migration format 0.3

doc/migration-format.md

-# IndieHosters migration format, version 0.2.2
+# IndieHosters migration format
+
+## Version 0.2.2
 
 When a user exports their data for domain.com, they get a zip or tar file that contains different files, depending on which application is
 running on their domain:
 
-## If using the 'static' application
+### If using the 'static' application
 
 * TLS/domain.com.pem - Concatenation of the unencrypted private and public key of the TLS certificate, and intermediate CA cert if applicable.
 * static/www-content - static content to be placed in the web root
 
-## If using the 'static-git' application
+### If using the 'static-git' application
 
 * TLS/domain.com.pem - Concatenation of the unencrypted private and public key of the TLS certificate, and intermediate CA cert if applicable.
 * static-git/GITURL - git url to pull the static website content from
 
-## If using the 'WordPress' application
+### If using the 'WordPress' application
 
 * TLS/domain.com.pem - Concatenation of the unencrypted private and public key of the TLS certificate, and intermediate CA cert if applicable.
 * mysql/dump.sql - the dump of all their MySQL databases
@@ -23,7 +25,7 @@ running on their domain:
 * wordpress/.htaccess - htaccess file for WordPress
 * wordpress/wp-content - php files to be placed in the web root
 
-## If using the 'Known' application
+### If using the 'Known' application
 
 * TLS/domain.com.pem - Concatenation of the unencrypted private and public key of the TLS certificate, and intermediate CA cert if applicable.
 * mysql/dump.sql - the dump of all their MySQL databases
@@ -31,3 +33,28 @@ running on their domain:
 * known/ - php files to be placed in the web root
 * known/.env - contains the MySQL password
 * known/login.txt - email address and password for the Known admin panel
+
+
+# Version 0.3 (proposed, not implemented yet)
+
+### General
+
+An IndieHosters migration archive is a directory structure (probably packaged up as a tar file or zip file).
+There should be a 'runme.sh' file in the root of the archive.
+
+
+### Single-tennant usage
+
+When executing `./runme.sh` from the folder on an empty server that supports Docker, a single-tennant server should be started.
+
+
+### Multi-tennant postfix-forwarder support
+
+When executing it on a server that is already running an instance of indiehosters/postfix-forwarder:0.3 on port 25 of the host system,
+any email forwarding rules for this domain should be added to the existing postfix-forwarder instance.
+
+
+### Multi-tennant haproxy support
+
+When executing it on a server that is already running an instance of indiehosters/haproxy:0.3 on ports 80 and 443 of the host system,
+the web app (if any) should be added as a backend to the existing haproxy instance.