Backup the pgsql data after rsyncing them

During a migration to kubernetes the server is deployed after the rsync
to prepare the SSL secrets and PVC. This has the nasty effect to
corrupt the synchronized data with a too recent catalog version ID.
This would let the DB migration to fail starting the old postgresql
server.

To workaround this, move the data to the the backup place after the
rsync instead of the begining of the db upgrade.

mgradm/shared/templates/migrateScriptTemplate.go

@@ -87,8 +87,10 @@ echo "Extracting time zone..."
 $SSH {{ .SourceFqdn }} timedatectl show -p Timezone >/var/lib/uyuni-tools/data
 
 echo "Extracting postgresql versions..."
-echo "image_pg_version=$(rpm -qa --qf '%{VERSION}\n' 'name=postgresql[0-8][0-9]-server'  | cut -d. -f1 | sort -n | tail -1)" >> /var/lib/uyuni-tools/data
-echo "current_pg_version=$(cat /var/lib/pgsql/data/PG_VERSION)" >> /var/lib/uyuni-tools/data
+image_pg_version=$(rpm -qa --qf '%{VERSION}\n' 'name=postgresql[0-8][0-9]-server'  | cut -d. -f1 | sort -n | tail -1)
+current_pg_version=$(cat /var/lib/pgsql/data/PG_VERSION)
+echo "image_pg_version=$image_pg_version" >> /var/lib/uyuni-tools/data
+echo "current_pg_version=$current_pg_version" >> /var/lib/uyuni-tools/data
 
 grep '^db_user' /etc/rhn/rhn.conf | sed 's/[ \t]//g' >>/var/lib/uyuni-tools/data
 grep '^db_password' /etc/rhn/rhn.conf | sed 's/[ \t]//g' >>/var/lib/uyuni-tools/data
@@ -111,6 +113,15 @@ fi
 
 sed 's/address=[^:]*:/address=*:/' -i /etc/tomcat/conf.d/remote_debug.conf
 
+# Create a backup copy of the data to prepare DB upgrade.
+# We need to upgrade the deployment before upgrading the database to get the SSL certificates ready.
+# To avoid corrupting the database files, move them to where the upgrade script will expect them.
+echo "Posgresql versions: image: $image_pg_version, current: $current_pg_version"
+if test "$image_pg_version" != "$current_pg_version"; then
+    echo "Backing up the database files ..."
+	mv /var/lib/pgsql/data /var/lib/pgsql/data-pg$current_pg_version
+fi
+
 {{ if .Kubernetes }}
 echo 'server.no_ssl = 1' >> /etc/rhn/rhn.conf;
 echo "Extracting SSL certificate and authority"

mgradm/shared/templates/pgsqlVersionUpgradeScriptTemplate.go

@@ -22,8 +22,9 @@ test -d /usr/lib/postgresql$NEW_VERSION/bin
 echo "Testing presence of postgresql$OLD_VERSION..."
 test -d /usr/lib/postgresql$OLD_VERSION/bin
 
-echo "Create a backup at /var/lib/pgsql/data-pg$OLD_VERSION..."
-mv /var/lib/pgsql/data /var/lib/pgsql/data-pg$OLD_VERSION
+# Data have already been backed up at the end of the migration script
+# Reset the potentially created new pgsql data
+rm -rf /var/lib/pgsql/data
 echo "Create new database directory..."
 mkdir -p /var/lib/pgsql/data
 chown -R postgres:postgres /var/lib/pgsql
@@ -44,6 +45,8 @@ echo "Running initdb using postgres user"
 echo "Any suggested command from the console should be run using postgres user"
 su -s /bin/bash - postgres -c "initdb -D /var/lib/pgsql/data --locale=$POSTGRES_LANG"
 echo "Successfully initialized new postgresql $NEW_VERSION database."
+
+
 su -s /bin/bash - postgres -c "pg_upgrade --old-bindir=/usr/lib/postgresql$OLD_VERSION/bin --new-bindir=/usr/lib/postgresql$NEW_VERSION/bin --old-datadir=/var/lib/pgsql/data-pg$OLD_VERSION --new-datadir=/var/lib/pgsql/data $FAST_UPGRADE"
 
 cp /var/lib/pgsql/data-pg$OLD_VERSION/pg_hba.conf /var/lib/pgsql/data