geo-rep: Support for using Volinfo from Conf file

Once Geo-replication is started, it runs Gluster commands to get Volume
info from Master and Slave. With this patch, Georep can get Volume info
from Conf file if `--use-gconf-volinfo` argument is specified to monitor

Create a config(Or add to the config if exists) with following fields

    [vars]
    master-bricks=NODEID:HOSTNAME:PATH,..
    slave-bricks=NODEID:HOSTNAME,..
    master-volume-id=
    slave-volume-id=
    master-replica-count=
    master-disperse_count=

Note: Exising Geo-replication is not affected since this is activated
only when `--use-gconf-volinfo` is passed while spawning `gsyncd
monitor`

Tiering support is not yet added since Tiering + Glusterd2 is still
under discussion.

Fixes: #396
Change-Id: I281baccbad03686c00f6488a8511dd6db0edc57a
Signed-off-by: Aravinda VK <avishwan@redhat.com>

1 files changed, 18 insertions, 50 deletions

diff --git a/geo-replication/syncdaemon/monitor.py b/geo-replication/syncdaemon/monitor.py
index a193b57caff..257d34a743b 100644
--- a/geo-replication/syncdaemon/monitor.py
+++ b/geo-replication/syncdaemon/monitor.py
@@ -14,7 +14,6 @@ import time
 import signal
 import logging
 import xml.etree.ElementTree as XET
-from subprocess import PIPE
 from threading import Lock
 from errno import ECHILD, ESRCH
 import random
@@ -23,9 +22,9 @@ from resource import SSH
 import gsyncdconfig as gconf
 from rconf import rconf
 from syncdutils import select, waitpid, errno_wrap, lf, grabpidfile
-from syncdutils import set_term_handler, is_host_local, GsyncdError
-from syncdutils import Thread, finalize, Popen, Volinfo
-from syncdutils import gf_event, EVENT_GEOREP_FAULTY
+from syncdutils import set_term_handler, GsyncdError
+from syncdutils import Thread, finalize, Volinfo, VolinfoFromGconf
+from syncdutils import gf_event, EVENT_GEOREP_FAULTY, get_up_nodes
 from gsyncdstatus import GeorepStatus, set_monitor_status
 
 
@@ -54,43 +53,6 @@ def get_subvol_num(brick_idx, vol, hot):
         return str(cnt)
 
 
-def get_slave_bricks_status(host, vol):
-    po = Popen(['gluster', '--xml', '--remote-host=' + host,
-                'volume', 'status', vol, "detail"],
-               stdout=PIPE, stderr=PIPE)
-    vix = po.stdout.read()
-    po.wait()
-    po.terminate_geterr(fail_on_err=False)
-    if po.returncode != 0:
-        logging.info(lf("Volume status command failed, unable to get "
-                        "list of up nodes, returning empty list",
-                        volume=vol,
-                        error=po.returncode))
-        return []
-    vi = XET.fromstring(vix)
-    if vi.find('opRet').text != '0':
-        logging.info(lf("Unable to get list of up nodes, "
-                        "returning empty list",
-                        volume=vol,
-                        error=vi.find('opErrstr').text))
-        return []
-
-    up_hosts = set()
-
-    try:
-        for el in vi.findall('volStatus/volumes/volume/node'):
-            if el.find('status').text == '1':
-                up_hosts.add((el.find('hostname').text,
-                              el.find('peerid').text))
-    except (ParseError, AttributeError, ValueError) as e:
-        logging.info(lf("Parsing failed to get list of up nodes, "
-                        "returning empty list",
-                        volume=vol,
-                        error=e))
-
-    return list(up_hosts)
-
-
 class Monitor(object):
 
     """class which spawns and manages gsyncd workers"""
@@ -116,7 +78,7 @@ class Monitor(object):
         errno_wrap(os.kill, [-os.getpid(), signal.SIGTERM], [ESRCH])
 
     def monitor(self, w, argv, cpids, agents, slave_vol, slave_host, master,
-                suuid):
+                suuid, slavenodes):
         """the monitor loop
 
         Basic logic is a blantantly simple blunt heuristics:
@@ -180,8 +142,7 @@ class Monitor(object):
             # If the connected slave node is down then try to connect to
             # different up node.
             current_slave_host = remote_host
-            slave_up_hosts = get_slave_bricks_status(
-                slave_host, slave_vol)
+            slave_up_hosts = get_up_nodes(slavenodes, gconf.get("ssh-port"))
 
             if (current_slave_host, remote_id) not in slave_up_hosts:
                 if len(slave_up_hosts) > 0:
@@ -354,7 +315,7 @@ class Monitor(object):
         self.status[w[0]['dir']].set_worker_status(self.ST_INCON)
         return ret
 
-    def multiplex(self, wspx, suuid, slave_vol, slave_host, master):
+    def multiplex(self, wspx, suuid, slave_vol, slave_host, master, slavenodes):
         argv = [os.path.basename(sys.executable), sys.argv[0]]
 
         cpids = set()
@@ -363,7 +324,7 @@ class Monitor(object):
         for wx in wspx:
             def wmon(w):
                 cpid, _ = self.monitor(w, argv, cpids, agents, slave_vol,
-                                       slave_host, master, suuid)
+                                       slave_host, master, suuid, slavenodes)
                 time.sleep(1)
                 self.lock.acquire()
                 for cpid in cpids:
@@ -380,7 +341,10 @@ class Monitor(object):
 
 
 def distribute(master, slave):
-    mvol = Volinfo(master.volume, master.host)
+    if rconf.args.use_gconf_volinfo:
+        mvol = VolinfoFromGconf(master.volume, master=True)
+    else:
+        mvol = Volinfo(master.volume, master.host)
     logging.debug('master bricks: ' + repr(mvol.bricks))
     prelude = []
     slave_host = None
@@ -393,7 +357,11 @@ def distribute(master, slave):
 
     logging.debug('slave SSH gateway: ' + slave.remote_addr)
 
-    svol = Volinfo(slave.volume, "localhost", prelude)
+    if rconf.args.use_gconf_volinfo:
+        svol = VolinfoFromGconf(slave.volume, master=False)
+    else:
+        svol = Volinfo(slave.volume, "localhost", prelude)
+
     sbricks = svol.bricks
     suuid = svol.uuid
     slave_host = slave.remote_addr.split('@')[-1]
@@ -415,14 +383,14 @@ def distribute(master, slave):
 
     workerspex = []
     for idx, brick in enumerate(mvol.bricks):
-        if is_host_local(brick['uuid']):
+        if rconf.args.local_node_id == brick['uuid']:
             is_hot = mvol.is_hot(":".join([brick['host'], brick['dir']]))
             workerspex.append((brick,
                                slaves[idx % len(slaves)],
                                get_subvol_num(idx, mvol, is_hot),
                                is_hot))
     logging.debug('worker specs: ' + repr(workerspex))
-    return workerspex, suuid, slave_vol, slave_host, master
+    return workerspex, suuid, slave_vol, slave_host, master, slavenodes
 
 
 def monitor(local, remote):