[installer]: configure kots to backup in-cluster mysql

Author: Simon Emms

install/installer/third_party/charts/mysql/values.yaml

@@ -8,6 +8,19 @@ mysql:
     # We switched to the specific version because "5.7" was broken at least once
     tag: 5.7.34-debian-10-r55
   primary:
+    # Backup settings
+    podAnnotations:
+      backup.velero.io/backup-volumes: backup
+      pre.hook.backup.velero.io/command: |
+        ["/bin/bash", "-c", "mysqldump -u root -p$MYSQL_ROOT_PASSWORD --databases $MYSQL_DATABASE gitpod-sessions -h 127.0.0.1 > /backup/mysqldump.sql"]
+      pre.hook.backup.velero.io/timeout: 5m
+    extraVolumes:
+      - name: backup
+        emptyDir: {}
+    extraVolumeMounts:
+      - name: backup
+        mountPath: /backup
+    # End of backup settings
     extraEnvVars:
       # We rely on this in our DB implementations: NULL (re-)sets configured columns to be initialized with CURRENT_TIMESTAMP.
       # OFF is the default as documented [here](https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_explicit_defaults_for_timestamp) (we also see this in GCP), but not for this chart.
@@ -19,4 +32,4 @@ mysql:
   serviceAccount:
     create: false
   volumePermissions:
-    enabled: true
+    enabled: true