docker/cli

`--add-host` not working

codemeleon opened this issue · 4 comments

codemeleon commented

Contributing guidelines

I've found a bug and checked that ...

  • ... the documentation does not mention anything about my problem
  • ... there are no open or closed issues that are related to my problem

Description

I have two servers with the same operating system (OS: Ubuntu 22.04.5 LTS x86_64) and both run Docker (Docker version 24.0.7, build 24.0.7-0ubuntu2~22.04.1). I'm trying to access host web-services from inside a container. I followed the instructions from https://docs.docker.com/reference/cli/docker/container/run/#add-host and used the "hello from host" example. On one system, it works; however, on another server, it fails to access the web-server.

Expected behaviour

$docker run \
  --add-host=host.docker.internal:host-gateway \
  curlimages/curl -s host.docker.internal:8000/hello

hello from host!

Actual behaviour

$docker run \
  --add-host=host.docker.internal:host-gateway \
  curlimages/curl -s host.docker.internal:8000/hello

Buildx version

github.com/docker/buildx 0.12.1 0.12.1-0ubuntu2.1

Docker info

Client:
 Version:    24.0.7
 Context:    default
 Debug Mode: false

Server:
 Containers: 88
  Running: 0
  Paused: 0
  Stopped: 88
 Images: 26
 Server Version: 24.0.7
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Using metacopy: false
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: systemd
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 
 runc version: 
 init version: 
 Security Options:
  apparmor
  seccomp
   Profile: builtin
  cgroupns
 Kernel Version: 5.15.0-119-generic
 Operating System: Ubuntu 22.04.5 LTS
 OSType: linux
 Architecture: x86_64
 CPUs: 2
 Total Memory: 7.746GiB
 Name: beamish
 ID: dc8ba74f-07f6-4561-a227-ed950578027c
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false

Builders list

NAME/NODE DRIVER/ENDPOINT STATUS BUILDKIT PLATFORMS
default * docker
default default running v0.11.7+d3e6c1360f6e linux/amd64, linux/amd64/v2, linux/386

Configuration

NA

Build logs

No response

Additional info

No response

crazy-max commented

This repo is about buildx cli plugin, I think you're alooking for support in https://github.com/docker/cli repo, let me move this issue there.

thaJeztah commented

Moved to docker/cli, but we may need more information;

@codemeleon what does the output of this command give in both your systems?

docker run --rm --add-host=host.docker.internal:host-gateway alpine sh -c 'cat /etc/hosts | grep host.docker.internal'

When run, that should output the IP-address you configured in daemon configuration to be set in the container's /etc/hosts entries, for example;

$ docker run --rm --add-host=host.docker.internal:host-gateway alpine sh -c 'cat /etc/hosts | grep host.docker.internal'

192.168.65.254	host.docker.internal

If that works, the feature itself works, but it's possible that networking or iptables rules on your system prevents the container from connecting.

  • 👍1
codemeleon commented

Hi @thaJeztah ,
Many thanks for your response and moving my query to the right repository.

You are correct, ufw was blocking access to the host service from Docker. I followed instructions from https://superuser.com/questions/1709013/enable-access-to-host-service-with-ubuntu-firewall-from-docker-container. It has resolved the issue.

Thank you again.

thaJeztah commented

Good to hear you managed to resolve it!