Adding upstream version 2:4.20.0+dfsg.upstream/2%4.20.0+dfsg

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 213 insertions, 0 deletions

diff --git a/ctdb/utils/etcd/ctdb_etcd_lock b/ctdb/utils/etcd/ctdb_etcd_lock
new file mode 100755
index 0000000..dac2436
--- /dev/null
+++ b/ctdb/utils/etcd/ctdb_etcd_lock
@@ -0,0 +1,213 @@
+#!/usr/bin/env python3
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License as published by
+#    the Free Software Foundation, either version 3 of the License, or
+#    (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+#    Copyright (C) 2016 Jose A. Rivera <jarrpa@samba.org>
+#    Copyright (C) 2016 Ira Cooper <ira@samba.org>
+"""CTDB mutex helper using etcd.
+
+This script is intended to be run as a mutex helper for CTDB. It will try to
+connect to an existing etcd cluster and grab an etcd.Lock() to function as
+CTDB's cluster lock. Please see ctdb/doc/cluster_mutex_helper.txt for
+details on what we're SUPPOSED to be doing. :) To use this, include
+the following line in the ctdb.conf:
+
+    cluster lock = !/path/to/script
+
+You can also pass "-v", "-vv", or "-vvv" to include verbose output in the
+CTDB log. Additional "v"s indicate increases in verbosity.
+
+This mutex helper expects the system Python interpreter to have access to the
+etcd Python module. It also expects an etcd cluster to be configured and
+running. To integrate with this, there is an optional config file of the
+following format:
+
+key = value
+
+The following configuration variables (and their defaults) are defined for
+use by this script:
+
+port      = 2379   # connecting port for the etcd cluster
+lock_ttl  = 9      # seconds for TTL
+refresh   = 2      # seconds between attempts to maintain lock
+locks_dir = _ctdb  # where to store CTDB locks in etcd
+                   # The final etcd directory for any given lock looks like:
+                   #   /_locks/{locks_dir}/{netbios name}/
+
+In addition, any keyword parameter that can be used to configure an etcd
+client may be specified and modified here. For more documentation on these
+parameters, see here: https://github.com/jplana/python-etcd/
+
+"""
+import signal
+import time
+import sys
+import os
+import argparse
+import logging
+import subprocess
+
+import etcd
+
+# Helper Functions ------------------------------------------------------------
+#
+
+
+def process_args():
+    '''Process command-line arguments and return them.
+    '''
+    parser = argparse.ArgumentParser(
+        description=__doc__,
+        epilog='',
+        formatter_class=argparse.RawDescriptionHelpFormatter)
+    parser.add_argument('-v', '--verbose',
+                        action='count',
+                        help='Display verbose output to stderr. '
+                             'Default is no output.',
+                        default=0,
+                        )
+    parser.add_argument('-c', '--config',
+                        action='store',
+                        help='Configuration file to use. The default behavior '
+                             'is to look is the base CTDB configuration '
+                             'directory, which can be overwritten by setting '
+                             'the CTDB_BASE environment variable, for a file '
+                             'called \'etcd\'.  Default value is %(default)s.',
+                        default=os.path.join(os.getenv('CTDB_BASE',
+                                                       '/usr/local/etc/ctdb'),
+                                             'etcd'),
+                        )
+    args = parser.parse_args()
+
+    return args
+
+
+def setup_logging(verbose):
+    '''Setup logging based on specified verbosity.
+    '''
+
+    log_levels = [logging.ERROR, logging.WARNING, logging.DEBUG]
+    logging.basicConfig(level=log_levels[min(verbose, len(log_levels)-1)])
+
+
+def sigterm_handler(signum, frame):
+    """Handler for SIGTERM signals.
+    """
+    sys.exit()
+
+
+def print_nonl(out):
+    """Dumb shortcut for printing to stdout with no newline.
+    """
+    sys.stdout.write(str(out))
+    sys.stdout.flush()
+
+
+def int_or_not(s):
+    """Try to convert input to an integer.
+    """
+    try:
+        return int(s)
+    except ValueError:
+        return s
+
+# Mainline --------------------------------------------------------------------
+#
+
+
+def main():
+    args = process_args()
+
+    setup_logging(args.verbose)
+
+    # etcd config defaults
+    etcd_config = {
+        'port': 2379,
+        'locks_dir': '_ctdb',
+        'lock_ttl': 9,
+        'lock_refresh': 2,
+    }
+    # Find and read etcd config file
+    etcd_client_params = (
+        'host',
+        'port',
+        'srv_domain',
+        'version_prefix',
+        'read_timeout',
+        'allow_redirect',
+        'protocol',
+        'cert',
+        'ca_cert',
+        'username',
+        'password',
+        'allow_reconnect',
+        'use_proxies',
+        'expected_cluster_id',
+        'per_host_pool_size',
+    )
+    if os.path.isfile(args.config):
+        f = open(args.config, 'r')
+        for line in f:
+            (key, value) = line.split("=", 1)
+            etcd_config[key.strip()] = int_or_not(value.strip())
+
+    # Minor hack: call out to shell to retrieve CTDB netbios name and PNN.
+    tmp = subprocess.Popen("testparm -s --parameter-name 'netbios name'; \
+                          ctdb pnn",
+                           shell=True,
+                           universal_newlines=True,
+                           stdout=subprocess.PIPE
+                           ).stdout.read().strip()
+    nb_name, pnn = tmp.split()
+
+    # Try to get and hold the lock
+    try:
+        client = etcd.Client(
+            **{k: etcd_config[k] for k in
+               set(etcd_client_params).intersection(etcd_config)})
+        lock = etcd.Lock(client, etcd_config['locks_dir'] + "/" + nb_name)
+        lock._uuid = lock._uuid + "_" + pnn
+        logging.debug("Updated lock UUID: %s", lock.uuid)
+        ppid = os.getppid()
+        while True:
+            lock.acquire(blocking=False, lock_ttl=etcd_config['lock_ttl'])
+            if lock.is_acquired:
+                print_nonl(0)
+            else:
+                locks = "No locks found."
+                if logging.getLogger().getEffectiveLevel() == logging.DEBUG:
+                    keys = client.read(lock.path, recursive=True)
+                    if keys is not None:
+                        locks = "Existing locks:\n  "
+                        locks += '\n  '.join(
+                            (child.key + ": " + child.value for child in
+                             keys.children))
+                logging.debug("Lock contention. %s", locks)
+                print_nonl(1)
+                break
+            os.kill(ppid, 0)
+            time.sleep(etcd_config['lock_refresh'])
+    except (OSError, SystemExit):
+        if lock is not None and lock.is_acquired:
+            lock.release()
+    except Exception:
+        print_nonl(3)
+        if logging.getLogger().getEffectiveLevel() == logging.DEBUG:
+            raise
+
+
+if __name__ == "__main__":
+    signal.signal(signal.SIGTERM, sigterm_handler)
+
+    main()