Access host using localhost from container on MacOS

[hopoic]

Dear all,

I need to access host with localhost from container on MacOS.

1. Create container with host network mode (failed)
2. Create container with add-host "host.docker.internal:host-gateway" and access host using host.docker.internal (Failed)
3. Enable socket-vmnet

• I read https://docs.rancherdesktop.io/1.10/ui/preferences/virtual-machine/network/
• But I can't find the network settings menu in the virtual machine settings.
• I am running rancher desktop with administrative privileges, but I can't find network menu.

Does anyone know about this problem?

[vollink]

Are you looking for Port Forwarding?

[jandubois]

host.docker.internal should work even without the host-gateway setting:

❯ docker run -it --rm busybox ping host.docker.internal
Unable to find image 'busybox:latest' locally
latest: Pulling from library/busybox
559c60843878: Pull complete
Digest: sha256:498a000f370d8c37927118ed80afe8adc38d1edcbfc071627d17b25c88efcab0
Status: Downloaded newer image for busybox:latest
PING host.docker.internal (192.168.5.2): 56 data bytes
64 bytes from 192.168.5.2: seq=0 ttl=254 time=0.663 ms
64 bytes from 192.168.5.2: seq=1 ttl=254 time=0.563 ms
64 bytes from 192.168.5.2: seq=2 ttl=254 time=0.461 ms
64 bytes from 192.168.5.2: seq=3 ttl=254 time=0.562 ms
^C
--- host.docker.internal ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 0.461/0.562/0.663 ms

[grahambunce]

@jandubois I know this was nearly a year ago but this is a long standing issue I think with Rancher Desktop?

My understanding is that the ping command is pinging to the running container itself.... not the host....

i.e. my host IP is 192.168.0.90 but the host.docker.internal is resolving to 192.168.5.2

@hopoic The networking option has been removed in later versions of Rancher Desktop... not sure why... so I'm not sure myself how to get a docker container to talk to something running on my host. I think I can edit YAML files etc. but I haven't tried that yet.

[jandubois]

My understanding is that the ping command is pinging to the running container itself.... not the host....

i.e. my host IP is 192.168.0.90 but the host.docker.internal is resolving to 192.168.5.2

This is not correct. 192.168.5.2 is the gateway address to connect to the host.

Run nc -l 5555 on your host to listen on port 5555.

Then connect to it from inside a container:

❯ docker run --rm busybox sh -c 'echo foo | nc host.docker.internal 5555'

In your host shell you'll see:

❯ nc -l 5555
foo

Which proves that you are connecting to the host!