podman will duplicate some of the parameters of a container executed with a systemd unit file by generating it again

[unknowndevQwQ]

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

/kind bug

Description

podman will duplicate some of the parameters of a container executed with a systemd unit file by generating it again

Steps to reproduce the issue:

1. Run the container
   # podman run --name t --rm busybox sleep 810

2. generate systemd unit files
   # podman generate systemd --files --new --name t

3. stop the container started in the first step
   # podman stop t

4. Start the container with the unit file generated in step 2
   # cp *.service -t /etc/systemd/system && systemctl start container-t

5. repeat step 2

Describe the results you received:

In the container: the --common-pidfile, --cidfile, --cgroups arguments repeat the arguments already in the previous systemd unit file on top of the podman generation
In pods: the --infra-conmon-pidfile parameter repeats the parameters of the last systemd unit file on top of those generated by podman

Describe the results you expected:

If in a container: only one podman-generated --conmon-pidfile, --cidfile, --cgroups parameter
If in a pod: only one podman-generated --infra-conmon-pidfile parameter

Additional information you deem important (e.g. issue happens only occasionally):
none
Output of podman version:

Version:      3.0.1
API Version:  3.0.0
Go Version:   go1.16
Git Commit:   c640670e85c4aaaff92741691d6a854a90229d8d
Built:        Sun Feb 21 23:29:46 2021
OS/Arch:      linux/amd64

Output of podman info --debug:

host:
  arch: amd64
  buildahVersion: 1.19.4
  cgroupManager: systemd
  cgroupVersion: v1
  conmon:
    package: /usr/bin/conmon is owned by conmon 1:2.0.26-1
    path: /usr/bin/conmon
    version: 'conmon version 2.0.26, commit: 0e155c83aa739ef0a0540ec9f9d265f57f68038b'
  cpus: 3
  distribution:
    distribution: arch
    version: unknown
  eventLogger: journald
  hostname: arch
  idMappings:
    gidmap: null
    uidmap: null
  kernel: 5.10.16-arch1-1
  linkmode: dynamic
  memFree: 1468776448
  memTotal: 6212612096
  ociRuntime:
    name: runc
    package: /usr/bin/runc is owned by runc 1.0.0rc93-1
    path: /usr/bin/runc
    version: |-
      runc version 1.0.0-rc93
      commit: 12644e614e25b05da6fd08a38ffa0cfe1903fdec
      spec: 1.0.2-dev
      go: go1.15.7
      libseccomp: 2.5.1
  os: linux
  remoteSocket:
    path: /run/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: false
    seccompEnabled: true
    selinuxEnabled: false
  slirp4netns:
    executable: ""
    package: ""
    version: ""
  swapFree: 6442442752
  swapTotal: 6442442752
  uptime: 21m 22.4s
registries: {}
store:
  configFile: /etc/containers/storage.conf
  containerStore:
    number: 5
    paused: 0
    running: 5
    stopped: 0
  graphDriverName: overlay
  graphOptions: {}
  graphRoot: /var/lib/containers/storage
  graphStatus:
    Backing Filesystem: extfs
    Native Overlay Diff: "false"
    Supports d_type: "true"
    Using metacopy: "true"
  imageStore:
    number: 31
  runRoot: /var/run/containers/storage
  volumePath: /var/lib/containers/storage/volumes
version:
  APIVersion: 3.0.0
  Built: 1613921386
  BuiltTime: Sun Feb 21 23:29:46 2021
  GitCommit: c640670e85c4aaaff92741691d6a854a90229d8d
  GoVersion: go1.16
  OsArch: linux/amd64
  Version: 3.0.1

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

Repository      : community
Name            : podman
Version         : 3.0.1-2
Description     : Tool and library for running OCI-based containers in pods
Architecture    : x86_64
URL             : https://github.com/containers/libpod
Licenses        : Apache
Groups          : None
Provides        : None
Depends On      : cni-plugins  conmon  containers-common  device-mapper  iptables  libseccomp  runc  slirp4netns  libsystemd  fuse-overlayfs  libgpgme.so=11-64
Optional Deps   : podman-docker: for Docker-compatible CLI
                  btrfs-progs: support btrfs backend devices
                  catatonit: --init flag support
                  crun: support for unified cgroupsv2
Conflicts With  : None
Replaces        : None
Download Size   : 18.65 MiB
Installed Size  : 75.64 MiB
Packager        : Morten Linderud <[email protected]>
Build Date      : Sun Feb 21 23:29:46 2021
Validated By    : MD5 Sum  SHA-256 Sum  Signature

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.):
ArchLinux on VirtualBox

[Luap99]

Why do you want to regenerate the same file when you already have a running systemd unit?
Also the new generated unit file should still be working. Specifying the same cli argument several times is valid, only the last value will be used.

[unknowndevQwQ]

Why do you want to regenerate the same file when you already have a running systemd unit?
Also the new generated unit file should still be working. Specifying the same cli argument several times is valid, only the last value will be used.

I only updated the scripts that podman 2.0.4 generated

[Luap99]

This makes sense. We already check for the --name flag so checking for other flags should be easy.

[unknowndevQwQ]

This makes sense. We already check for the --name flag so checking for other flags should be easy.

wdym

[Luap99]

I was wondering why you would want to do this. Updating the files after a podman upgrade sounds reasonable to me.
We have already a check in the generating code for the --name and --replace flag so adding the flags you mentioned should only need a small change to the code.