partitionedfs: implement 'get_partuuid()' method

Implement a method for getting the partition UUID for a mapped partition.
We will use it for mounting by partition UUID a bit later.

Change-Id: Iaf497c34eaf84e8e25dd5019a99d76f3674744cd
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>

diff --git a/mic/utils/partitionedfs.py b/mic/utils/partitionedfs.py
index 2f4de2b..d63c0e7 100644 (file)
--- a/mic/utils/partitionedfs.py
+++ b/mic/utils/partitionedfs.py
@@ -42,12 +42,13 @@ class PartitionedMount(Mount):
         self.mapped = False
         self.mountOrder = []
         self.unmountOrder = []
-        self.parted=find_binary_path("parted")
-        self.kpartx=find_binary_path("kpartx")
-        self.mkswap=find_binary_path("mkswap")
+        self.parted = find_binary_path("parted")
+        self.kpartx = find_binary_path("kpartx")
+        self.mkswap = find_binary_path("mkswap")
+        self.blkid = find_binary_path("blkid")
         self.btrfscmd=None
-        self.mountcmd=find_binary_path("mount")
-        self.umountcmd=find_binary_path("umount")
+        self.mountcmd = find_binary_path("mount")
+        self.umountcmd = find_binary_path("umount")
         self.skipformat = skipformat
         self.snapshot_created = self.skipformat
         # Size of a sector used in calculations
@@ -413,6 +414,26 @@ class PartitionedMount(Mount):
 
             d['mapped'] = False
 
+    def get_partuuid(self, device):
+        """ Find UUID of a partition corresponding to a device node
+        'device'. """
+
+        args = [ self.blkid, '-c', '/dev/null', '-p', '-i', device ]
+        msger.debug("Running 'blkid': " + str(args))
+        rc, output = runner.runtool(args)
+        if rc != 0:
+            raise MountError("blkid failed: %s" % output)
+
+        # Parse blkid output and search for the PART_ENTRY_UUID value
+        partuuid = None
+        for line in output.splitlines():
+            var, value = line.partition("=")[::2]
+            if var.strip() == "PART_ENTRY_UUID":
+                partuuid = value.strip()
+
+        return partuuid
+
+
     def __calculate_mountorder(self):
         msger.debug("Calculating mount order")
         for p in self.partitions: