Yolo postgresql 11 -> 13 cluster migration

locales/en.json

@@ -427,6 +427,7 @@
     "migration_description_0019_extend_permissions_features": "Extend/rework the app permission management system",
     "migration_description_0020_ssh_sftp_permissions": "Add SSH and SFTP permissions support",
     "migration_description_0022_php73_to_php74_pools": "Migrate php7.3-fpm 'pool' conf files to php7.4",
+    "migration_description_0023_postgresql_11_to_13": "Migrate databases from PostgreSQL 11 to 13",
     "migration_ldap_backup_before_migration": "Creating a backup of LDAP database and apps settings prior to the actual migration.",
     "migration_ldap_can_not_backup_before_migration": "The backup of the system could not be completed before the migration failed. Error: {error:s}",
     "migration_ldap_migration_failed_trying_to_rollback": "Could not migrate... trying to roll back the system.",
@@ -453,6 +454,9 @@
     "migration_0018_failed_to_reset_legacy_rules": "Failed to reset legacy iptables rules: {error}",
     "migration_0019_add_new_attributes_in_ldap": "Add new attributes for permissions in LDAP database",
     "migration_0019_slapd_config_will_be_overwritten": "It looks like you manually edited the slapd configuration. For this critical migration, YunoHost needs to force the update of the slapd configuration. The original files will be backuped in {conf_backup_folder}.",
+    "migration_0023_postgresql_11_not_installed": "PostgreSQL was not installed on your system. Nothing to do.",
+    "migration_0023_postgresql_13_not_installed": "PostgreSQL 11 is installed, but not postgresql 13!? Something weird might have happened on your system :(...",
+    "migration_0023_not_enough_space": "Make sufficient space available in {path} to run the migration.",
     "migrations_already_ran": "Those migrations are already done: {ids}",
     "migrations_cant_reach_migration_file": "Could not access migrations files at the path '%s'",
     "migrations_dependencies_not_satisfied": "Run these migrations: '{dependencies_id}', before migration {id}.",

src/yunohost/data_migrations/0023_postgresql_11_to_13.py

@@ -0,0 +1,82 @@
+import subprocess
+
+from moulinette import m18n
+from yunohost.utils.error import YunohostError, YunohostValidationError
+from moulinette.utils.log import getActionLogger
+
+from yunohost.tools import Migration
+from yunohost.utils.filesystem import free_space_in_directory, space_used_by_directory
+
+logger = getActionLogger("yunohost.migration")
+
+
+class MyMigration(Migration):
+
+    "Migrate DBs from Postgresql 11 to 13 after migrating to Bullseye"
+
+    dependencies = ["migrate_to_bullseye"]
+
+    def run(self):
+
+        if not self.package_is_installed("postgresql-11"):
+            logger.warning(m18n.n("migration_0023_postgresql_11_not_installed"))
+            return
+
+        if not self.package_is_installed("postgresql-13"):
+            raise YunohostValidationError("migration_0023_postgresql_13_not_installed")
+
+        # Make sure there's a 11 cluster
+        try:
+            self.runcmd("pg_lsclusters | grep -q '^11 '")
+        except Exception:
+            logger.warning(
+                "It looks like there's not active 11 cluster, so probably don't need to run this migration"
+            )
+            return
+
+        if not space_used_by_directory(
+            "/var/lib/postgresql/11"
+        ) > free_space_in_directory("/var/lib/postgresql"):
+            raise YunohostValidationError(
+                "migration_0023_not_enough_space", path="/var/lib/postgresql/"
+            )
+
+        self.runcmd("systemctl stop postgresql")
+        self.runcmd(
+            "LC_ALL=C pg_dropcluster --stop 13 main || true"
+        )  # We do not trigger an exception if the command fails because that probably means cluster 13 doesn't exists, which is fine because it's created during the pg_upgradecluster)
+        self.runcmd("LC_ALL=C pg_upgradecluster -m upgrade 11 main")
+        self.runcmd("LC_ALL=C pg_dropcluster --stop 11 main")
+        self.runcmd("systemctl start postgresql")
+
+    def package_is_installed(self, package_name):
+
+        (returncode, out, err) = self.runcmd(
+            "dpkg --list | grep '^ii ' | grep -q -w {}".format(package_name),
+            raise_on_errors=False,
+        )
+        return returncode == 0
+
+    def runcmd(self, cmd, raise_on_errors=True):
+
+        logger.debug("Running command: " + cmd)
+
+        p = subprocess.Popen(
+            cmd,
+            shell=True,
+            executable="/bin/bash",
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+        )
+
+        out, err = p.communicate()
+        returncode = p.returncode
+        if raise_on_errors and returncode != 0:
+            raise YunohostError(
+                "Failed to run command '{}'.\nreturncode: {}\nstdout:\n{}\nstderr:\n{}\n".format(
+                    cmd, returncode, out, err
+                )
+            )
+
+        out = out.strip().split("\n")
+        return (returncode, out, err)