A dynamic docker->redis->traefik discovery agent.
Solves the problem of running a non-Swarm/Kubernetes multi-host cluster with a single public-facing traefik instance.
+---------------------+ +---------------------+
| | | |
+---------+ :443 | +---------+ | :8088 | +------------+ |
| WAN |--------------->| traefik |<-------------------->| svc-nginx | |
+---------+ | +---------+ | | +------------+ |
| | | | |
| +---------+ | | +-------------+ |
| | redis |<-------------------->| traefik-kop | |
| +---------+ | | +-------------+ |
| docker1 | | docker2 |
+---------------------+ +---------------------+
traefik-kop
solves this problem by using the same traefik
docker-provider
logic. It reads the container labels from the local docker node and publishes
them to a given redis
instance. Simply configure your traefik
node with a
redis
provider and point it to the same instance, as in the diagram above.
Configure traefik
to use the redis provider, for example via traefik.yml
:
providers:
providersThrottleDuration: 2s
docker:
watch: true
endpoint: unix:///var/run/docker.sock
swarmModeRefreshSeconds: 15s
exposedByDefault: false
redis:
endpoints:
# assumes a redis link with this service name running on the same
# docker host as traefik
- "redis:6379"
Run traefik-kop
on your other nodes via docker-compose:
version: "3"
services:
traefik-kop:
image: "ghcr.io/jittering/traefik-kop:latest"
restart: unless-stopped
volumes:
- /var/run/docker.sock:/var/run/docker.sock
environment:
- "REDIS_ADDR=192.168.1.50:6379"
- "BIND_IP=192.168.1.75"
Then add labels to your target service:
services:
nginx:
image: "nginx:alpine"
restart: unless-stopped
ports:
- 8088:80
labels:
- "traefik.enable=true"
- "traefik.http.routers.nginx.rule=Host(`nginx-on-docker2.example.com`)"
- "traefik.http.routers.nginx.tls=true"
- "traefik.http.routers.nginx.tls.certresolver=default"
- "traefik.http.services.nginx.loadbalancer.server.scheme=http"
- "traefik.http.services.nginx.loadbalancer.server.port=8088"
NOTE: unlike the standard traefik-docker usage, we need to expose the service port on the host and tell traefik to bind to that port (8088 in the example above) in the load balancer config, not the internal port. This is so that traefik can reach it over the network.
See also bind-ip section below.
traefik-kop can be configured via either CLI flags are environment variables.
USAGE:
traefik-kop [global options] command [command options] [arguments...]
GLOBAL OPTIONS:
--hostname value Hostname to identify this node in redis (default: "culture.local") [$KOP_HOSTNAME]
--bind-ip value IP address to bind services to (default: "192.168.80.99") [$BIND_IP]
--redis-addr value Redis address (default: "127.0.0.1:6379") [$REDIS_ADDR]
--redis-pass value Redis password (if needed) [$REDIS_PASS]
--redis-db value Redis DB number (default: 0) [$REDIS_DB]
--verbose Enable debug logging (default: false) [$VERBOSE, $DEBUG]
--help, -h show help (default: false)
Most important are the bind-ip
and redis-addr
flags.
Since your upstream docker nodes are external to your primary traefik server, traefik needs to connect to these services via the server's public IP rather than the usual method of using the internal docker-network IPs (by default 172.20.0.x or similar).
When using host networking this can be auto-detected, however it is advisable in
the majority of cases to manually set this to the desired IP address. This can
be done using the docker image by exporting the BIND_IP
environment variable.
traefik-kop expects to connect to the Docker host API via unix socket at
/var/run/docker.sock
. Other connection methods (like ssh, http/s) are not
supported.
traefik-kop: MIT, (c) 2021, Pixelcop Research, Inc.
traefik: MIT, (c) 2016-2020 Containous SAS; 2020-2021 Traefik Labs