Docker 容器无法解析 docker 主机可以解析的互联网主机

Question

This confuses me as it's just started happening...

My workstation (Ubuntu 18.04 running docker 20.10.17) can resolve a specific internet host without issue. The container that my workstation hosts, however, is unable to resolve the same host.

Any other internet host appears to resolve without any issue within the container: actually, from what I can see, it's unable to resolve any host assigned to that specific domain name (eg flora.com) but only in the container - on the host it's just fine.

I've read that docker takes a copy of /etc/resolv.conf from the host and places it into the container, but I don't think that's correct as my container's /etc/resolv.conf reads as follows:

search lan
nameserver 127.0.0.11
options edns0 ndots:0

whereas my workstation's /etc/resolv.conf read:

# This file is managed by man:systemd-resolved(8). Do not edit.
...
# operation for /etc/resolv.conf.

nameserver 127.0.0.53
options edns0
search lan

Within my docker-compose.yml I have my containers using a defined bridged network (which has been working just fine for the last three years):

  console-vpacs:
    ...
    depends_on: [console-mysql]
    ...
    networks:
      - dev-vlt-console
...
networks:
  dev-vlt-console:
    name: dev-vlt-console
    driver: bridge

I'm at a bit of a loss where to go from here as I've:

1. restarted the docker service a number of time
2. deleted the docker0 interface, restarted the service
3. searched SO and google and nothing appears to be working (the only thing I've not done is to remove docker and reinstall)

Can anyone give any insight?

Answer 1

A complete reinstall of docker resolved this issue. Very odd that it happened, but I'm still running 20.10.17 so there was no update there... but I'm back up and running again