host.containers.internal not accessible on podman native

[axel7083]

Issue Description

Using podman native on linux, I am not able to use host.containers.internal:<exposed-container-port> to ping other containers.

If I am using a qemu machine, this is working well.

I've not found much documentation on host.containers.internal so this might be the expected behaviour.

Steps to reproduce the issue

Steps to reproduce the issue

1. Start an nginx container podman run --name nginx-demo -d -p 8080:80 nginx
2. Run podman run --rm docker.io/curlimages/curl -v host.containers.internal:8080
3. assert logs Could not resolve host: host.containers.internal

Describe the results you received

curl: (6) Could not resolve host: host.containers.internal

Describe the results you expected

<h1>Welcome to nginx!</h1>

podman info output

host:
arch: amd64
buildahVersion: 1.37.3
cgroupControllers:

• cpu
• io
• memory
• pids
  cgroupManager: systemd
  cgroupVersion: v2
  conmon:
  package: conmon-2.1.12-2.fc40.x86_64
  path: /usr/bin/conmon
  version: 'conmon version 2.1.12, commit: '
  cpuUtilization:
  idlePercent: 91.54
  systemPercent: 0.96
  userPercent: 7.5
  cpus: 16
  databaseBackend: sqlite
  distribution:
  distribution: fedora
  variant: workstation
  version: "40"
  eventLogger: journald
  freeLocks: 2026
  hostname: Host-005
  idMappings:
  gidmap:
  • container_id: 0
    host_id: 1000
    size: 1
  • container_id: 1
    host_id: 524288
    size: 65536
    uidmap:
  • container_id: 0
    host_id: 1000
    size: 1
  • container_id: 1
    host_id: 524288
    size: 65536
    kernel: 6.10.12-200.fc40.x86_64
    linkmode: dynamic
    logDriver: journald
    memFree: 22461300736
    memTotal: 67111100416
    networkBackend: netavark
    networkBackendInfo:
    backend: netavark
    dns:
    package: aardvark-dns-1.12.2-2.fc40.x86_64
    path: /usr/libexec/podman/aardvark-dns
    version: aardvark-dns 1.12.2
    package: netavark-1.12.2-1.fc40.x86_64
    path: /usr/libexec/podman/netavark
    version: netavark 1.12.2
    ociRuntime:
    name: crun
    package: crun-1.17-1.fc40.x86_64
    path: /usr/bin/crun
    version: |-
    crun version 1.17
    commit: 000fa0d4eeed8938301f3bcf8206405315bc1017
    rundir: /run/user/1000/crun
    spec: 1.0.0
    +SYSTEMD +SELINUX +APPARMOR +CAP +SECCOMP +EBPF +CRIU +LIBKRUN +WASM:wasmedge +YAJL
    os: linux
    pasta:
    executable: /usr/bin/pasta
    package: passt-0^20240906.g6b38f07-1.fc40.x86_64
    version: |
    pasta 0^20240906.g6b38f07-1.fc40.x86_64
    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: /run/user/1000/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: false
    slirp4netns:
    executable: ""
    package: ""
    version: ""
    swapFree: 8589930496
    swapTotal: 8589930496
    uptime: 21h 43m 18.00s (Approximately 0.88 days)
    variant: ""
    plugins:
    authorization: null
    log:
• k8s-file
• none
• passthrough
• journald
  network:
• bridge
• macvlan
• ipvlan
  volume:
• local
  registries:
  search:
• registry.fedoraproject.org
• registry.access.redhat.com
• docker.io
  store:
  configFile: /home/axel7083/.config/containers/storage.conf
  containerStore:
  number: 21
  paused: 0
  running: 1
  stopped: 20
  graphDriverName: overlay
  graphOptions: {}
  graphRoot: /home/axel7083/.local/share/containers/storage
  graphRootAllocated: 1022505254912
  graphRootUsed: 324359106560
  graphStatus:
  Backing Filesystem: btrfs
  Native Overlay Diff: "true"
  Supports d_type: "true"
  Supports shifting: "false"
  Supports volatile: "true"
  Using metacopy: "false"
  imageCopyTmpDir: /var/tmp
  imageStore:
  number: 362
  runRoot: /run/user/1000/containers
  transientStore: false
  volumePath: /home/axel7083/.local/share/containers/storage/volumes
  version:
  APIVersion: 5.2.3
  Built: 1727136000
  BuiltTime: Tue Sep 24 02:00:00 2024
  GitCommit: ""
  GoVersion: go1.22.7
  Os: linux
  OsArch: linux/amd64
  Version: 5.2.3

Podman in a container

No

Privileged Or Rootless

Rootless

Upstream Latest Release

No

Additional environment details

podman native linux

Additional information

Works fine with qemu

1. Start webserver podman --connection=podman-machine-default run --name nginx-demo-qemu -d -p 8080:80 nginx
2. Run podman --connection=podman-machine-default run --rm docker.io/curlimages/curl -v host.containers.internal:8080
3. assert <h1>Welcome to nginx!</h1>

[Luap99]

you need a second host ip with pasta or wait for podman v5.3 (#24133 (comment)) or you use --network sirp4netns for now.

There is some more discussion in #22653

[axel7083]

Thanks @Luap99 for the fast reply and the details 👍