https://macmule.com/2015/05/25/using-imagr-with-the-casper-suite/

simple_imagr_config.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>password</key>
    <string>b109f3bbbc244eb82441917ed06d618b9008dd09b3befd1b5e07394c706a8bb980b1d7785e5976ec049b46df5f1326af5a2ea6d103fd07c95385ffab0cacbc86</string>
    <key>workflows</key>
    <array>
    <dict>
        <key>name</key>
        <string>10.10.3 Restore</string>
        <key>restart_action</key>
        <string>none</string>
        <key>bless_target</key>
        <true/>
        <key>description</key>
        <string>10.10.3 AutoDMG OS.dmg</string>
        <key>components</key>
        <array>
            <dict>
                <key>type</key>
                <string>image</string>
                <key>first_boot</key>
                <false/>
                <key>url</key>
                <string>http://10.0.1.30/Packages/osx-10.10.3-14D136.hfs.dmg</string>
            </dict>
        </array>
    </dict>
    </array>
</dict>
</plist>