Description of problem:
Ceph exporter does not implement properly SIGTERM and SIGINT signals exiting with an error when these signals are sent to the Ceph exporter.



Version-Release number of selected component (if applicable):
ceph 8.0

How reproducible:

Example:
terminal A ==========
$ ./ceph-exporter c /home/jolmomar/Code/ceph/build/ceph.conf --sock-dir /home/jolmomar/Code/ceph/build/asok
2024-10-23T12:37:54.538+0200 7f1c4fe990c0 -1 WARNING: all dangerous and experimental features are enabled.
2024-10-23T12:37:54.543+0200 7f1c4fe990c0 -1 WARNING: all dangerous and experimental features are enabled.
2024-10-23T12:37:54.543+0200 7f1c4fe990c0 -1 WARNING: all dangerous and experimental features are enabled.
system:0
...
system:0
Terminated
$ echo $?
143 <--- 128 + 15(SIGTERM)

terminal B ==========
$ ps ef | grep exporter
jolmomar 116727 105597 1 12:37 pts/1 00:00:00 ./ceph-exporter -c /home/jolmomar/Code/ceph/build/ceph.conf --sock-dir /home/jolmomar/Code/ceph/build/asok
jolmomar 116812 109376 0 12:38 pts/2 00:00:00 grep --color=auto exporter
jolmomar:~/.../build/bin$ kill -15 116727 <--- SEND SIGTERM

Steps to Reproduce:
1. launch Ceph exporter
2. terminate Ceph exporter sending SIGTERM/SIGINT signals
3. Check process exit status is different from 0

Also possible to test, stopping the exporter service/or ceph exporter daemons using orchestrator commands example: "ceph orch stop exporter"
After execution the stop command, the ceph exporter will appear in the list of services or daemons with status "error"

Actual results:
Exit status different from 0 when SIGINT/SIGTERM signals are sent to the process.
"Ceph orch stop" command does not produce ceph exporter daemon/service with "error" status.

Expected results:
when sent SIGTERM/SIGINT, process exit code must be 0

Additional info: