Setting DNS of a container does not work in docker-compose

[abdsahin]

Issue Description

I am trying to make the example about accessing localstack via endpoint url which needs to set one of the containers in the compose services as the default dns. I used rootfull, rootless containers also used docker-compose and podman-compose but non of them worked so far.

I can see the DNS setting when I inspect the pod, but DNS queries still goes to 10.0.2.1

podman version 5.6.2
Docker Compose version 2.40.3
limactl version 2.0.1
macOS - 15.7.1

Steps to reproduce the issue

Steps to reproduce the issue

1. Use the docker-compose file here
2. Use docker-compose or podman-compose
3. Try to resolve localhost.localstack.cloud from the second container

Describe the results you received

Container is still using 10.0.2.1 for DNS resolutions

Describe the results you expected

Container is still using 10.0.2.20 for DNS resolutions

podman info output

Client:
  APIVersion: 5.6.0
  BuildOrigin: pkginstaller
  Built: 1755272543
  BuiltTime: Fri Aug 15 17:42:23 2025
  GitCommit: da671ef6cfa3fc9ac6225c18f1dd0a70a951e43f
  GoVersion: go1.25.0
  Os: darwin
  OsArch: darwin/arm64
  Version: 5.6.0
host:
  arch: arm64
  buildahVersion: 1.41.5
  cgroupControllers:
  - cpu
  - io
  - memory
  - pids
  cgroupManager: systemd
  cgroupVersion: v2
  conmon:
    package: conmon-2.1.13-1.fc42.aarch64
    path: /usr/bin/conmon
    version: 'conmon version 2.1.13, commit: '
  cpuUtilization:
    idlePercent: 98.5
    systemPercent: 0.54
    userPercent: 0.96
  cpus: 4
  databaseBackend: sqlite
  distribution:
    distribution: fedora
    variant: coreos
    version: "42"
  emulatedArchitectures:
  - linux/386
  - linux/amd64
  - linux/arm64be
  eventLogger: journald
  freeLocks: 2038
  hostname: localhost.localdomain
  idMappings:
    gidmap:
    - container_id: 0
      host_id: 1000
      size: 1
    - container_id: 1
      host_id: 100000
      size: 1000000
    uidmap:
    - container_id: 0
      host_id: 501
      size: 1
    - container_id: 1
      host_id: 100000
      size: 1000000
  kernel: 6.15.10-200.fc42.aarch64
  linkmode: dynamic
  logDriver: journald
  memFree: 1350823936
  memTotal: 3788349440
  networkBackend: netavark
  networkBackendInfo:
    backend: netavark
    dns:
      package: aardvark-dns-1.16.0-1.fc42.aarch64
      path: /usr/libexec/podman/aardvark-dns
      version: aardvark-dns 1.16.0
    package: netavark-1.16.1-1.fc42.aarch64
    path: /usr/libexec/podman/netavark
    version: netavark 1.16.1
  ociRuntime:
    name: crun
    package: crun-1.23.1-1.fc42.aarch64
    path: /usr/bin/crun
    version: |-
      crun version 1.23.1
      commit: d20b23dba05e822b93b82f2f34fd5dada433e0c2
      rundir: /run/user/501/crun
      spec: 1.0.0
      +SYSTEMD +SELINUX +APPARMOR +CAP +SECCOMP +EBPF +CRIU +LIBKRUN +WASM:wasmedge +YAJL
  os: linux
  pasta:
    executable: /usr/sbin/pasta
    package: passt-0^20250805.g309eefd-2.fc42.aarch64
    version: |
      pasta 0^20250805.g309eefd-2.fc42.aarch64-pasta
      Copyright Red Hat
      GNU General Public License, version 2 or later
        <https://www.gnu.org/licenses/old-licenses/gpl-2.0.html>
      This is free software: you are free to change and redistribute it.
      There is NO WARRANTY, to the extent permitted by law.
  remoteSocket:
    exists: true
    path: unix:///run/user/501/podman/podman.sock
  rootlessNetworkCmd: pasta
  security:
    apparmorEnabled: false
    capabilities: CAP_CHOWN,CAP_DAC_OVERRIDE,CAP_FOWNER,CAP_FSETID,CAP_KILL,CAP_NET_BIND_SERVICE,CAP_SETFCAP,CAP_SETGID,CAP_SETPCAP,CAP_SETUID,CAP_SYS_CHROOT
    rootless: true
    seccompEnabled: true
    seccompProfilePath: /usr/share/containers/seccomp.json
    selinuxEnabled: true
  serviceIsRemote: true
  slirp4netns:
    executable: /usr/sbin/slirp4netns
    package: slirp4netns-1.3.1-2.fc42.aarch64
    version: |-
      slirp4netns version 1.3.1
      commit: e5e368c4f5db6ae75c2fce786e31eef9da6bf236
      libslirp: 4.8.0
      SLIRP_CONFIG_VERSION_MAX: 5
      libseccomp: 2.5.5
  swapFree: 0
  swapTotal: 0
  uptime: 1h 46m 23.00s (Approximately 0.04 days)
  variant: v8
plugins:
  authorization: null
  log:
  - k8s-file
  - none
  - passthrough
  - journald
  network:
  - bridge
  - macvlan
  - ipvlan
  volume:
  - local
registries:
  search:
  - docker.io
store:
  configFile: /var/home/core/.config/containers/storage.conf
  containerStore:
    number: 5
    paused: 0
    running: 5
    stopped: 0
  graphDriverName: overlay
  graphOptions: {}
  graphRoot: /var/home/core/.local/share/containers/storage
  graphRootAllocated: 99252940800
  graphRootUsed: 5448122368
  graphStatus:
    Backing Filesystem: xfs
    Native Overlay Diff: "true"
    Supports d_type: "true"
    Supports shifting: "false"
    Supports volatile: "true"
    Using metacopy: "false"
  imageCopyTmpDir: /var/tmp
  imageStore:
    number: 2
  runRoot: /run/user/501/containers
  transientStore: false
  volumePath: /var/home/core/.local/share/containers/storage/volumes
version:
  APIVersion: 5.6.2
  BuildOrigin: 'Copr: packit/containers-podman-27198'
  Built: 1759190400
  BuiltTime: Tue Sep 30 02:00:00 2025
  GitCommit: 9dd5e1ed33830612bc200d7a13db00af6ab865a4
  GoVersion: go1.24.7
  Os: linux
  OsArch: linux/arm64
  Version: 5.6.2

Podman in a container

No

Privileged Or Rootless

Rootless

Upstream Latest Release

Yes

Additional environment details

Additional environment details

Additional information

Additional information like issue happens only occasionally or issue happens with a particular architecture or on a particular setting