docker-compose creates wrong resolv.conf

[derkoe]

When I use docker-compose (from Windows or WSL), the generated resolv.conf is wrong which results in a broken DNS.
When I run the image directly with the Docker client everything works as expected.

With docker run the /etc/resolv.conf is:

nameserver 172.21.97.50

With docker-compose the /etc/resolv.conf is:

nameserver 127.0.0.11
options ndots:0

This is how you can reproduce it:

❯ docker run -it --rm postgres:16-alpine cat /etc/resolv.conf
nameserver 172.21.97.50

❯ cat docker-compose.yml
version: "3"
services:
  database:
    image: postgres:16-alpine
    command: cat /etc/resolv.conf

❯ docker-compose up
Creating network "tmp_default" with the default driver
Creating tmp_database_1 ... done
Attaching to tmp_database_1
database_1  | nameserver 127.0.0.11
database_1  | options ndots:0
tmp_database_1 exited with code 0

My Rancher Desktop version is 1.12.3

[derkoe]

Just found out that docker-compose is using a separate dns server (mostly 127.0.0.11). So that is not the issue. It seemst to be related to the bridged network