eventsapi: Gluster Eventing Feature implementation

[Depends on http://review.gluster.org/14627]

Design is available in `glusterfs-specs`, A change from the design
is support of webhook instead of Websockets as discussed in the design

http://review.gluster.org/13115

Since Websocket support depends on REST APIs, I will add Websocket support
once REST APIs patch gets merged

Usage:
Run following command to start/stop Eventsapi server in all Peers,
which will collect the notifications from any Gluster daemon and emits
to configured client.

    gluster-eventsapi start|stop|restart|reload

Status of running services can be checked using,

    gluster-eventsapi status

Events listener is a HTTP(S) server which listens to events emited by
the Gluster. Create a HTTP Server to listen on POST and register that
URL using,

    gluster-eventsapi webhook-add <URL> [--bearer-token <TOKEN>]

For example, if HTTP Server running in `http://192.168.122.188:9000`
then add that URL using,

    gluster-eventsapi webhook-add http://192.168.122.188:9000

If it expects a Token then specify it using `--bearer-token` or `-t`

We can also test Webhook if all peer nodes can send message or not
using,

    gluster-eventsapi webhook-test <URL> [--bearer-token <TOKEN>]

Configurations can be viewed/updated using,

    gluster-eventsapi config-get [--name]
    gluster-eventsapi config-set <NAME> <VALUE>
    gluster-eventsapi config-reset <NAME|all>

If any one peer node was down during config-set/reset or webhook
modifications, Run sync command from good node when a peer node comes
back. Automatic update is not yet implemented.

    gluster-eventsapi sync

Basic Events Client(HTTP Server) is included with the code, Start
running the client with required port and start listening to the
events.

    /usr/share/glusterfs/scripts/eventsdash.py --port 8080

Default port is 9000, if no port is specified, once it started running
then configure gluster-eventsapi to send events to that client.

Eventsapi Client can be outside of the Cluster, it can be run event on
Windows. But only requirement is the client URL should be accessible
by all peer nodes.(Or ngrok(https://ngrok.com) like tools can be used)

Events implemented with this patch,
- Volume Create
- Volume Start
- Volume Stop
- Volume Delete
- Peer Attach
- Peer Detach

It is easy to add/support more events, since it touches Gluster cmd
code and to avoid merge conflicts I will add support for more events
once this patch merges.

BUG: 1334044
Change-Id: I316827ac9dd1443454df7deffe4f54835f7f6a08
Signed-off-by: Aravinda VK <avishwan@redhat.com>
Reviewed-on: http://review.gluster.org/14248
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>

13 files changed, 1059 insertions, 0 deletions

diff --git a/events/Makefile.am b/events/Makefile.am
new file mode 100644
index 00000000000..04a74efc228
--- /dev/null
+++ b/events/Makefile.am
@@ -0,0 +1,6 @@
+SUBDIRS = src tools
+
+noinst_PYTHON = eventskeygen.py
+
+install-data-hook:
+	$(INSTALL) -d -m 755 $(DESTDIR)@GLUSTERD_WORKDIR@/events
diff --git a/events/eventskeygen.py b/events/eventskeygen.py
new file mode 100644
index 00000000000..656a7dce9f1
--- /dev/null
+++ b/events/eventskeygen.py
@@ -0,0 +1,65 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+#  Copyright (c) 2016 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
+
+GLUSTER_SRC_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+eventtypes_h = os.path.join(GLUSTER_SRC_ROOT, "libglusterfs/src/eventtypes.h")
+eventtypes_py = os.path.join(GLUSTER_SRC_ROOT, "events/src/eventtypes.py")
+
+# When adding new keys add it to the END
+keys = (
+    "EVENT_PEER_ATTACH",
+    "EVENT_PEER_DETACH",
+
+    "EVENT_VOLUME_CREATE",
+    "EVENT_VOLUME_START",
+    "EVENT_VOLUME_STOP",
+    "EVENT_VOLUME_DELETE",
+)
+
+LAST_EVENT = "EVENT_LAST"
+
+ERRORS = (
+    "EVENT_SEND_OK",
+    "EVENT_ERROR_INVALID_INPUTS",
+    "EVENT_ERROR_SOCKET",
+    "EVENT_ERROR_CONNECT",
+    "EVENT_ERROR_SEND"
+)
+
+# Generate eventtypes.h
+with open(eventtypes_h, "w") as f:
+    f.write("#ifndef __EVENTTYPES_H__\n")
+    f.write("#define __EVENTTYPES_H__\n\n")
+    f.write("typedef enum {\n")
+    for k in ERRORS:
+        f.write("    {0},\n".format(k))
+    f.write("} event_errors_t;\n")
+
+    f.write("\n")
+
+    f.write("typedef enum {\n")
+    for k in keys:
+        f.write("    {0},\n".format(k))
+
+    f.write("    {0}\n".format(LAST_EVENT))
+    f.write("} eventtypes_t;\n")
+    f.write("\n#endif /* __EVENTTYPES_H__ */\n")
+
+# Generate eventtypes.py
+with open(eventtypes_py, "w") as f:
+    f.write("# -*- coding: utf-8 -*-\n")
+    f.write("all_events = [\n")
+    for ev in keys:
+        f.write('    "{0}",\n'.format(ev))
+    f.write("]\n")
diff --git a/events/src/Makefile.am b/events/src/Makefile.am
new file mode 100644
index 00000000000..528f0208fe2
--- /dev/null
+++ b/events/src/Makefile.am
@@ -0,0 +1,24 @@
+EXTRA_DIST = glustereventsd.py __init__.py  eventsapiconf.py.in eventtypes.py \
+	handlers.py utils.py peer_eventsapi.py eventsconfig.json
+
+eventsdir = $(libexecdir)/glusterfs/events
+eventspeerscriptdir = $(libexecdir)/glusterfs
+eventsconfdir = $(sysconfdir)/glusterfs
+eventsconf_DATA = eventsconfig.json
+
+events_PYTHON = __init__.py eventsapiconf.py eventtypes.py handlers.py utils.py
+events_SCRIPTS = glustereventsd.py
+eventspeerscript_SCRIPTS = peer_eventsapi.py
+
+install-exec-hook:
+	$(mkdir_p) $(DESTDIR)$(sbindir)
+	rm -f $(DESTDIR)$(sbindir)/glustereventsd
+	ln -s $(libexecdir)/glusterfs/events/glustereventsd.py \
+		$(DESTDIR)$(sbindir)/glustereventsd
+	rm -f $(DESTDIR)$(sbindir)/gluster-eventing
+	ln -s $(libexecdir)/glusterfs/peer_eventsapi.py \
+		$(DESTDIR)$(sbindir)/gluster-eventsapi
+
+uninstall-hook:
+	rm -f $(DESTDIR)$(sbindir)/glustereventsd
+	rm -f $(DESTDIR)$(sbindir)/gluster-eventsapi
diff --git a/events/src/__init__.py b/events/src/__init__.py
new file mode 100644
index 00000000000..f27c53a4df4
--- /dev/null
+++ b/events/src/__init__.py
@@ -0,0 +1,10 @@
+# -*- coding: utf-8 -*-
+#
+#  Copyright (c) 2016 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.
+#
diff --git a/events/src/eventsapiconf.py.in b/events/src/eventsapiconf.py.in
new file mode 100644
index 00000000000..702e1d21820
--- /dev/null
+++ b/events/src/eventsapiconf.py.in
@@ -0,0 +1,22 @@
+# -*- coding: utf-8 -*-
+#
+#  Copyright (c) 2016 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.
+#
+
+SERVER_ADDRESS = "@localstatedir@/run/gluster/events.sock"
+DEFAULT_CONFIG_FILE = "@SYSCONF_DIR@/glusterfs/eventsconfig.json"
+CUSTOM_CONFIG_FILE_TO_SYNC = "/events/config.json"
+CUSTOM_CONFIG_FILE = "@GLUSTERD_WORKDIR@" + CUSTOM_CONFIG_FILE_TO_SYNC
+WEBHOOKS_FILE_TO_SYNC = "/events/webhooks.json"
+WEBHOOKS_FILE = "@GLUSTERD_WORKDIR@" + WEBHOOKS_FILE_TO_SYNC
+LOG_FILE = "@localstatedir@/log/glusterfs/events.log"
+EVENTSD = "glustereventsd"
+CONFIG_KEYS = ["log_level"]
+BOOL_CONFIGS = []
+RESTART_CONFIGS = []
diff --git a/events/src/eventsconfig.json b/events/src/eventsconfig.json
new file mode 100644
index 00000000000..ce2c775f0bd
--- /dev/null
+++ b/events/src/eventsconfig.json
@@ -0,0 +1,3 @@
+{
+    "log_level": "INFO"
+}
diff --git a/events/src/eventtypes.py b/events/src/eventtypes.py
new file mode 100644
index 00000000000..4812e659de3
--- /dev/null
+++ b/events/src/eventtypes.py
@@ -0,0 +1,9 @@
+# -*- coding: utf-8 -*-
+all_events = [
+    "EVENT_PEER_ATTACH",
+    "EVENT_PEER_DETACH",
+    "EVENT_VOLUME_CREATE",
+    "EVENT_VOLUME_START",
+    "EVENT_VOLUME_STOP",
+    "EVENT_VOLUME_DELETE",
+]
diff --git a/events/src/glustereventsd.py b/events/src/glustereventsd.py
new file mode 100644
index 00000000000..3fa57686a8b
--- /dev/null
+++ b/events/src/glustereventsd.py
@@ -0,0 +1,151 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+#  Copyright (c) 2016 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.
+#
+
+from __future__ import print_function
+import asyncore
+import socket
+import os
+from multiprocessing import Process, Queue
+import sys
+import signal
+
+from eventtypes import all_events
+import handlers
+import utils
+from eventsapiconf import SERVER_ADDRESS
+from utils import logger
+
+# Global Queue, EventsHandler will add items to the queue
+# and process_event will gets each item and handles it
+events_queue = Queue()
+events_server_pid = None
+
+
+def process_event():
+    """
+    Seperate process which handles all the incoming events from Gluster
+    processes.
+    """
+    while True:
+        data = events_queue.get()
+        logger.debug("EVENT: {0}".format(repr(data)))
+        try:
+            # Event Format <TIMESTAMP> <TYPE> <DETAIL>
+            ts, key, value = data.split(" ", 2)
+        except ValueError:
+            logger.warn("Invalid Event Format {0}".format(data))
+            continue
+
+        data_dict = {}
+        try:
+            # Format key=value;key=value
+            data_dict = dict(x.split('=') for x in value.split(';'))
+        except ValueError:
+            logger.warn("Unable to parse Event {0}".format(data))
+            continue
+
+        try:
+            # Event Type to Function Map, Recieved event data will be in
+            # the form <TIMESTAMP> <TYPE> <DETAIL>, Get Event name for the
+            # recieved Type/Key and construct a function name starting with
+            # handle_ For example: handle_event_volume_create
+            func_name = "handle_" + all_events[int(key)].lower()
+        except IndexError:
+            # This type of Event is not handled?
+            logger.warn("Unhandled Event: {0}".format(key))
+            func_name = None
+
+        if func_name is not None:
+            # Get function from handlers module
+            func = getattr(handlers, func_name, None)
+            # If func is None, then handler unimplemented for that event.
+            if func is not None:
+                func(ts, int(key), data_dict)
+            else:
+                # Generic handler, broadcast whatever received
+                handlers.generic_handler(ts, int(key), data_dict)
+
+
+def process_event_wrapper():
+    try:
+        process_event()
+    except KeyboardInterrupt:
+        return
+
+
+class GlusterEventsHandler(asyncore.dispatcher_with_send):
+
+    def handle_read(self):
+        data = self.recv(8192)
+        if data:
+            events_queue.put(data)
+            self.send(data)
+
+
+class GlusterEventsServer(asyncore.dispatcher):
+
+    def __init__(self):
+        global events_server_pid
+        asyncore.dispatcher.__init__(self)
+        # Start the Events listener process which listens to
+        # the global queue
+        p = Process(target=process_event_wrapper)
+        p.start()
+        events_server_pid = p.pid
+
+        # Create UNIX Domain Socket, bind to path
+        self.create_socket(socket.AF_UNIX, socket.SOCK_STREAM)
+        self.bind(SERVER_ADDRESS)
+        self.listen(5)
+
+    def handle_accept(self):
+        pair = self.accept()
+        if pair is not None:
+            sock, addr = pair
+            GlusterEventsHandler(sock)
+
+
+def signal_handler_sigusr2(sig, frame):
+    if events_server_pid is not None:
+        os.kill(events_server_pid, signal.SIGUSR2)
+    utils.load_all()
+
+
+def init_event_server():
+    utils.setup_logger()
+
+    # Delete Socket file if Exists
+    try:
+        os.unlink(SERVER_ADDRESS)
+    except OSError:
+        if os.path.exists(SERVER_ADDRESS):
+            print ("Failed to cleanup socket file {0}".format(SERVER_ADDRESS),
+                   file=sys.stderr)
+            sys.exit(1)
+
+    utils.load_all()
+
+    # Start the Eventing Server, UNIX DOMAIN SOCKET Server
+    GlusterEventsServer()
+    asyncore.loop()
+
+
+def main():
+    try:
+        init_event_server()
+    except KeyboardInterrupt:
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    signal.signal(signal.SIGUSR2, signal_handler_sigusr2)
+    main()
diff --git a/events/src/handlers.py b/events/src/handlers.py
new file mode 100644
index 00000000000..9b756a91d51
--- /dev/null
+++ b/events/src/handlers.py
@@ -0,0 +1,21 @@
+# -*- coding: utf-8 -*-
+#
+#  Copyright (c) 2016 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 utils
+
+
+def generic_handler(ts, key, data):
+    """
+    Generic handler to broadcast message to all peers, custom handlers
+    can be created by func name handler_<event_name>
+    Ex: handle_event_volume_create(ts, key, data)
+    """
+    utils.publish(ts, key, data)
diff --git a/events/src/peer_eventsapi.py b/events/src/peer_eventsapi.py
new file mode 100644
index 00000000000..7887d77351c
--- /dev/null
+++ b/events/src/peer_eventsapi.py
@@ -0,0 +1,521 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+#  Copyright (c) 2016 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.
+#
+
+from __future__ import print_function
+import os
+import json
+from errno import EEXIST
+
+import requests
+import fasteners
+from prettytable import PrettyTable
+
+from gluster.cliutils import (Cmd, execute, node_output_ok, node_output_notok,
+                              sync_file_to_peers, GlusterCmdException,
+                              output_error, execute_in_peers, runcli)
+
+from events.eventsapiconf import (WEBHOOKS_FILE_TO_SYNC,
+                                  WEBHOOKS_FILE,
+                                  DEFAULT_CONFIG_FILE,
+                                  CUSTOM_CONFIG_FILE,
+                                  CUSTOM_CONFIG_FILE_TO_SYNC,
+                                  EVENTSD,
+                                  CONFIG_KEYS,
+                                  BOOL_CONFIGS,
+                                  RESTART_CONFIGS)
+
+
+def file_content_overwrite(fname, data):
+    with open(fname + ".tmp", "w") as f:
+        f.write(json.dumps(data))
+
+    os.rename(fname + ".tmp", fname)
+
+
+def create_custom_config_file_if_not_exists():
+    mkdirp(os.path.dirname(CUSTOM_CONFIG_FILE))
+    if not os.path.exists(CUSTOM_CONFIG_FILE):
+        with open(CUSTOM_CONFIG_FILE, "w") as f:
+            f.write("{}")
+
+
+def create_webhooks_file_if_not_exists():
+    mkdirp(os.path.dirname(WEBHOOKS_FILE))
+    if not os.path.exists(WEBHOOKS_FILE):
+        with open(WEBHOOKS_FILE, "w") as f:
+            f.write("{}")
+
+
+def boolify(value):
+    val = False
+    if value.lower() in ["enabled", "true", "on", "yes"]:
+        val = True
+    return val
+
+
+def mkdirp(path, exit_on_err=False, logger=None):
+    """
+    Try creating required directory structure
+    ignore EEXIST and raise exception for rest of the errors.
+    Print error in stderr and exit
+    """
+    try:
+        os.makedirs(path)
+    except (OSError, IOError) as e:
+        if e.errno == EEXIST and os.path.isdir(path):
+            pass
+        else:
+            output_error("Fail to create dir %s: %s" % (path, e))
+
+
+def is_enabled(service):
+    rc, out, err = execute(["systemctl", "is-enabled", service])
+    return rc == 0
+
+
+def is_active(service):
+    rc, out, err = execute(["systemctl", "is-active", service])
+    return rc == 0
+
+
+def enable_service(service):
+    if not is_enabled(service):
+        cmd = ["systemctl", "enable", service]
+        return execute(cmd)
+
+    return (0, "", "")
+
+
+def disable_service(service):
+    if is_enabled(service):
+        cmd = ["systemctl", "disable", service]
+        return execute(cmd)
+
+    return (0, "", "")
+
+
+def start_service(service):
+    rc, out, err = enable_service(service)
+    if rc != 0:
+        return (rc, out, err)
+
+    cmd = ["systemctl", "start", service]
+    return execute(cmd)
+
+
+def stop_service(service):
+    rc, out, err = disable_service(service)
+    if rc != 0:
+        return (rc, out, err)
+
+    cmd = ["systemctl", "stop", service]
+    return execute(cmd)
+
+
+def restart_service(service):
+    rc, out, err = stop_service(service)
+    if rc != 0:
+        return (rc, out, err)
+
+    return start_service(service)
+
+
+def reload_service(service):
+    if is_active(service):
+        cmd = ["systemctl", "reload", service]
+        return execute(cmd)
+
+    return (0, "", "")
+
+
+def sync_to_peers(restart=False):
+    if os.path.exists(WEBHOOKS_FILE):
+        try:
+            sync_file_to_peers(WEBHOOKS_FILE_TO_SYNC)
+        except GlusterCmdException as e:
+            output_error("Failed to sync Webhooks file: [Error: {0}]"
+                         "{1}".format(e[0], e[2]))
+
+    if os.path.exists(CUSTOM_CONFIG_FILE):
+        try:
+            sync_file_to_peers(CUSTOM_CONFIG_FILE_TO_SYNC)
+        except GlusterCmdException as e:
+            output_error("Failed to sync Config file: [Error: {0}]"
+                         "{1}".format(e[0], e[2]))
+
+    action = "node-reload"
+    if restart:
+        action = "node-restart"
+
+    out = execute_in_peers(action)
+    table = PrettyTable(["NODE", "NODE STATUS", "SYNC STATUS"])
+    table.align["NODE STATUS"] = "r"
+    table.align["SYNC STATUS"] = "r"
+
+    for p in out:
+        table.add_row([p.hostname,
+                       "UP" if p.node_up else "DOWN",
+                       "OK" if p.ok else "NOT OK: {0}".format(
+                           p.error)])
+
+    print (table)
+
+
+def node_output_handle(resp):
+    rc, out, err = resp
+    if rc == 0:
+        node_output_ok(out)
+    else:
+        node_output_notok(err)
+
+
+def action_handle(action):
+    out = execute_in_peers("node-" + action)
+    column_name = action.upper()
+    if action == "status":
+        column_name = EVENTSD.upper()
+
+    table = PrettyTable(["NODE", "NODE STATUS", column_name + " STATUS"])
+    table.align["NODE STATUS"] = "r"
+    table.align[column_name + " STATUS"] = "r"
+
+    for p in out:
+        status_col_val = "OK" if p.ok else "NOT OK: {0}".format(
+            p.error)
+        if action == "status":
+            status_col_val = "DOWN"
+            if p.ok:
+                status_col_val = p.output
+
+        table.add_row([p.hostname,
+                       "UP" if p.node_up else "DOWN",
+                       status_col_val])
+
+    print (table)
+
+
+class NodeStart(Cmd):
+    name = "node-start"
+
+    def run(self, args):
+        node_output_handle(start_service(EVENTSD))
+
+
+class StartCmd(Cmd):
+    name = "start"
+
+    def run(self, args):
+        action_handle("start")
+
+
+class NodeStop(Cmd):
+    name = "node-stop"
+
+    def run(self, args):
+        node_output_handle(stop_service(EVENTSD))
+
+
+class StopCmd(Cmd):
+    name = "stop"
+
+    def run(self, args):
+        action_handle("stop")
+
+
+class NodeRestart(Cmd):
+    name = "node-restart"
+
+    def run(self, args):
+        node_output_handle(restart_service(EVENTSD))
+
+
+class RestartCmd(Cmd):
+    name = "restart"
+
+    def run(self, args):
+        action_handle("restart")
+
+
+class NodeReload(Cmd):
+    name = "node-reload"
+
+    def run(self, args):
+        node_output_handle(reload_service(EVENTSD))
+
+
+class ReloadCmd(Cmd):
+    name = "reload"
+
+    def run(self, args):
+        action_handle("reload")
+
+
+class NodeStatus(Cmd):
+    name = "node-status"
+
+    def run(self, args):
+        node_output_ok("UP" if is_active(EVENTSD) else "DOWN")
+
+
+class StatusCmd(Cmd):
+    name = "status"
+
+    def run(self, args):
+        webhooks = {}
+        if os.path.exists(WEBHOOKS_FILE):
+            webhooks = json.load(open(WEBHOOKS_FILE))
+
+        print ("Webhooks: " + ("" if webhooks else "None"))
+        for w in webhooks:
+            print (w)
+
+        print ()
+        action_handle("status")
+
+
+class WebhookAddCmd(Cmd):
+    name = "webhook-add"
+
+    def args(self, parser):
+        parser.add_argument("url", help="URL of Webhook")
+        parser.add_argument("--bearer_token", "-t", help="Bearer Token",
+                            default="")
+
+    def run(self, args):
+        create_webhooks_file_if_not_exists()
+
+        with fasteners.InterProcessLock(WEBHOOKS_FILE):
+            data = json.load(open(WEBHOOKS_FILE))
+            if data.get(args.url, None) is not None:
+                output_error("Webhook already exists")
+
+            data[args.url] = args.bearer_token
+            file_content_overwrite(WEBHOOKS_FILE, data)
+
+        sync_to_peers()
+
+
+class WebhookModCmd(Cmd):
+    name = "webhook-mod"
+
+    def args(self, parser):
+        parser.add_argument("url", help="URL of Webhook")
+        parser.add_argument("--bearer_token", "-t", help="Bearer Token",
+                            default="")
+
+    def run(self, args):
+        create_webhooks_file_if_not_exists()
+
+        with fasteners.InterProcessLock(WEBHOOKS_FILE):
+            data = json.load(open(WEBHOOKS_FILE))
+            if data.get(args.url, None) is None:
+                output_error("Webhook does not exists")
+
+            data[args.url] = args.bearer_token
+            file_content_overwrite(WEBHOOKS_FILE, data)
+
+        sync_to_peers()
+
+
+class WebhookDelCmd(Cmd):
+    name = "webhook-del"
+
+    def args(self, parser):
+        parser.add_argument("url", help="URL of Webhook")
+
+    def run(self, args):
+        create_webhooks_file_if_not_exists()
+
+        with fasteners.InterProcessLock(WEBHOOKS_FILE):
+            data = json.load(open(WEBHOOKS_FILE))
+            if data.get(args.url, None) is None:
+                output_error("Webhook does not exists")
+
+            del data[args.url]
+            file_content_overwrite(WEBHOOKS_FILE, data)
+
+        sync_to_peers()
+
+
+class NodeWebhookTestCmd(Cmd):
+    name = "node-webhook-test"
+
+    def args(self, parser):
+        parser.add_argument("url")
+        parser.add_argument("bearer_token")
+
+    def run(self, args):
+        http_headers = {}
+        if args.bearer_token != ".":
+            http_headers["Authorization"] = "Bearer " + args.bearer_token
+
+        try:
+            resp = requests.post(args.url, headers=http_headers)
+        except requests.ConnectionError as e:
+            node_output_notok("{0}".format(e))
+
+        if resp.status_code != 200:
+            node_output_notok("{0}".format(resp.status_code))
+
+        node_output_ok()
+
+
+class WebhookTestCmd(Cmd):
+    name = "webhook-test"
+
+    def args(self, parser):
+        parser.add_argument("url", help="URL of Webhook")
+        parser.add_argument("--bearer_token", "-t", help="Bearer Token")
+
+    def run(self, args):
+        url = args.url
+        bearer_token = args.bearer_token
+        if not args.url:
+            url = "."
+        if not args.bearer_token:
+            bearer_token = "."
+
+        out = execute_in_peers("node-webhook-test", [url, bearer_token])
+
+        table = PrettyTable(["NODE", "NODE STATUS", "WEBHOOK STATUS"])
+        table.align["NODE STATUS"] = "r"
+        table.align["WEBHOOK STATUS"] = "r"
+
+        for p in out:
+            table.add_row([p.hostname,
+                           "UP" if p.node_up else "DOWN",
+                           "OK" if p.ok else "NOT OK: {0}".format(
+                               p.error)])
+
+        print (table)
+
+
+class ConfigGetCmd(Cmd):
+    name = "config-get"
+
+    def args(self, parser):
+        parser.add_argument("--name", help="Config Name")
+
+    def run(self, args):
+        data = json.load(open(DEFAULT_CONFIG_FILE))
+        if os.path.exists(CUSTOM_CONFIG_FILE):
+            data.update(json.load(open(CUSTOM_CONFIG_FILE)))
+
+        if args.name is not None and args.name not in CONFIG_KEYS:
+            output_error("Invalid Config item")
+
+        table = PrettyTable(["NAME", "VALUE"])
+        if args.name is None:
+            for k, v in data.items():
+                table.add_row([k, v])
+        else:
+            table.add_row([args.name, data[args.name]])
+
+        print (table)
+
+
+def read_file_content_json(fname):
+    content = "{}"
+    with open(fname) as f:
+        content = f.read()
+        if content.strip() == "":
+            content = "{}"
+
+    return json.loads(content)
+
+
+class ConfigSetCmd(Cmd):
+    name = "config-set"
+
+    def args(self, parser):
+        parser.add_argument("name", help="Config Name")
+        parser.add_argument("value", help="Config Value")
+
+    def run(self, args):
+        if args.name not in CONFIG_KEYS:
+            output_error("Invalid Config item")
+
+        with fasteners.InterProcessLock(CUSTOM_CONFIG_FILE):
+            data = json.load(open(DEFAULT_CONFIG_FILE))
+            if os.path.exists(CUSTOM_CONFIG_FILE):
+                config_json = read_file_content_json(CUSTOM_CONFIG_FILE)
+                data.update(config_json)
+
+            # Do Nothing if same as previous value
+            if data[args.name] == args.value:
+                return
+
+            # TODO: Validate Value
+            create_custom_config_file_if_not_exists()
+            new_data = read_file_content_json(CUSTOM_CONFIG_FILE)
+
+            v = args.value
+            if args.name in BOOL_CONFIGS:
+                v = boolify(args.value)
+
+            new_data[args.name] = v
+            file_content_overwrite(CUSTOM_CONFIG_FILE, new_data)
+
+            # If any value changed which requires restart of REST server
+            restart = False
+            if args.name in RESTART_CONFIGS:
+                restart = True
+
+            sync_to_peers(restart=restart)
+
+
+class ConfigResetCmd(Cmd):
+    name = "config-reset"
+
+    def args(self, parser):
+        parser.add_argument("name", help="Config Name or all")
+
+    def run(self, args):
+        with fasteners.InterProcessLock(CUSTOM_CONFIG_FILE):
+            changed_keys = []
+            data = {}
+            if os.path.exists(CUSTOM_CONFIG_FILE):
+                data = read_file_content_json(CUSTOM_CONFIG_FILE)
+
+            if not data:
+                return
+
+            if args.name.lower() == "all":
+                for k, v in data.items():
+                    changed_keys.append(k)
+
+                # Reset all keys
+                file_content_overwrite(CUSTOM_CONFIG_FILE, {})
+            else:
+                changed_keys.append(args.name)
+                del data[args.name]
+                file_content_overwrite(CUSTOM_CONFIG_FILE, data)
+
+            # If any value changed which requires restart of REST server
+            restart = False
+            for key in changed_keys:
+                if key in RESTART_CONFIGS:
+                    restart = True
+                    break
+
+            sync_to_peers(restart=restart)
+
+
+class SyncCmd(Cmd):
+    name = "sync"
+
+    def run(self, args):
+        sync_to_peers()
+
+
+if __name__ == "__main__":
+    runcli()
diff --git a/events/src/utils.py b/events/src/utils.py
new file mode 100644
index 00000000000..772221a1e25
--- /dev/null
+++ b/events/src/utils.py
@@ -0,0 +1,150 @@
+# -*- coding: utf-8 -*-
+#
+#  Copyright (c) 2016 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 json
+import os
+import logging
+
+import requests
+from eventsapiconf import (LOG_FILE,
+                           WEBHOOKS_FILE,
+                           DEFAULT_CONFIG_FILE,
+                           CUSTOM_CONFIG_FILE)
+import eventtypes
+
+from gluster.cliutils import get_node_uuid
+
+
+# Webhooks list
+_webhooks = {}
+# Default Log Level
+_log_level = "INFO"
+# Config Object
+_config = {}
+
+# Init Logger instance
+logger = logging.getLogger(__name__)
+
+
+def get_event_type_name(idx):
+    """
+    Returns Event Type text from the index. For example, VOLUME_CREATE
+    """
+    return eventtypes.all_events[idx].replace("EVENT_", "")
+
+
+def setup_logger():
+    """
+    Logging initialization, Log level by default will be INFO, once config
+    file is read, respective log_level will be set.
+    """
+    global logger
+    logger.setLevel(logging.INFO)
+
+    # create the logging file handler
+    fh = logging.FileHandler(LOG_FILE)
+
+    formatter = logging.Formatter("[%(asctime)s] %(levelname)s "
+                                  "[%(module)s - %(lineno)s:%(funcName)s] "
+                                  "- %(message)s")
+
+    fh.setFormatter(formatter)
+
+    # add handler to logger object
+    logger.addHandler(fh)
+
+
+def load_config():
+    """
+    Load/Reload the config from REST Config files. This function will
+    be triggered during init and when SIGUSR2.
+    """
+    global _config
+    _config = {}
+    if os.path.exists(DEFAULT_CONFIG_FILE):
+        _config = json.load(open(DEFAULT_CONFIG_FILE))
+    if os.path.exists(CUSTOM_CONFIG_FILE):
+        _config.update(json.load(open(CUSTOM_CONFIG_FILE)))
+
+
+def load_log_level():
+    """
+    Reads log_level from Config file and sets accordingly. This function will
+    be triggered during init and when SIGUSR2.
+    """
+    global logger, _log_level
+    new_log_level = _config.get("log_level", "INFO")
+    if _log_level != new_log_level:
+        logger.setLevel(getattr(logging, new_log_level.upper()))
+        _log_level = new_log_level.upper()
+
+
+def load_webhooks():
+    """
+    Load/Reload the webhooks list. This function will
+    be triggered during init and when SIGUSR2.
+    """
+    global _webhooks
+    _webhooks = {}
+    if os.path.exists(WEBHOOKS_FILE):
+        _webhooks = json.load(open(WEBHOOKS_FILE))
+
+
+def load_all():
+    """
+    Wrapper function to call all load/reload functions. This function will
+    be triggered during init and when SIGUSR2.
+    """
+    load_config()
+    load_webhooks()
+    load_log_level()
+
+
+def publish(ts, event_key, data):
+    message = {
+        "nodeid": get_node_uuid(),
+        "ts": int(ts),
+        "event": get_event_type_name(event_key),
+        "message": data
+    }
+    if _webhooks:
+        plugin_webhook(message)
+    else:
+        # TODO: Default action?
+        pass
+
+
+def plugin_webhook(message):
+    message_json = json.dumps(message, sort_keys=True)
+    logger.debug("EVENT: {0}".format(message_json))
+    for url, token in _webhooks.items():
+        http_headers = {"Content-Type": "application/json"}
+        if token != "" and token is not None:
+            http_headers["Authorization"] = "Bearer " + token
+
+        try:
+            resp = requests.post(url, headers=http_headers, data=message_json)
+        except requests.ConnectionError as e:
+            logger.warn("Event push failed to URL: {url}, "
+                        "Event: {event}, "
+                        "Status: {error}".format(
+                            url=url,
+                            event=message_json,
+                            error=e))
+            continue
+
+        if resp.status_code != 200:
+            logger.warn("Event push failed to URL: {url}, "
+                        "Event: {event}, "
+                        "Status Code: {status_code}".format(
+                            url=url,
+                            event=message_json,
+                            status_code=resp.status_code))
diff --git a/events/tools/Makefile.am b/events/tools/Makefile.am
new file mode 100644
index 00000000000..7d5e331e4e1
--- /dev/null
+++ b/events/tools/Makefile.am
@@ -0,0 +1,3 @@
+scriptsdir = $(datadir)/glusterfs/scripts
+scripts_SCRIPTS = eventsdash.py
+EXTRA_DIST = eventsdash.py
diff --git a/events/tools/eventsdash.py b/events/tools/eventsdash.py
new file mode 100644
index 00000000000..47fc56dda6e
--- /dev/null
+++ b/events/tools/eventsdash.py
@@ -0,0 +1,74 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+#  Copyright (c) 2016 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.
+#
+
+from argparse import ArgumentParser, RawDescriptionHelpFormatter
+import logging
+from datetime import datetime
+
+from flask import Flask, request
+
+app = Flask(__name__)
+app.logger.disabled = True
+log = logging.getLogger('werkzeug')
+log.disabled = True
+
+
+def human_time(ts):
+    return datetime.fromtimestamp(float(ts)).strftime("%Y-%m-%d %H:%M:%S")
+
+
+@app.route("/")
+def home():
+    return "OK"
+
+
+@app.route("/listen", methods=["POST"])
+def listen():
+    data = request.json
+    if data is None:
+        return "OK"
+
+    message = []
+    for k, v in data.get("message", {}).items():
+        message.append("{0}={1}".format(k, v))
+
+    print ("{0:20s} {1:20s} {2:36} {3}".format(
+        human_time(data.get("ts")),
+        data.get("event"),
+        data.get("nodeid"),
+        " ".join(message)))
+
+    return "OK"
+
+
+def main():
+    parser = ArgumentParser(formatter_class=RawDescriptionHelpFormatter,
+                            description=__doc__)
+    parser.add_argument("--port", type=int, help="Port", default=9000)
+    parser.add_argument("--debug", help="Run Server in debug mode",
+                        action="store_true")
+    args = parser.parse_args()
+
+    print ("{0:20s} {1:20s} {2:36} {3}".format(
+        "TIMESTAMP", "EVENT", "NODE ID", "MESSAGE"
+    ))
+    print ("{0:20s} {1:20s} {2:36} {3}".format(
+        "-"*20, "-"*20, "-"*36, "-"*20
+    ))
+    if args.debug:
+        app.debug = True
+
+    app.run(host="0.0.0.0", port=args.port)
+
+
+if __name__ == "__main__":
+    main()