geo-rep: gsyncd: add --ignore-deletes option

When this option is set, a file deleted on master will not trigger
a delete operation on the slave. Hence, the slave will remain as a
superset of the master and can be used to recover the master in case
of crash and/or accidental deletes.

This options is not enabled by default.

Change-Id: I9244d9dfa4f38f19436036f36bec0d9c3a1f7993
BUG: 3552
Reviewed-on: http://review.gluster.com/426
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Csaba Henk <csaba@gluster.com>

3 files changed, 29 insertions, 3 deletions

diff --git a/xlators/features/marker/utils/syncdaemon/gsyncd.py b/xlators/features/marker/utils/syncdaemon/gsyncd.py
index 797000970a5..9cae4d407f4 100644
--- a/xlators/features/marker/utils/syncdaemon/gsyncd.py
+++ b/xlators/features/marker/utils/syncdaemon/gsyncd.py
@@ -148,6 +148,7 @@ def main_i():
     op.add_option('-p', '--pid-file',      metavar='PIDF',  type=str, action='callback', callback=store_abs)
     op.add_option('-l', '--log-file',      metavar='LOGF',  type=str, action='callback', callback=store_abs)
     op.add_option('--state-file',          metavar='STATF', type=str, action='callback', callback=store_abs)
+    op.add_option('--ignore-deletes',      default=False, action='store_true')
     op.add_option('-L', '--log-level',     metavar='LVL')
     op.add_option('-r', '--remote-gsyncd', metavar='CMD',   default=os.path.abspath(sys.argv[0]))
     op.add_option('--volume-id',           metavar='UUID')
@@ -188,7 +189,7 @@ def main_i():
     op.add_option('--canonicalize-url',        dest='url_print', action='callback', callback=store_local_curry('canon'))
     op.add_option('--canonicalize-escape-url', dest='url_print', action='callback', callback=store_local_curry('canon_esc'))
 
-    tunables = [ norm(o.get_opt_string()[2:]) for o in op.option_list if o.callback in (store_abs, None) and o.get_opt_string() not in ('--version', '--help') ]
+    tunables = [ norm(o.get_opt_string()[2:]) for o in op.option_list if o.callback in (store_abs, 'store_true', None) and o.get_opt_string() not in ('--version', '--help') ]
 
     # precedence for sources of values: 1) commandline, 2) cfg file, 3) defaults
     # -- for this to work out we need to tell apart defaults from explicitly set
diff --git a/xlators/features/marker/utils/syncdaemon/master.py b/xlators/features/marker/utils/syncdaemon/master.py
index de4b324214e..9e54dc4faf2 100644
--- a/xlators/features/marker/utils/syncdaemon/master.py
+++ b/xlators/features/marker/utils/syncdaemon/master.py
@@ -9,7 +9,7 @@ from errno import ENOENT, ENODATA
 from threading import currentThread, Condition, Lock
 
 from gconf import gconf
-from syncdutils import FreeObject, Thread, GsyncdError
+from syncdutils import FreeObject, Thread, GsyncdError, boolify
 
 URXTIME = (-1, 0)
 
@@ -346,7 +346,7 @@ class GMaster(object):
                 self.add_failjob(path, 'remote-entries-fail')
                 return
         dd = set(des) - set(dem)
-        if dd:
+        if dd and not boolify(gconf.ignore_deletes):
             self.slave.server.purge(path, dd)
         chld = []
         for e in dem:
diff --git a/xlators/features/marker/utils/syncdaemon/syncdutils.py b/xlators/features/marker/utils/syncdaemon/syncdutils.py
index f82f412a014..e3098d5f4ea 100644
--- a/xlators/features/marker/utils/syncdaemon/syncdutils.py
+++ b/xlators/features/marker/utils/syncdaemon/syncdutils.py
@@ -222,3 +222,28 @@ def getusername(uid = None):
     if uid == None:
         uid = os.geteuid()
     return pwd.getpwuid(uid).pw_name
+
+def boolify(s):
+    """
+    Generic string to boolean converter
+
+    return
+    - Quick return if string 's' is of type bool
+    - True if it's in true_list
+    - False if it's in false_list
+    - Warn if it's not present in either and return False
+    """
+    true_list  = ['true', 'yes', '1', 'on']
+    false_list = ['false', 'no', '0', 'off']
+
+    if isinstance(s, bool):
+        return s
+
+    rv = False
+    lstr = s.lower()
+    if lstr in true_list:
+        rv = True
+    elif not lstr in false_list:
+        logging.warn("Unknown string (%s) in string to boolean conversion defaulting to False\n" % (s))
+
+    return rv