From 7c9155257d37e2f9fc189a621bc8a808e296ab03 Mon Sep 17 00:00:00 2001
From: Ahmed Muawia Khan <amuawiakhan@gmail.com>
Date: Fri, 20 Jul 2018 13:07:43 +0200
Subject: [PATCH] Problem: BigchainDB main/parent process does not handle
 signals

---
 bigchaindb/tendermint/commands.py | 37 ++++++++++++++++++++++++++-----
 1 file changed, 32 insertions(+), 5 deletions(-)

diff --git a/bigchaindb/tendermint/commands.py b/bigchaindb/tendermint/commands.py
index d50f0f31..63b27235 100644
--- a/bigchaindb/tendermint/commands.py
+++ b/bigchaindb/tendermint/commands.py
@@ -1,8 +1,11 @@
+import bigchaindb
+
+import gevent
 import logging
 
 import setproctitle
+import signal
 
-import bigchaindb
 from bigchaindb.tendermint.lib import BigchainDB
 from bigchaindb.tendermint.core import App
 from bigchaindb.web import server, websocket_server
@@ -31,17 +34,27 @@ BANNER = """
 ****************************************************************************
 """
 
+PROCESSES = []
+
+
+def sig_handler(server):
+    logger.info('Shutting down BigchainDB. Goodbye!')
+    server.stop()
+    for p in PROCESSES:
+        p.terminate()
+
 
 def start():
     # Exchange object for event stream api
+    logger.info('Starting BigchainDB')
     exchange = Exchange()
-
     # start the web api
     app_server = server.create_server(
         settings=bigchaindb.config['server'],
         log_config=bigchaindb.config['log'],
         bigchaindb_factory=BigchainDB)
-    p_webapi = Process(name='bigchaindb_webapi', target=app_server.run)
+    p_webapi = Process(name='bigchaindb_webapi', target=app_server.run, daemon=True)
+    PROCESSES.append(p_webapi)
     p_webapi.start()
 
     # start message
@@ -50,16 +63,21 @@ def start():
     # start websocket server
     p_websocket_server = Process(name='bigchaindb_ws',
                                  target=websocket_server.start,
+                                 daemon=True,
                                  args=(exchange.get_subscriber_queue(EventTypes.BLOCK_VALID),))
+    PROCESSES.append(p_websocket_server)
     p_websocket_server.start()
 
     # connect to tendermint event stream
     p_websocket_client = Process(name='bigchaindb_ws_to_tendermint',
                                  target=event_stream.start,
+                                 daemon=True,
                                  args=(exchange.get_publisher_queue(),))
+    PROCESSES.append(p_websocket_client)
     p_websocket_client.start()
 
-    p_exchange = Process(name='bigchaindb_exchange', target=exchange.run)
+    p_exchange = Process(name='bigchaindb_exchange', target=exchange.run, daemon=True)
+    PROCESSES.append(p_exchange)
     p_exchange.start()
 
     # We need to import this after spawning the web server
@@ -69,8 +87,17 @@ def start():
 
     setproctitle.setproctitle('bigchaindb')
 
+    # Start the ABCIServer and watch for signals to stop
+    # the server and the relevant child processes.
     app = ABCIServer(app=App())
-    app.run()
+    gevent.signal(signal.SIGTERM, sig_handler, app.server)
+    gevent.signal(signal.SIGQUIT, sig_handler, app.server)
+    gevent.signal(signal.SIGINT, sig_handler, app.server)
+
+    app.server.serve_forever()
+
+    for p in PROCESSES:
+        p.join()
 
 
 if __name__ == '__main__':