Migrate maven exporter services to kubernetes

Those services are in charge of retrieving maven indices and create a specific parseable files exposed by a web service. Those indices are then read and parsed by the maven lister to list maven origins.

Implementation wise, currently, these are systemd services triggering docker containers to do the export.

They were not migrated [0] with the rest of the infra and are currently running in dedicated vms [1] [2].

In terms of storage [3] [4] they roughly need a storage space of 50G for both environment. We should be able to use a cephfs volume as it's only a small set of (large) files.

[0] for technical reason, we did not know yet how to properly manage volume in kubernetes. We are now able to manage those.

[1] production: maven-exporter.internal.softwareheritage.org

[2] staging: maven-exporter0.internal.staging.swh.network

[3] production ~50G of space

root@maven-exporter:~# ls -lah /var/www/maven_index_exporter
total 3.5G
drwxr-xr-x 2 root root    7 Jun 27 08:04 .
drwxr-xr-x 4 root root 4.0K Sep  8  2022 ..
-rwxrwxrwx 1 root root  442 Jun 26 20:29 export-atlassian-public.fld
-rwxrwxrwx 1 root root  63M Jun 27 08:04 export-clojars.fld
-rwxrwxrwx 1 root root  91M Jun 26 05:06 export-jboss.fld
-rwxrwxrwx 1 root root  20G Jun 26 22:22 export-maven-central.fld
-rwxrwxrwx 1 root root  20G Jun 27 04:38 export-sonatype.fld

[4] staging:

root@maven-exporter0:~# ls -lah /var/www/maven_index_exporter
total 3.2G
drwxr-xr-x 2 root root    7 Jun 27 08:09 .
drwxr-xr-x 4 root root 4.0K Apr 11  2022 ..
-rwxrwxrwx 1 root root  442 Jun 27 08:08 export-atlassian-public.fld
-rwxrwxrwx 1 root root  61M Jun 27 08:09 export-clojars.fld
-rwxrwxrwx 1 root root  91M Jun 27 08:09 export-jboss.fld
-rwxrwxrwx 1 root root  18G Jun 26 18:04 export-maven-central.fld
-rwxrwxrwx 1 root root  18G Jun 26 15:30 export-sonatype.fld