added iocage migration doc

docs/chapters/migration.rst

@@ -0,0 +1,36 @@
+Stop the running jail and export it:
+
+.. code-block:: shell
+
+     iocage stop jailname
+     iocage export jailname
+
+Move the backup files (.zip and .sha256) into Bastille backup dir (default: /usr/local/bastille/backups/):
+
+.. code-block:: shell
+
+     mv /iocage/images/jailname_2020-03-26.* /usr/local/bastille/backups/
+
+for remote systems you could use rsync:
+
+.. code-block:: shell
+
+     rsync -avh /iocage/images/jailname_2020-03-26.* root@10.0.1.10:/usr/local/bastille/backups/
+
+     
+Import the iocage backup file (use zip file name)
+
+.. code-block:: shell
+
+     bastille import jailname_2020-03-26.zip
+
+Set your new ip address and interface:
+
+.. code-block:: shell
+
+     vim /usr/local/bastille/jails/jailname/jail.conf
+     interface = bastille0;
+     ip4.addr = "192.168.0.1";
+
+
+You can use you primary network interface instead of the virtual bastille0 interface as well if you know what you’re doing.

docs/index.rst

@@ -21,6 +21,7 @@ https://docs.bastillebsd.org.
    chapters/jail-config
    chapters/zfs-support
    chapters/gcp
+   chapters/migration
 
    copyright