Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Internal network DNS fails to resolve #47822

Closed
ca0abinary opened this issue May 10, 2024 · 3 comments · Fixed by #47821
Closed

Internal network DNS fails to resolve #47822

ca0abinary opened this issue May 10, 2024 · 3 comments · Fixed by #47821
Labels
area/networking/dns area/networking kind/bug Bugs are bugs. The cause may or may not be known at triage time so debugging may be needed. status/0-triage version/25.0 version/26.0 version/26.1

Comments

@ca0abinary
Copy link

ca0abinary commented May 10, 2024 •
edited

Description

Moby version 25 and higher under Linux fail to correctly perform DNS resolution on internal networks using the bridge driver and DNS container option.

Reproduce

docker-compose.yaml

version: '3.8'

services:
  dns:
    image: coredns/coredns:1.11.1
    working_dir: /etc/bind
    volumes: ['./Corefile:/etc/bind/Corefile:ro']
    networks:
      isolated: { ipv4_address: 192.168.254.254 }

  web:
    image: nginx:1.25-alpine3.18
    networks:
      isolated: { ipv4_address: 192.168.254.253 }
    depends_on: [ dns ]

  test:
    init: true
    image: nginx:1.25-alpine3.18
    dns: 192.168.254.254
    networks: [isolated]
    command: [ 'sh', '-c', 'while true; do curl http://webserver.internal.net; sleep 5; done' ]
    depends_on: [ web ]

networks:
  isolated:
    name: isolated
    internal: true
    ipam:
      config:
        - subnet: 192.168.254.0/24
          ip_range: 192.168.254.0/25
          gateway: 192.168.254.1

Corefile

. {
    log
}

internal.net {
    template IN ANY {
        match .*
        answer "{{ .Name }} 60 IN A 192.168.254.253"
    }
    log
}
  1. Create above files in an empty directory
  2. Run docker compose up
    • Under v24 expect the web logs to output "Welcome to nginx!" HTML page
    • Higher versions - expect the web logs to output curl: (6) Could not resolve host: webserver.internal.net

or using dind

Failing Test:

docker run --rm -it -v $(pwd):/src --hostname docker --privileged --workdir /src --name docker-26 docker:26.1-dind
docker exec docker-26 docker compose up
# Note docker:25-dind will also fail.

Passing Test

docker run --rm -it -v $(pwd):/src --hostname docker --privileged --workdir /src --name docker-24 docker:24-dind
docker exec docker-24 docker compose up

Expected behavior

Internal DNS resolution should function identically to version 24 of Moby.

docker version

Client:
 Cloud integration: v1.0.35+desktop.13
 Version:           26.0.0
 API version:       1.45
 Go version:        go1.21.8
 Git commit:        2ae903e
 Built:             Wed Mar 20 15:16:45 2024
 OS/Arch:           linux/amd64
 Context:           default

Server: Docker Desktop
 Engine:
  Version:          26.0.0
  API version:      1.45 (minimum version 1.24)
  Go version:       go1.21.8
  Git commit:       8b79278
  Built:            Wed Mar 20 15:18:01 2024
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.6.28
  GitCommit:        ae07eda36dd25f8a1b98dfbf587313b99c0190bb
 runc:
  Version:          1.1.12
  GitCommit:        v1.1.12-0-g51d5e94
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

docker info

Client:
 Version:    26.0.0
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.11.2
    Path:     /home/jdemarks/.docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  v2.21.0
    Path:     /home/jdemarks/.docker/cli-plugins/docker-compose
  debug: Get a shell into any image or container. (Docker Inc.)
    Version:  0.0.27
    Path:     /usr/local/lib/docker/cli-plugins/docker-debug
  dev: Docker Dev Environments (Docker Inc.)
    Version:  v0.1.2
    Path:     /usr/local/lib/docker/cli-plugins/docker-dev
  extension: Manages Docker extensions (Docker Inc.)
    Version:  v0.2.23
    Path:     /usr/local/lib/docker/cli-plugins/docker-extension
  feedback: Provide feedback, right in your terminal! (Docker Inc.)
    Version:  v1.0.4
    Path:     /usr/local/lib/docker/cli-plugins/docker-feedback
  init: Creates Docker-related starter files for your project (Docker Inc.)
    Version:  v1.1.0
    Path:     /usr/local/lib/docker/cli-plugins/docker-init
  sbom: View the packaged-based Software Bill Of Materials (SBOM) for an image (Anchore Inc.)
    Version:  0.6.0
    Path:     /usr/local/lib/docker/cli-plugins/docker-sbom
  scout: Docker Scout (Docker Inc.)
    Version:  v1.6.3
    Path:     /usr/local/lib/docker/cli-plugins/docker-scout
WARNING: Plugin "/usr/local/lib/docker/cli-plugins/docker-scan" is not valid: failed to fetch metadata: fork/exec /usr/local/lib/docker/cli-plugins/docker-scan: no such file or directory

Server:
 Containers: 3
  Running: 0
  Paused: 0
  Stopped: 3
 Images: 216
 Server Version: 26.0.0
 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: cgroupfs
 Cgroup Version: 1
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: ae07eda36dd25f8a1b98dfbf587313b99c0190bb
 runc version: v1.1.12-0-g51d5e94
 init version: de40ad0
 Security Options:
  seccomp
   Profile: unconfined
 Kernel Version: 5.15.146.1-microsoft-standard-WSL2
 Operating System: Docker Desktop
 OSType: linux
 Architecture: x86_64
 CPUs: 20
 Total Memory: 15.46GiB
 Name: docker-desktop
 ID: 2fdbb658-ba61-46ad-84ab-ecbb4f49d19a
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 HTTP Proxy: http.docker.internal:3128
 HTTPS Proxy: http.docker.internal:3128
 No Proxy: hubproxy.docker.internal
 Labels:
  com.docker.desktop.address=unix:///var/run/docker-cli.sock
 Experimental: false
 Insecure Registries:
  hubproxy.docker.internal:5555
  127.0.0.0/8
 Live Restore Enabled: false

WARNING: No blkio throttle.read_bps_device support
WARNING: No blkio throttle.write_bps_device support
WARNING: No blkio throttle.read_iops_device support
WARNING: No blkio throttle.write_iops_device support
WARNING: daemon is not using the default seccomp profile

Additional Info

Independently verified in issue docker/for-win#14049
@ca0abinary ca0abinary added kind/bug Bugs are bugs. The cause may or may not be known at triage time so debugging may be needed. status/0-triage labels May 10, 2024
@ca0abinary ca0abinary mentioned this issue May 10, 2024
Closed
@thaJeztah
Copy link
Member

thaJeztah commented May 10, 2024 •
edited

I think this may be related to a security fix that fixed internal-only networks being able to access external DNS servers; GHSA-mq39-4gv4-mvpx

In this case, "external" would be the dns service, which is part of the same network, but the internal resolver likely won't take that into account; @robmry any thoughts?

@thaJeztah
Copy link
Member

Oh! Looks like a PR was opened that looks related;

@robmry
Copy link
Contributor

robmry commented May 10, 2024

Ah, yes! Thank you for re-opening this as a moby issue.

As @thaJeztah says, it's fallout from the security fix that went too far. The new PR should sort things out.

@robmry robmry mentioned this issue May 10, 2024
Merged
@vvoland vvoland mentioned this issue May 14, 2024
Merged
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
area/networking/dns area/networking kind/bug Bugs are bugs. The cause may or may not be known at triage time so debugging may be needed. status/0-triage version/25.0 version/26.0 version/26.1
Projects
None yet
Milestone
No milestone
Development

Successfully merging a pull request may close this issue.

Forward DNS requests into --internal networks robmry/moby
3 participants
@thaJeztah @ca0abinary @robmry