The pre-migrate backup failed with "mysqldump exited 2" and nothing else.
Reproduced on the host with stderr captured:
ERROR 1045: Plugin caching_sha2_password could not be loaded:
/usr/lib/mariadb/plugin/caching_sha2_password.so: No such file or directory
Alpine's `mysql-client` is MariaDB's client and ships an EMPTY plugin
directory, so it cannot perform caching_sha2_password — MySQL 8.4's default and
effectively only auth method. `mariadb-connector-c` provides the plugin.
This was never about the deploy backup alone. Every mysqldump/mysql call from
the API container was broken, which means the whole Operaciones panel — backup,
restore, sync, re-import — could not work in a container. It went unnoticed
because that feature had only ever been run with the API on a developer
machine, where the Oracle client is installed. Verified after the fix: dump
exits 0, gzip valid, 31 CREATE TABLEs.
Also fixed, both found while chasing the above:
- The backup script reported an exit code and nothing else, because a detached
exec captures no output — which is precisely why this needed a manual
reproduction. mysqldump's stderr is now redirected to a file and read back
through a short attached exec on failure, so the deploy log states the cause.
Verified against live prod: the log now carries the 1045 line itself.
- Listing ONLY 100.100.100.100 as the containers' resolver costs them public
DNS, since MagicDNS does not forward upstream unless the tailnet defines
global nameservers. Nothing at runtime needed it, but `apk` inside the
container stopped resolving, and anything outbound would have too. A public
fallback resolver is now listed after MagicDNS.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>