CODEWITHSUNDEEP
dockerdocker-compose
jpeltoniemi
jpeltoniemi

Reputation: 5620

Containers started with docker-compose inside another container are unreachable

I'm using a dedicated container for running generic project-related shell scripts in order to avoid having to test scripts on multiple environments(mac, win, ubuntu, debian...) and to minimize software requirements on the host OS. Even docker-compose commands are run from the console container. /var/run/docker.sock is bind mounted from host.

Everything else seems to be working fine, but for example if I run docker-compose up traefik inside the console container, traefik starts normally but it's unreachable both on the host and even on another container in the same network. If docker-compose up traefik is run from the host OS(Windows 10), traefik becomes reachable as expected. I suspect this has something to do with how Docker or docker-compose handle networking but I'm not completely sure. I did check that regardless of how I start the traefik container, the same ports appear instantly in NirSoft CurrPorts(sort of gui for netstat).

Is there any way (and how) to fix this?

EDIT I realised that this must be somehow an error on my part, since dockerized docker guis exist and they assumably don't have any problems bringing up containers that are accessible from the host and outside world.

Now I'm wondering if this might be a simple configuration error either in my docker(-compose) settings or somewhere else on my host machine, or do guis like Portainer go through some extra steps in order to expose the started containers to the host?

Upvotes: 0

Views: 486

Answers (1)

Karthik
Karthik

Reputation: 101

For development purpose we all map the port of Traefik to 80, so I will assume the same in your case as well. Let's assume that you are running Traefik container in a port 80 which is mapped to the port 80 in the host. But according to your Traefik container the host machine is nothing but the container which is used for running the scripts. But the port 80 of the shell script container is not mapped to the Host machine of that particular container. I hope now you have been lost somewhere around the port mapping and containers.

Let me describe your situation in the image below.enter image description here

To make your setup working you should deploy your containers as shown above along with the port mapping. To simplify the answer,

docker run -t -d -p 80:80 shellScriptImage
docker run -t -d -p 80:80 traefik (- inside the shell script container)

By doing this you can access the traefik container from the outside.

Upvotes: 1

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