OBS-410: Add script for graceful gunicorn shutdown. (#3082)

bin/run_web.sh

@@ -8,6 +8,7 @@
 : "${PORT:=8000}"
 : "${GUNICORN_WORKERS:=4}"
 : "${GUNICORN_TIMEOUT:=600}"
+: "${GUNICORN_GRACEFUL_TIMEOUT:=600}"
 
 export PROCESS_NAME=webapp
 
@@ -20,8 +21,10 @@ else
     echo "GUNICORN_TIMEOUT=${GUNICORN_TIMEOUT}"
     echo "PORT=${PORT}"
     ${CMD_PREFIX} gunicorn \
+        --pid /tmp/gunicorn.pid \
         --bind 0.0.0.0:"${PORT}" \
         --timeout "${GUNICORN_TIMEOUT}" \
+        --graceful-timeout "${GUNICORN_GRACEFUL_TIMEOUT}" \
         --workers "${GUNICORN_WORKERS}" \
         --config=tecken/gunicornhooks.py \
         --access-logfile - \

bin/stop_gunicorn.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+
+# Send the TERM signal to gunicorn to trigger a graceful shutdown, and wait for it to exit.
+
+set -euo pipefail
+
+pid=`cat /tmp/gunicorn.pid`
+
+if [ -n "$pid" ]; then
+    echo "Sending TERM signal to gunicorn."
+    kill -TERM "$pid"
+    echo "Waiting for gunicorn to exit..."
+    while kill -0 $pid 2>/dev/null; do
+        sleep 1
+    done
+fi