backups/mastodon_db_backup.sh - modify to work with docker-compose

And on runko.social.coop.  Used as a stopgap backup solution there.

backups/mastodon_db_backup.sh

@@ -2,8 +2,8 @@
 
 # A script which backs up the mastodon database(s)
 
-container=mastodon_db
-backupdir=/var/vol2/postgres
+container=db
+backupdir=/opt/backups/postgres
 
 # This performs a cyclic dump to files with the container and date in the name
 # It also creates a link to a file containing the backup sequence number 0 or 1
@@ -21,7 +21,7 @@ backup() {
   rm -f $(readlink -f "$backupdir/$link")
 
   # create new backup file
-  docker exec -it "$cname" pg_dumpall -U postgres -c -v | gzip >"$backupdir/$file"
+  docker-compose -f /opt/social.coop/sauce/docker/docker-compose.yml exec "$cname" pg_dumpall -U postgres -c -v | gzip >"$backupdir/$file"
   status=$?
 
   # link the sequence number to it
@@ -30,7 +30,7 @@ backup() {
 }
 
 # Iterate over all matching container names
-for cname in $(docker container ls -f name=$container --format '{{.Names}}')
-do 
-  backup $cname
-done
+#for cname in $(docker container ls -f name=$container --format '{{.Names}}')
+#do 
+  backup $container
+#done