/etc/hosts duplicated every time after container restarted

[changsijay]

Is this a BUG REPORT or FEATURE REQUEST? (leave only one on its own line)

/kind bug

Description

/etc/hosts duplicated every time when container restarted

Steps to reproduce the issue:

sudo podman pod create --name demo-pod
sudo podman run --name=demo-container --detach --restart=always --pod=demo-pod nginx
sudo podman exec -it demo-container cat /etc/hosts | grep demo-container | wc
# get 1

sudo podman restart demo-container
sudo podman exec -it demo-container cat /etc/hosts | grep demo-container | wc
# get 2

sudo podman restart demo-container
sudo podman exec -it demo-container cat /etc/hosts | grep demo-container | wc
# get 3

Describe the results you received:

/etc/hosts keep duplicating 127.0.1.1 demo-pod demo-container after I restart demo-container

Describe the results you expected:

127.0.1.1 demo-pod demo-container should not duplicated in /etc/hosts

Additional information you deem important (e.g. issue happens only occasionally):

Output of podman version:

Version:      2.2.1
API Version:  2.1.0
Go Version:   go1.15.6
Git Commit:   a0d478edea7f775b7ce32f8eb1a01e75374486cb
Built:        Wed Dec  9 04:48:23 2020
OS/Arch:      linux/amd64

Output of podman info --debug:

host:
  arch: amd64
  buildahVersion: 1.18.0
  cgroupManager: cgroupfs
  cgroupVersion: v1
  conmon:
    package: Unknown
    path: /usr/bin/conmon
    version: 'conmon version 2.0.22, commit: 9c34a8663b85e479e0c083801e89a2b2835228ed'
  cpus: 4
  distribution:
    distribution: arch
    version: unknown
  eventLogger: journald
  hostname: Macmini
  idMappings:
    gidmap:
    - container_id: 0
      host_id: 1000
      size: 1
    uidmap:
    - container_id: 0
      host_id: 1000
      size: 1
  kernel: 5.10.5-arch1-1
  linkmode: dynamic
  memFree: 10837921792
  memTotal: 16686837760
  ociRuntime:
    name: runc
    package: Unknown
    path: /usr/bin/runc
    version: |-
      runc version 1.0.0-rc92
      commit: ff819c7e9184c13b7c2607fe6c30ae19403a7aff
      spec: 1.0.2-dev
  os: linux
  remoteSocket:
    path: /run/user/1000/podman/podman.sock
  rootless: true
  slirp4netns:
    executable: /usr/bin/slirp4netns
    package: Unknown
    version: |-
      slirp4netns version 1.1.8
      commit: d361001f495417b880f20329121e3aa431a8f90f
      libslirp: 4.4.0
      SLIRP_CONFIG_VERSION_MAX: 3
      libseccomp: 2.5.1
  swapFree: 0
  swapTotal: 0
  uptime: 51h 50m 10.73s (Approximately 2.12 days)
registries:
  search:
  - docker.io
store:
  configFile: /home/csj/.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: Unknown
      Version: |-
        fusermount3 version: 3.10.1
        fuse-overlayfs: version 1.3
        FUSE library version 3.10.1
        using FUSE kernel interface version 7.31
  graphRoot: /home/csj/.local/share/containers/storage
  graphStatus:
    Backing Filesystem: extfs
    Native Overlay Diff: "false"
    Supports d_type: "true"
    Using metacopy: "false"
  imageStore:
    number: 0
  runRoot: /run/user/1000/containers
  volumePath: /home/csj/.local/share/containers/storage/volumes
version:
  APIVersion: 2.1.0
  Built: 1607464103
  BuiltTime: Wed Dec  9 04:48:23 2020
  GitCommit: a0d478edea7f775b7ce32f8eb1a01e75374486cb
  GoVersion: go1.15.6
  OsArch: linux/amd64
  Version: 2.2.1

Package info (e.g. output of rpm -q podman or apt list podman):

podman 2.2.1-1

Have you tested with the latest version of Podman and have you checked the Podman Troubleshooting Guide?

Yes

Additional environment details (AWS, VirtualBox, physical, etc.):