Gotthard

A container that exposes remote ports to your containers via ssh local forwarding. The container will try to use all files in the folder that is mounted on /root/.ssh/ to authenticate. Mounting single files, will not work, as docker volume mounting only works on folders.

⚠️ If your SSH key requires a passphrase, please specify it using SSH_KEY_PASSPHRASE environment variable.

It is also possible to use jump hosts:

• Specify the desired jump host(s) the following way (as value of JUMP_HOSTS):
  • JUMP_USER@JUMP_HOST
  • JUMP_USER1@JUMP_HOST1,JUMP_USER2@JUMP_HOST2

Examples

Suppose we want to expose PORT 8080 and 8081 to the containers in our network.

bash:

docker run \
  -v ~/.ssh/:/root/.ssh/ \
  -p 8080:8080 \
  -p 8081:8081 \
  -e USER=florian \
  -e JUMP_HOSTS=user1@my.jumphost.example.org,user3@my.other.jumphost.example.org
  -e HOST=example.org \
  -e PORTS=80:8080,81:8081  \
  stocard/gotthard

Suppose we want to expose PORT 8080 and 8081 of host my.endhost.example.org, which is reachable by the host example.org, to the containers in our network.

bash:

docker run \
  -v ~/.ssh/:/root/.ssh/ \
  -p 8080:8080 \
  -p 8081:8081 \
  -e USER=florian \
  -e JUMP_HOSTS=user1@my.jumphost.example.org,user3@my.other.jumphost.example.org
  -e HOST=example.org \
  -e HOSTS_AND_PORTS=80:my.endhost.example.org:8080,81:my.endhost.example.org:8081  \
  stocard/gotthard

You could also combine both approaches:

docker run \
  -v ~/.ssh/:/root/.ssh/ \
  -p 8080:8080 \
  -p 8081:8081 \
  -e USER=florian \
  -e JUMP_HOSTS=user1@my.jumphost.example.org,user3@my.other.jumphost.example.org
  -e HOST=example.org \
  -e PORTS=80:8080,81:8081  \
  -e HOSTS_AND_PORTS=82:my.endhost.example.org:8082,83:my.endhost.example.org:8083  \
  stocard/gotthard

This forwards port 80 and 81 from the Host and 82 and 83 from my.endhost.example.org.

docker-compose:

services:
  (...)
  gotthard:
    image: stocard/gotthard
    environment: 
      - USER=user
      - HOST=example.org
      - JUMP_HOSTS=user@my.jump_host.example.org
      - PORTS=80:8080,81:8081
    volumes:
      - ~/.ssh/:/root/.ssh/

Your containers can now use gotthard:80 or gotthard:81 to talk to the remote server.

services:
  (...)
  gotthard:
    image: stocard/gotthard
    environment: 
      - USER=user
      - HOST=example.org
      - JUMP_HOSTS=user@my.jump_host.example.org
      - PORTS=80:8080,81:8081
      - HOSTS_AND_PORTS=82:my.endhost.example.org:8082,83:my.endhost.example.org:8083
    volumes:
      - ~/.ssh/:/root/.ssh/

Your containers can now use gotthard:80, gotthard:81, gotthard:82 or gotthard:83 to talk to the remote server.