[linux-lvm] [PATCH 3/2] fs snapshot plugin: add ability to create snapshots during post transaction

[Mike Snitzer <msnitzer@fedoraproject.org>]

It can be useful to create a post transaction snapshot to allow tools
(e.g. snapper) to analyze the differences introduced by the yum
transaction.

Add 'create_snapshots_in_post' to main section of fs-snapshot.conf.

Signed-off-by: Mike Snitzer <msnitzer@fedoraproject.org>
---
 docs/yum-fs-snapshot.conf.5          |  4 ++++
 plugins/fs-snapshot/fs-snapshot.conf |  1 +
 plugins/fs-snapshot/fs-snapshot.py   | 10 +++++++++-
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/docs/yum-fs-snapshot.conf.5 b/docs/yum-fs-snapshot.conf.5
index dc5c0c1..4ac623a 100644
--- a/docs/yum-fs-snapshot.conf.5
+++ b/docs/yum-fs-snapshot.conf.5
@@ -20,6 +20,10 @@ utilizes configuration options in the form of
 .IP exclude
 This is a space delimited list of the mount points you do not wish to have
 snapshotted by this plugin.
+.SH OPTION
+.IP create_snapshots_in_post
+This is a boolean value used to control whether snapshots are also created
+after running the yum transaction.
 .SH OPTION - [lvm] section
 .IP enabled
 This is a boolean value used to control whether LVM snapshots will be
diff --git a/plugins/fs-snapshot/fs-snapshot.conf b/plugins/fs-snapshot/fs-snapshot.conf
index 3a67c69..9ada717 100644
--- a/plugins/fs-snapshot/fs-snapshot.conf
+++ b/plugins/fs-snapshot/fs-snapshot.conf
@@ -1,5 +1,6 @@
 [main]
 enabled = 1
+create_snapshots_in_post = 0
 
 [lvm]
 enabled = 0
diff --git a/plugins/fs-snapshot/fs-snapshot.py b/plugins/fs-snapshot/fs-snapshot.py
index 7483c2d..32a1f17 100644
--- a/plugins/fs-snapshot/fs-snapshot.py
+++ b/plugins/fs-snapshot/fs-snapshot.py
@@ -287,7 +287,7 @@ def _create_lvm_snapshot(conduit, snapshot_tag, volume):
         return 1
     return 2
 
-def pretrans_hook(conduit):
+def create_snapshots(conduit):
     """
     This runs before the transaction starts.  Try to snapshot anything and
     everything that is snapshottable, since we do not know what an RPM will
@@ -304,3 +304,11 @@ def pretrans_hook(conduit):
         elif rc == 2 and hasattr(conduit, 'registerPackageName'):
             # A snapshot was successfully created
             conduit.registerPackageName("yum-plugin-fs-snapshot")
+
+def pretrans_hook(conduit):
+    create_snapshots(conduit)
+
+def posttrans_hook(conduit):
+    create_snapshots_in_post = conduit.confBool('main', 'create_snapshots_in_post', default=0)
+    if create_snapshots_in_post:
+        create_snapshots(conduit)
-- 
1.8.1