Manual migrations

Normally the most of migrations are handled automatically after application start, however, some upgrades require manual interventions; this document describes them.

Upgrades to breakpoints

To 2.9.0

This release includes major upgrade for the newest devtools and archlinux repository structure. In order to upgrade package need to:

Upgrade to the latest major release of python (3.11) (required by other changes).
Upgrade devtools to the latest release.
Backup local settings, /etc/ahriman.ini.d/00-setup-overrides.ini by default.
Run setup command (i.e. ahriman service-setup) again with the same arguments as used before. This step can be done manually by moving devtools configuration (something like /usr/share/devtools/pacman-ahriman*.conf) to new location /usr/share/devtools/pacman.conf.d/ under name ahriman.conf. After that make sure to remove any community mentions from configurations (e.g. /usr/share/devtools/pacman.conf.d/ahriman.conf, /etc/ahriman.ini) if there were any. The only thing which will change is devtools configuration.
Remove build chroot as it is incompatible, e.g. sudo ahriman service-clean --chroot.
Run sudo -u ahriman ahriman update --no-aur --no-local --no-manual -yy in order to update local databases.

To 2.12.0

This release includes paths migration. Unlike usual case, no automatic migration is performed because it might break user configuration. The following noticeable changes have been made:

Path to pre-built packages now includes repository name, i.e. it has been changed from /var/lib/ahriman/packages/x86_64 to /var/lib/ahriman/packages/aur-clone/x86_64.
Path to pacman databases now includes repository name too, it has been changed from /var/lib/ahriman/pacman/x86_64 to /var/lib/ahriman/pacman/aur-clone/x86_64.
Path to repository itself also includes repository name, from /var/lib/ahriman/repository/x86_64 to /var/lib/ahriman/repository/aur-clone/x86_64.

In order to migrate to the new filesystem tree the following actions are required:

Stop and disable all services, e.g. timer and web service:

sudo systemctl disable --now ahriman@x86_64.timer
sudo systemctl disable --now ahriman-web@x86_64

Create directory tree. It can be done by running ahriman service-tree-migrate subcommand. It performs copying between the old repository tree and the new one. Alternatively directories can be copied by hands.
Edit configuration in case if anything is pointing to the old path, e.g. HTML report generation, in the way in which it will point to the directory inside repository specific one, e.g. /var/lib/ahriman/repository/x86_64 to /var/lib/ahriman/repository/aur-clone/x86_64.
Run setup command (i.e. ahriman service-setup) again with the same arguments as used before. This step can be done manually by editing devtools pacman configuration (/usr/share/devtools/pacman.conf.d/ahriman-x86_64.conf by default) replacing Server with path to the repository, e.g.:
```
[aur-clone]
SigLevel = Optional TrustAll
Server = file:///var/lib/ahriman/repository/aur-clone/x86_64
```
In case of manual interventions make sure to remove architecture reference from web sections (if any) to avoid ambiguity.
Make sure to update remote synchronization services if any. Almost all of them rely on current repository tree by default, so it is required to setup either redirects or configure to synchronize to the old locations (e.g. object_path option for S3 synchronization).
Enable and start services again. Unit template parameter should include both repository architecture and name, dash separated, e.g. x86_64-aur-clone, where x86_64 is the repository architecture and aur-clone is the repository name:
```
sudo systemctl enable --now ahriman@x86_64-aur-clone.timer
sudo systemctl enable --now ahriman-web
```