Providing both --uts=host and --network=host results in unexpected /etc/hostname

[dtantsur]

Issue Description

Normally, enabling host networking makes /etc/hostname match the real hostname of the machine where the container is running. However, adding --uts=host on top of that, resets /etc/hostname to the generated one. Illustrated:

~/P/podman (main) $ bin/podman run --rm -it centos:stream9
[root@85ab9d9e5f41 /]# uname -n
85ab9d9e5f41
[root@85ab9d9e5f41 /]# cat /etc/hostname 
85ab9d9e5f41[root@85ab9d9e5f41 /]# 
exit

~/P/podman (main) $ bin/podman run --rm -it --network=host centos:stream9
[root@dtantsur-laptop /]# uname -n
dtantsur-laptop
[root@dtantsur-laptop /]# cat /etc/hostname 
dtantsur-laptop[root@dtantsur-laptop /]# 
[root@dtantsur-laptop /]# 
exit

~/P/podman (main) $ bin/podman run --rm -it --network=host --uts=host centos:stream9
[root@dtantsur-laptop /]# uname -n
dtantsur-laptop
[root@dtantsur-laptop /]# cat /etc/hostname 
2bc6e6a91156[root@dtantsur-laptop /]# 
[root@dtantsur-laptop /]# 
exit

Steps to reproduce the issue

Steps to reproduce the issue

1. See commands in the past above

Describe the results you received

/etc/hostname contains an autogenerated host name despite both --uts=host and --network=host.

Describe the results you expected

/etc/hostname matches the output of uname -n

podman info output

host:
  arch: amd64
  buildahVersion: 1.33.0-dev
  cgroupControllers:
  - cpu
  - memory
  - pids
  cgroupManager: systemd
  cgroupVersion: v2
  conmon:
    package: conmon-2.1.7-2.fc38.x86_64
    path: /usr/bin/conmon
    version: 'conmon version 2.1.7, commit: '
  cpuUtilization:
    idlePercent: 44.44
    systemPercent: 11.2
    userPercent: 44.36
  cpus: 8
  databaseBackend: boltdb
  distribution:
    distribution: fedora
    variant: matecompiz
    version: "38"
  eventLogger: journald
  freeLocks: 2048
  hostname: dtantsur-laptop
  idMappings:
    gidmap:
    - container_id: 0
      host_id: 1000
      size: 1
    - container_id: 1
      host_id: 100000
      size: 65536
    uidmap:
    - container_id: 0
      host_id: 1000
      size: 1
    - container_id: 1
      host_id: 100000
      size: 65536
  kernel: 6.5.6-200.fc38.x86_64
  linkmode: dynamic
  logDriver: journald
  memFree: 898678784
  memTotal: 16516935680
  networkBackend: cni
  networkBackendInfo:
    backend: cni
    dns: {}
    package: containernetworking-plugins-1.3.0-2.fc38.x86_64
    path: /usr/libexec/cni
  ociRuntime:
    name: crun
    package: crun-1.9.2-1.fc38.x86_64
    path: /usr/bin/crun
    version: |-
      crun version 1.9.2
      commit: 35274d346d2e9ffeacb22cc11590b0266a23d634
      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-0^20231004.gf851084-1.fc38.x86_64
    version: |
      pasta 0^20231004.gf851084-1.fc38.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: false
    path: /run/user/1000/podman/podman.sock
  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: /usr/bin/slirp4netns
    package: slirp4netns-1.2.1-1.fc38.x86_64
    version: |-
      slirp4netns version 1.2.1
      commit: 09e31e92fa3d2a1d3ca261adaeb012c8d75a8194
      libslirp: 4.7.0
      SLIRP_CONFIG_VERSION_MAX: 4
      libseccomp: 2.5.3
  swapFree: 6367764480
  swapTotal: 8589930496
  uptime: 169h 35m 43.00s (Approximately 7.04 days)
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
  - quay.io
store:
  configFile: /home/dtantsur/.config/containers/storage.conf
  containerStore:
    number: 0
    paused: 0
    running: 0
    stopped: 0
  graphDriverName: overlay
  graphOptions:
    overlay.mount_program:
      Executable: /usr/bin/fuse-overlayfs
      Package: fuse-overlayfs-1.12-1.fc38.x86_64
      Version: |-
        fusermount3 version: 3.14.1
        fuse-overlayfs: version 1.12
        FUSE library version 3.14.1
        using FUSE kernel interface version 7.31
  graphRoot: /home/dtantsur/.local/share/containers/storage
  graphRootAllocated: 438636322816
  graphRootUsed: 349286375424
  graphStatus:
    Backing Filesystem: extfs
    Native Overlay Diff: "false"
    Supports d_type: "true"
    Supports shifting: "true"
    Supports volatile: "true"
    Using metacopy: "false"
  imageCopyTmpDir: /var/tmp
  imageStore:
    number: 186
  runRoot: /run/user/1000
  transientStore: false
  volumePath: /home/dtantsur/.local/share/containers/storage/volumes
version:
  APIVersion: 4.8.0-dev
  Built: 1698055488
  BuiltTime: Mon Oct 23 12:04:48 2023
  GitCommit: 19c870da0d4923b2bf2d62b5d424da5a649b4d40
  GoVersion: go1.21.1
  Os: linux
  OsArch: linux/amd64
  Version: 4.8.0-dev

Podman in a container

No

Privileged Or Rootless

Rootless

Upstream Latest Release

Yes

Additional environment details

Tested on my Fedora laptop based on feedback from CoreOS 8 users.

Additional information

No response

[giuseppe]

opened a PR: #20545