "traefik/http/routers/demo.domain.com/service=demo.domain.com" \
  -l "traefik/http/routers/demo.domain.com/rule=Host(`demo.domain.com`)" \
  -l "traefik/http/routers/demo.domain.com/tls=true" \
  -l "traefik/http/routers/demo.domain.com/entrypoints=https" \
  -l "traefik/http/services/demo.domain.com/loadbalancer/servers/0/url=http://fqdn-of-docker-node:8080" \
  -l "rfc2136/WAN/server=ns.domain.com" \
  -l "rfc2136/WAN/key=algo:name:secret" \
  -l "rfc2136/WAN/nsupdate=update add foo.domain.com 300 A 175.12.41.11" \
  -l "rfc2136/WAN/nsupdate=update add foo.domain.com 300 TXT \"hello from traefik-labels!\"" \
  -l "rfc2136/LAN/server=ns.domain.local" \
  -l "rfc2136/LAN/key=algo:name:secret" \
  -l "rfc2136/LAN/nsupdate=update add foo.domain.local 300 A 192.168.12.54" \
  -d 11notes/nginx:stable

DEFAULT SETTINGS

Parameter	Value	Description
user	docker	user docker
uid	1000	user id 1000
gid	1000	group id 1000
home	/labels	home directory of user docker
config	/labels/etc/config.yaml	config (nodes can be updated dynamically)
ca.crt	/labels/ssl/ca.crt	Certificate of CA for TLS1
labels.crt	/labels/ssl/labels.crt	Certificate of client for TLS1
labels.key	/labels/ssl/labels.key	Private key of client for TLS1

ENVIRONMENT

Parameter	Value	Default
TZ	Time Zone
DEBUG	Show debug information

PARENT IMAGE

• 11notes/node:stable

BUILT WITH

• npm::redis
• npm::dockerode
• nodejs
• alpine

TIPS

• Only use rootless container runtime (podman, rootless docker)
• Allow non-root ports < 1024 via echo "net.ipv4.ip_unprivileged_port_start=53" > /etc/sysctl.d/ports.conf
• Use a reverse proxy like Traefik, Nginx to terminate TLS with a valid certificate
• Use Let’s Encrypt certificates to protect your SSL endpoints

DISCLAIMERS

• ¹ For TLS to work you need proper certificates in place for your dockerd and your clients. The CN in the certificate needs to match the FQDN or IP you have set on the docker node, you can set multiple by using SAN. See an example of a daemon.json configuration to enable TLS.

{
  "tls": true,
  "tlsverify": true,
  "tlscacert": "/etc/docker/ca.crt",
  "tlscert": "/etc/docker/server.crt",
  "tlskey": "/etc/docker/server.key",
  "hosts": ["unix:///var/run/docker.sock", "tcp://0.0.0.0:2376"]
}

ElevenNotes^™️

This image is provided to you at your own risk. Always make backups before updating an image to a new version. Check the changelog for breaking changes.