Implementing graceful shutdown (#105)

* Initial commit for graceful shutdown

* fmt

* Add .vscode to gitignore

* Updates shutdown logic to use channels

* fmt

* fmt

* Adds shutdown timeout

* Fmt and updates tomls

* Updates readme

* fmt and updates log levels

* Update python tests to test shutdown

* merge changes

* Rename listener rx and update bash to be in line with master

* Update python test bash script ordering

* Adds error response message before shutdown

* Add details on shutdown event loop

* Fixes response length for error

* Adds handler for sigterm

* Uses ready for query function and fixes number of bytes

* fmt

.circleci/pgcat.toml

@@ -17,6 +17,9 @@ connect_timeout = 100
 # How much time to give the health check query to return with a result (ms).
 healthcheck_timeout = 100
 
+# How much time to give clients during shutdown before forcibly killing client connections (ms).
+shutdown_timeout = 5000
+
 # For how long to ban a server if it fails a health check (seconds).
 ban_time = 60 # Seconds
 

.circleci/run_tests.sh

@@ -74,12 +74,12 @@ cd ../..
 
 #
 # Python tests
+# These tests will start and stop the pgcat server so it will need to be restarted after the tests
 #
-cd tests/python
-pip3 install -r requirements.txt
-python3 tests.py
-cd ../..
+pip3 install -r tests/python/requirements.txt
+python3 tests/python/tests.py
 
+start_pgcat "info"
 
 # Admin tests
 export PGPASSWORD=admin_pass