Cached metadata exists for deleted remote

[d4s]

Describe the bug I've added test remote by copying LVFS remote config file into /var/lib/fwupd/remotes.d/test-lvfs.conf, did some tests and removed configuration file for remote. Stalled metadata exists:

/var/lib/fwupd/metadata/test-lvfs:
total 940
-rw-r--r--. 1 fwupd fwupd 954615 Oct 19 06:19 metadata.xml.gz
-rw-r--r--. 1 fwupd fwupd   2236 Oct 19 06:19 metadata.xml.gz.jcat

Steps to Reproduce

1. cp /etc/fwupd/remotes.d/lvfs.conf /var/lib/fwupd/remotes.d/test-lvfs.conf
2. fwupdmgr refresh
3. rm /var/lib/fwupd/remotes.d/test-lvfs.conf

Expected behavior Metadata cached for removed remote should be wiped out.

fwupd version information

fwupdmgr --version
compile   org.freedesktop.fwupd         1.9.6
compile   com.hughsie.libxmlb           0.3.11
compile   com.hughsie.libjcat           0.1.8
compile   org.freedesktop.gusb          0.4.5
runtime   org.freedesktop.gusb          0.4.5
runtime   org.kernel                    5.15.135-20747-gb9ef44e9cff8
runtime   org.freedesktop.fwupd         1.9.6

Additional questions

• Operating system and version: ChromeOS 120
• Have you tried rebooting? Yes
• Is this a regression? No

[hughsie]

I'd much rather have a dbus call e.g. something like fwupdmgr delete-remote test-lvfs -- would that work?

[d4s]

For my purposes yes -- but since I know about the issue, I can cleanup it by my own. However it doesn't solve the issue with manual removing of the remote.conf file. How about additional check during fwupd refresh? It might be enough to remove metadata for unknown folders in /var/lib/fwupd/metadata/

[hughsie]

@superm1 how do you feel about this? I'm hesitant to delete files like this -- I don't think it's valid to have /var/lib shared on something like NFS -- but it does feel a bit magic.

[superm1]

A few thoughts

I personally feel like that /var/lib/fwupd is owned by fwupd process. Contents should only be removed if fwupd knows the remote is gone.

It might be better to put repo cache in /var/cache/fwupd.

[d4s]

Voting for /var/cache/fwupd. @hughsie additional thought -- it might be useful to check the timestamp of metadata and remove the outdated ones anyway