Fixes #38236 - copy /run/containers/0/auth.json only if it exists

[pmoravec]

What are the changes introduced in this pull request?

Don't fail on copy /run/containers/0/auth.json to /etc/flatpak/oci-auth.json if the source file does not exist - its presence is optional.

Considerations taken when implementing this change?

There are a few options how to fix this, i.e. redirect stderr to /dev/null. I chose this cp option:

   -u, --update
          copy only when the SOURCE file is newer than the destination file or when the destination file is missing

for its positive side-effect: dont overwrite oci-auth.json if it has a newer content (at least I see this as a feature and not a bug of the chosen fix - let me see if you think otherwise).

What are the testing steps for this pull request?

Ensure no /run/containers/0/auth.json is present on a Host with podman and flatpak (this is default), and apply the job template to the Host.

[ianballou]

I haven't tested this via REX yet, but does it work in practice? Seeing this on the shell:

[root@9 ~]# cat /run/containers/0/auth.json 
cat: /run/containers/0/auth.json: No such file or directory
[root@9 ~]# sudo cp --update /run/containers/0/auth.json /etc/flatpak/oci-auth.json
cp: cannot stat '/run/containers/0/auth.json': No such file or directory
[root@9 ~]# echo $?
1

It looks like the return code is still 1 if the source exists, which should fail the REX job.

I suppose an alternate solution could be to use test:

if test -f "/run/containers/0/auth.json"; then
  sudo cp --update /run/containers/0/auth.json /etc/flatpak/oci-auth.json
fi

[ianballou]

I tested it just to be safe and saw this:

   1:
Login Succeeded!
   2:
cp: cannot create regular file '/etc/flatpak/oci-auth.json': No such file or directory
   3:
Exit status: 1
   4:
StandardError: Job execution failed

Edit: this occurred because flatpak wasn't installed yet. The dir should exist if flatpak is installed.

[ianballou]

I'm confused how /run/containers/0/auth.json would not exist, it gets populated when you podman login. Unless podman can be configured to not create the file?

[ianballou]

Testing with the current changes and flatpak installed, I see:

   1:
cp: cannot stat '/run/containers/0/auth.json': No such file or directory
   2:
Exit status: 1
   3:
StandardError: Job execution failed

Testing with the if statement added (described above) lets the job succeed.

[ianballou]

Suggested change

	sudo cp --update /run/containers/0/auth.json /etc/flatpak/oci-auth.json
	if test -f "/run/containers/0/auth.json"; then
	sudo cp --update /run/containers/0/auth.json /etc/flatpak/oci-auth.json
	fi