[unpackfs] Add settings per-item for exclude and excludeFile

- support excluding specific files / lists when rsyncing, in case
   the squashfs has more in it than you really want to copy over.

src/modules/unpackfs/main.py

@@ -49,7 +49,7 @@ class UnpackEntry:
     :param sourcefs:
     :param destination:
     """
-    __slots__ = ['source', 'sourcefs', 'destination', 'copied', 'total']
+    __slots__ = ['source', 'sourcefs', 'destination', 'copied', 'total', 'exclude', 'excludeFile']
 
     def __init__(self, source, sourcefs, destination):
         """
@@ -66,6 +66,8 @@ class UnpackEntry:
         self.source = source
         self.sourcefs = sourcefs
         self.destination = destination
+        self.exclude = None
+        self.excludeFile = None
         self.copied = 0
         self.total = 0
 
@@ -399,6 +401,12 @@ def run():
                 utils.debug(".. assuming that the previous targets will create that directory.")
 
         unpack.append(UnpackEntry(source, sourcefs, destination))
+        # Optional settings
+        if entry.get("exclude", None):
+            unpack[-1].exclude = entry["exclude"]
+        if entry.get("excludeFile", None):
+            unpack[-1].excludeFile = entry["excludeFile"]
+
         is_first = False
 
     unpackop = UnpackOperation(unpack)

src/modules/unpackfs/unpackfs.conf

@@ -23,6 +23,13 @@
 #       empty string, which effectively is / (the root) of the target
 #       system.
 #
+# Each list item **optionally** can include the following attributes:
+#   - *exclude* is a list of values that is expanded into --exclude
+#       arguments for rsync (each entry in exclude gets its own --exclude).
+#   - *excludeFile* is a single file that is passed to rsync as an
+#       --exclude-file argument. This should be a full pathname
+#       inside the **host** filesystem.
+#
 # EXAMPLES
 #
 # Usually you list a filesystem image to unpack; you can use
@@ -75,3 +82,7 @@ unpack:
     -   source: ../CHANGES
         sourcefs: file
         destination: "/tmp/changes.txt"
+    -   source: src/qml/calamares/slideshow/
+        sourcefs: file
+        destination: "/tmp/"
+        exclude: [ "*.qmlc", "qmldir" ]