Added support for backup to a remote server using rsync

* updated web interface to get data from user
* added way to list files from server

It’s not using the “username” field of the yaml configuration
file to minimise the amount of patches needed. So the username
is actually sorted within the rsync URL.

Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net>

management/backup.py

@@ -351,6 +351,33 @@ def list_target_files(config):
 	if p.scheme == "file":
 		return [(fn, os.path.getsize(os.path.join(p.path, fn))) for fn in os.listdir(p.path)]
 
+	elif p.scheme == "rsync":
+		env = load_environment()
+		rsync_fn_size_re = re.compile(r'.*    ([^ ]*) [^ ]* [^ ]* (.*)')
+		rsync_target = '{host}:{path}'
+
+		_, target_host, target_path = config['target'].split('//')
+		target_path = '/' + target_path
+
+		rsync_command = [ 'rsync',
+					'-e',
+					'/usr/bin/ssh -o StrictHostKeyChecking=no -oBatchMode=yes',
+					'--list-only',
+					'-r',
+					rsync_target.format(
+						host=target_host,
+						path=target_path)
+				]
+
+		code, listing = shell('check_output', rsync_command, get_env(env), trap=True)
+		if code == 0:
+			for l in listing.split('\n'):
+				match = rsync_fn_size_re.match(l)
+				if match:
+					yield (match.groups()[1], int(match.groups()[0].replace(',','')))
+		else:
+			raise ValueError("Connection to rsync host failed")
+
 	elif p.scheme == "s3":
 		# match to a Region
 		fix_boto() # must call prior to importing boto

management/templates/system-backup.html

@@ -16,16 +16,52 @@
       <select class="form-control" rows="1" id="backup-target-type" onchange="toggle_form()">
         <option value="off">Nowhere (Disable Backups)</option>
         <option value="local">{{hostname}}</option>
+        <option value="rsync">rsync</option>
         <option value="s3">Amazon S3</option>
       </select>
     </div>
   </div>
+  <!-- LOCAL BACKUP -->
   <div class="form-group backup-target-local">
     <div class="col-sm-10 col-sm-offset-2">
       <p>Backups are stored on this machine&rsquo;s own hard disk. You are responsible for periodically using SFTP (FTP over SSH) to copy the backup files from <tt id="backup-location"></tt> to a safe location. These files are encrypted, so they are safe to store anywhere.</p>
       <p>Separately copy the encryption password from <tt class="backup-encpassword-file"></tt> to a safe and secure location. You will need this file to decrypt backup files.</p>
     </div>
   </div>
+  <!-- RSYNC BACKUP -->
+  <div class="form-group backup-target-rsync">
+    <div class="col-sm-10 col-sm-offset-2">
+
+      <p>Backups synced to a remote machine using rsync over SSH, with local
+      copies in <tt id="backup-location"></tt>. These files are encrypted, so
+      they are safe to store anywhere.</p> <p>Separately copy the encryption
+      password from <tt class="backup-encpassword-file"></tt> to a safe and
+      secure location. You will need this file to decrypt backup files.</p>
+      <p>Separately copy the SSH public key from <tt>/root/.ssh/id_rsa.pub</tt>
+      and add it to your backup account on your remote server, in the
+      <tt>~/.ssh/authorized_keys</tt> file.</p>
+
+    </div>
+  </div>
+  <div class="form-group backup-target-rsync">
+    <label for="backup-target-rsync-host" class="col-sm-2 control-label">Hostname</label>
+    <div class="col-sm-8">
+      <input type="text" placeholder="hostname.local" class="form-control" rows="1" id="backup-target-rsync-host">
+    </div>
+  </div>
+  <div class="form-group backup-target-rsync">
+    <label for="backup-target-rsync-path" class="col-sm-2 control-label">Path</label>
+    <div class="col-sm-8">
+        <input type="text" placeholder="/backups/{{hostname}}" class="form-control" rows="1" id="backup-target-rsync-path">
+    </div>
+  </div>
+  <div class="form-group backup-target-rsync">
+    <label for="backup-target-user" class="col-sm-2 control-label">Username</label>
+    <div class="col-sm-8">
+      <input type="text" class="form-control" rows="1" id="backup-target-user">
+    </div>
+  </div>
+  <!-- S3 BACKUP -->
   <div class="form-group backup-target-s3">
     <div class="col-sm-10 col-sm-offset-2">
       <p>Backups are stored in an Amazon Web Services S3 bucket. You must have an AWS account already.</p>
@@ -92,7 +128,7 @@
 
 function toggle_form() {
   var target_type = $("#backup-target-type").val();
-  $(".backup-target-local, .backup-target-s3").hide();
+  $(".backup-target-local, .backup-target-rsync, .backup-target-s3").hide();
   $(".backup-target-" + target_type).show();
 }
 
@@ -160,16 +196,29 @@ function show_system_backup() {
 }
 
 function show_custom_backup() {
-    $(".backup-target-local, .backup-target-s3").hide();
+    $(".backup-target-local, .backup-target-rsync, .backup-target-s3").hide();
     api(
       "/system/backup/config",
       "GET",
       { },
       function(r) {
+        $("#backup-target-user").val(r.target_user);
+        $("#backup-target-pass").val(r.target_pass);
+        $("#min-age").val(r.min_age_in_days);
+        $('#backup-location').text(r.file_target_directory);
+        $('.backup-encpassword-file').text(r.enc_pw_file);
+
         if (r.target == "file://" + r.file_target_directory) {
           $("#backup-target-type").val("local");
         } else if (r.target == "off") {
           $("#backup-target-type").val("off");
+        } else if (r.target.substring(0, 5) == "rsync://") {
+          $("#backup-target-type").val("rsync");
+          var path = r.target.substring(8).split('//');
+          var [ user, host ] = path.shift().split('@');
+          $("#backup-target-rsync").val(user);
+          $("#backup-target-rsync-host").val(host);
+          $("#backup-target-rsync-path").val('/'+path);
         } else if (r.target.substring(0, 5) == "s3://") {
           $("#backup-target-type").val("s3");
           var hostpath = r.target.substring(5).split('/');
@@ -177,11 +226,6 @@ function show_custom_backup() {
           $("#backup-target-s3-host").val(host);
           $("#backup-target-s3-path").val(hostpath.join('/'));
         }
-        $("#backup-target-user").val(r.target_user);
-        $("#backup-target-pass").val(r.target_pass);
-        $("#min-age").val(r.min_age_in_days);
-        $('#backup-location').text(r.file_target_directory);
-        $('.backup-encpassword-file').text(r.enc_pw_file);
         toggle_form()
       })
 }
@@ -196,6 +240,12 @@ function set_custom_backup() {
     target = target_type;
   else if (target_type == "s3")
     target = "s3://" + $("#backup-target-s3-host").val() + "/" + $("#backup-target-s3-path").val();
+  else if (target_type == "rsync") {
+    target = "rsync://" + $("#backup-target-user").val() + "@" + $("#backup-target-rsync-host").val()
+                                                                + "/" + $("#backup-target-rsync-path").val();
+    target_user = '';
+  }
+
 
   var min_age = $("#min-age").val();
   api(