hugojosefson/redirect-to-host

Redirects incoming TCP connections to Docker host.

Meant to be used in a docker stack as temporary replacement for a service you wish to develop and run locally on the host.

The other services in the stack can continue try to access the service like normal, and the requests will be forwarded up to the host.

Make sure the service you are developing listens on 0.0.0.0 with the relevant port. Then if it needs to contact the other services, make sure their ports are published, so they can be accessed on localhost from the service running on the host.

Example usage with docker swarm

Given *.local.example.com is registered in DNS as 127.0.0.1.

In the docker-compose.yml file, where you want to replace example-backend with redirect-to-host so you can develop and run example-backend in your IDE on the host:

version: "3.7"

networks:
  traefik-net: {}

services:
  traefik:
    image: traefik
    command: --docker --docker.swarmMode --docker.watch
      --docker.domain=local.example.com --api
    ports:
      - 80:80
      - 8080:8080
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    deploy:
      mode: global
      placement:
        constraints:
          - node.role == manager
    networks:
      - traefik-net

  example-backend:
    image: hugojosefson/redirect-to-host
    deploy:
      replicas: 1
      labels:
        traefik.port: 10100
        traefik.frontend.rule: Host:example-backend.local.example.com
    environment:
      PORT: 10100
    networks:
      - traefik-net

  example-frontend:
    image: docker-registry.example.com/example-frontend:master
    deploy:
      replicas: 1
      labels:
        traefik.port: 10200
        traefik.frontend.rule: Host:example-frontend.local.example.com
    environment:
      API_ROOT: http://example-backend.local.example.com/api/v1
      PORT: 10200
    networks:
      - traefik-net

  example-other-service:
    image: docker-registry.example.com/example-other-service:master
    deploy:
      replicas: 1
      labels:
        traefik.port: 10300
        traefik.frontend.rule: Host:example-other-service.local.example.com
    environment:
      PORT: 10300
    networks:
      - traefik-net

You may then deploy the stack:

docker stack deploy \
  --with-registry-auth \
  --prune \
  --compose-file docker-compose.yml \
  thestack

In this example, example-frontend will be able to connect to the example-backend you run in development mode on the host. It will then be able to access example-other-service on http://example-other-service.local.example.com.