feature/glusterfind: A tool to find incremental changes

Documentation is available in patch:
http://review.gluster.org/#/c/9800/

A tool which helps to get list of modified files or list of all files in
GlusterFS Volume using Changelog or find command.

Usage
=====
glusterfind --help

Create:
-------
glusterfind create --help

The tool creates status file $GLUSTERD_WORKDIR/SESSION/VOLUME/status
and records current timestamp to initiate the session. This timestamp
will be used as start time for next runs.

As part of create also generates ssh key and distributes to all peers.
and enables build.pgfid and changelog using volume set command.

Pre:
----
glusterfind pre --help

This command is used to generate the list of files modified after session
creation time or after last run. To get list of all files/dirs in Volume,
run pre command with `--full` argument.

The tool gets all nodes details using gluster volume info and runs node
agent for each brick in respective nodes via ssh command. Once these node
agents generate the output file, tool copies to local using scp. Merges all
the output files to generate the final output file.

Post:
-----
glusterfind post --help

After consuming the list, this sub command is called to update the session
time based on pre command status file.

List:
-----
glusterfind list --help

To view all the sessions

Delete:
-------
glusterfind delete --help

Delete session.

Known Issues
------------
1. Deleted files will not get listed, since we can't convert GFID to
   Path if file/dir is deleted.
2. Only new name will get listed if Renamed.
3. All hardlinks will get listed.

Change-Id: I82991feb0aea85cb6ec035fddbf80a2b276e86b0
BUG: 1193893
Signed-off-by: Aravinda VK <avishwan@redhat.com>
Reviewed-on: http://review.gluster.org/9682
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Venky Shankar <vshankar@redhat.com>
Reviewed-by: Prashanth Pai <ppai@redhat.com>
Reviewed-by: Kotresh HR <khiremat@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 83 insertions, 0 deletions

diff --git a/tools/glusterfind/src/libgfchangelog.py b/tools/glusterfind/src/libgfchangelog.py
new file mode 100644
index 00000000000..e54a16a4742
--- /dev/null
+++ b/tools/glusterfind/src/libgfchangelog.py
@@ -0,0 +1,83 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2015 Red Hat, Inc. <http://www.redhat.com/>
+# This file is part of GlusterFS.
+#
+# This file is licensed to you under your choice of the GNU Lesser
+# General Public License, version 3 or any later version (LGPLv3 or
+# later), or the GNU General Public License, version 2 (GPLv2), in all
+# cases as published by the Free Software Foundation.
+
+import os
+from ctypes import CDLL, get_errno, create_string_buffer, c_ulong, byref
+from ctypes import RTLD_GLOBAL
+from ctypes.util import find_library
+
+
+class ChangelogException(OSError):
+    pass
+
+
+libgfc = CDLL(find_library("gfchangelog"), use_errno=True, mode=RTLD_GLOBAL)
+
+
+def raise_oserr():
+    errn = get_errno()
+    raise ChangelogException(errn, os.strerror(errn))
+
+
+def cl_register(brick, path, log_file, log_level, retries=0):
+    ret = libgfc.gf_changelog_register(brick, path, log_file,
+                                       log_level, retries)
+    if ret == -1:
+        raise_oserr()
+
+
+def cl_history_scan():
+    ret = libgfc.gf_history_changelog_scan()
+    if ret == -1:
+        raise_oserr()
+
+    return ret
+
+
+def cl_history_changelog(changelog_path, start, end, num_parallel):
+    actual_end = c_ulong()
+    ret = libgfc.gf_history_changelog(changelog_path, start, end,
+                                      num_parallel,
+                                      byref(actual_end))
+    if ret == -1:
+        raise_oserr()
+
+    return actual_end.value
+
+
+def cl_history_startfresh():
+    ret = libgfc.gf_history_changelog_start_fresh()
+    if ret == -1:
+        raise_oserr()
+
+
+def cl_history_getchanges():
+    """ remove hardcoding for path name length """
+    def clsort(f):
+        return f.split('.')[-1]
+
+    changes = []
+    buf = create_string_buffer('\0', 4096)
+
+    while True:
+        ret = libgfc.gf_history_changelog_next_change(buf, 4096)
+        if ret in (0, -1):
+            break
+        changes.append(buf.raw[:ret - 1])
+    if ret == -1:
+        raise_oserr()
+
+    return sorted(changes, key=clsort)
+
+
+def cl_history_done(clfile):
+    ret = libgfc.gf_history_changelog_done(clfile)
+    if ret == -1:
+        raise_oserr()