readme: overview and environment

README.md

@@ -1,2 +1,34 @@
-# nextcloud13
+# NextCloud Backup using borgbackup
+
+This script automates backing up your NextCloud installation using borgbackup
+and a remote ssh-capable storage system.  I suggest using rsync.net since they
+have great speeds and a special pricing structure for borgbackup/attic users
+([details here](https://www.rsync.net/products/attic.html)).
+
+This script automates the following tasks:
+
+- Optionally copies a 503 error page to your webserver so users know when your
+  server is unavailable due to backups being performed. The 503 file is removed
+  when the backup is completed so users can login again
+- Dumps mySQL database and adds it to the backup
+- Handles entering and exiting NextCloud's maintenance mode to 'lock' accounts
+  so changes are not made during the backup process
+- Allows you to specify additional files you want backed up
+- Allows you to specify files/directories to exclude from your backups (e.g.
+  previews)
+- Runs 'borg prune' to make sure you are trimming old backups on your schedule
+- Creates an clear, easy to parse log file so you can easily keep an eye on your
+  backups and any errors/warnings
+
+## Environment notes
+
+The script is designed to be easy to use but still be flexible enough to
+accommodate a wide range of common NextCloud setups.  I have tested it with
+NextCloud 13 and 14 using a standard LEMP setup (Debian Stretch, NGINX, mariaDB
+& PHP7).  The script accepts several parameters to provide it with the settings
+it requires to function.  In addition, it reads external files for SQL and borg
+settings, so you don't have to weed through the script code to supply things
+like passwords.
+
+## Script parameters