Re-enabling grafana deb updates / 2023-06-05

I noticed grafana hadn't updated in a while. Normally cron-apt does the prefetching of updates and notifies me when new updates are available, so I can make sure updating doesn't break running stuff or I can resolve it quick.

But cron-apt held an error message from apt update away from me which I saw by hand:

root@gosper:~# apt update
Get:1 https://packages.grafana.com/oss/deb stable InRelease [5,983 B]
Err:1 https://packages.grafana.com/oss/deb stable InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 9E439B102CF3C0C6
Get:2 http://deb.devuan.org/merged beowulf InRelease [33.5 kB]
Get:3 http://deb.devuan.org/merged beowulf-security InRelease [26.1 kB]
Get:4 http://deb.devuan.org/merged beowulf-updates InRelease [26.1 kB]
Fetched 85.7 kB in 3s (28.4 kB/s)
Reading package lists... Done
Building dependency tree
Reading state information... Done
All packages are up to date.
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://packages.grafana.com/oss/deb stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 9E439B102CF3C0C6
W: Failed to fetch https://packages.grafana.com/oss/deb/dists/stable/InRelease  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 9E439B102CF3C0C6
W: Some index files failed to download. They have been ignored, or old ones used instead.

I partly followed the instructions in Problem with debian repository key - Grafana / Installation - Grafana Labs Community Forums to get things going again. I used /etc/apt/trusted.gpg.d because this is the standard directory, is already available and the remark about ubuntu means this is the only supported directory for gpg keys.

root@gosper:~# cd /etc/apt/trusted.gpg.d/
root@gosper:/etc/apt/trusted.gpg.d# wget -q -O - https://apt.grafana.com/gpg.key  | gpg --dearmor > grafana.gpg

By putting the grafana.gpg in this directory it gets detected and used automatically. No need for a pointer in /etc/apt/sources.list.d/grafana.list.

Now apt update doesn't complain, so I will be notified of new grafana versions available.