How to access a port on the host machine when running docker container on MacOS with --network=host?

Question

I have set up a couple of containers that interact with each other. The main application container runs on --network = host because it queries several mySQL containers running on different ports exposed on the host network.

I am trying to hit the application on the host but get an error:

curl: (7) Failed to connect to 0.0.0.0 port 36081: Connection refused

I am working on Docker installed on MacOS.

I have read several questions that indicate that docker on MacOS runs on a VM. But what is the workaround to access the application from the host? Any way to get the IP of the said VM?

Answer 1

You cannot use --network=host on Mac to connect via host ports but binding to host port using -p options works.

https://docs.docker.com/docker-for-mac/networking/#/there-is-no-docker0-bridge-on-osx

I WANT TO CONNECT TO A CONTAINER FROM THE MAC

Port forwarding works for localhost; --publish, -p, or -P all work. Ports exposed from Linux are forwarded to the host.

Our current recommendation is to publish a port, or to connect from another container. This is what you need to do even on Linux if the container is on an overlay network, not a bridge network, as these are not routed.

For your use case,

You need to create a docker network and attach both the DB and application containers to this network. Then the containers will be able to talk to each other by their name. You can also publish the application container port so that you can access it from your host.

https://docs.docker.com/network/bridge/

Instead of creating the network, attaching the containers to the network etc manually, you can use docker-compose.

https://docs.docker.com/compose/