Implemented python tests with pytest (#790)

Currently the python tests act as scripts. A lot of output is generated to stdout which makes it very hard to figure out where problems were. Also if you want to run only a single test you basically need to comment out code in order to accomplish this.

This PR modifies the python tests to us the pytest python testing framework. This framework allows individual tests to be targeted via the command line, without touching the source code. It also suppressed stdout by default making the test output much easier to read. Also after the tests run it will provide a summary of what failed, what succeded, etc.


Co-authored-by: CommanderKeynes <andrewjackson947@gmail.coma>
Co-authored-by: Andrew Jackson <andrewjackson2988@gmail.com>

.circleci/run_tests.sh

@@ -107,7 +107,7 @@ cd ../..
 # These tests will start and stop the pgcat server so it will need to be restarted after the tests
 #
 pip3 install -r tests/python/requirements.txt
-python3 tests/python/tests.py || exit 1
+pytest || exit 1
 
 
 #

.gitignore

@@ -10,4 +10,5 @@ lcov.info
 dev/.bash_history
 dev/cache
 !dev/cache/.keepme
-.venv
+.venv
+**/__pycache__

CONTRIBUTING.md

@@ -7,7 +7,7 @@ Thank you for contributing! Just a few tips here:
 3. Performance is important, make sure there are no regressions in your branch vs. `main`.
 
 ## How to run the integration tests locally and iterate on them
-We have integration tests written in Ruby, Python, Go and Rust. 
+We have integration tests written in Ruby, Python, Go and Rust.
 Below are the steps to run them in a developer-friendly way that allows iterating and quick turnaround.
 Hear me out, this should be easy, it will involve opening a shell into a container with all the necessary dependancies available for you and you can modify the test code and immediately rerun your test in the interactive shell.
 
@@ -21,7 +21,7 @@ Within this test environment you can modify the file in your favorite IDE and re
 
 Once the environment is ready, you can run the tests by running
 Ruby:   `cd /app/tests/ruby && bundle exec ruby <test_name>.rb --format documentation`
-Python: `cd /app && python3 tests/python/tests.py`
+Python: `cd /app/ && pytest`
 Rust:   `cd /app/tests/rust && cargo run`
 Go:     `cd /app/tests/go && /usr/local/go/bin/go test`
 

start_test_env.sh

@@ -23,11 +23,11 @@ docker compose exec --workdir /app/tests/python main pip3 install -r requirement
 echo "Interactive test environment ready"
 echo "To run integration tests, you can use the following commands:"
 echo -e "   ${BLUE}Ruby:   ${RED}cd /app/tests/ruby && bundle exec ruby tests.rb --format documentation${RESET}"
-echo -e "   ${BLUE}Python: ${RED}cd /app && python3 tests/python/tests.py${RESET}"
+echo -e "   ${BLUE}Python: ${RED}cd /app/ && pytest ${RESET}"
 echo -e "   ${BLUE}Rust:   ${RED}cd /app/tests/rust && cargo run ${RESET}"
 echo -e "   ${BLUE}Go:     ${RED}cd /app/tests/go && /usr/local/go/bin/go test${RESET}"
 echo "the source code for tests are directly linked to the source code in the container so you can modify the code and run the tests again"
-echo "You can rebuild PgCat from within the container by running" 
+echo "You can rebuild PgCat from within the container by running"
 echo -e "  ${GREEN}cargo build${RESET}"
 echo "and then run the tests again"
 echo "==================================="

tests/python/requirements.txt

@@ -1,2 +1,3 @@
+pytest
 psycopg2==2.9.3
-psutil==5.9.1
+psutil==5.9.1

tests/python/test_pgcat.py

@@ -1,83 +1,29 @@
-from typing import Tuple
-import psycopg2
-import psutil
 import os
 import signal
 import time
 
+import psycopg2
+
+import utils
+
 SHUTDOWN_TIMEOUT = 5
 
-PGCAT_HOST = "127.0.0.1"
-PGCAT_PORT = "6432"
-
-
-def pgcat_start():
-    pg_cat_send_signal(signal.SIGTERM)
-    os.system("./target/debug/pgcat .circleci/pgcat.toml &")
-    time.sleep(2)
-
-
-def pg_cat_send_signal(signal: signal.Signals):
-    try:
-        for proc in psutil.process_iter(["pid", "name"]):
-            if "pgcat" == proc.name():
-                os.kill(proc.pid, signal)
-    except Exception as e:
-        # The process can be gone when we send this signal
-        print(e)
-
-    if signal == signal.SIGTERM:
-        # Returns 0 if pgcat process exists
-        time.sleep(2)
-        if not os.system('pgrep pgcat'):
-            raise Exception("pgcat not closed after SIGTERM")
-
-
-def connect_db(
-    autocommit: bool = True,
-    admin: bool = False,
-) -> Tuple[psycopg2.extensions.connection, psycopg2.extensions.cursor]:
-
-    if admin:
-        user = "admin_user"
-        password = "admin_pass"
-        db = "pgcat"
-    else:
-        user = "sharding_user"
-        password = "sharding_user"
-        db = "sharded_db"
-
-    conn = psycopg2.connect(
-        f"postgres://{user}:{password}@{PGCAT_HOST}:{PGCAT_PORT}/{db}?application_name=testing_pgcat",
-        connect_timeout=2,
-    )
-    conn.autocommit = autocommit
-    cur = conn.cursor()
-
-    return (conn, cur)
-
-
-def cleanup_conn(conn: psycopg2.extensions.connection, cur: psycopg2.extensions.cursor):
-    cur.close()
-    conn.close()
-
-
 def test_normal_db_access():
-    pgcat_start()
-    conn, cur = connect_db(autocommit=False)
+    utils.pgcat_start()
+    conn, cur = utils.connect_db(autocommit=False)
     cur.execute("SELECT 1")
     res = cur.fetchall()
     print(res)
-    cleanup_conn(conn, cur)
+    utils.cleanup_conn(conn, cur)
 
 
 def test_admin_db_access():
-    conn, cur = connect_db(admin=True)
+    conn, cur = utils.connect_db(admin=True)
 
     cur.execute("SHOW POOLS")
     res = cur.fetchall()
     print(res)
-    cleanup_conn(conn, cur)
+    utils.cleanup_conn(conn, cur)
 
 
 def test_shutdown_logic():
@@ -86,17 +32,17 @@ def test_shutdown_logic():
     # NO ACTIVE QUERIES SIGINT HANDLING
 
     # Start pgcat
-    pgcat_start()
+    utils.pgcat_start()
 
     # Create client connection and send query (not in transaction)
-    conn, cur = connect_db()
+    conn, cur = utils.connect_db()
 
     cur.execute("BEGIN;")
     cur.execute("SELECT 1;")
     cur.execute("COMMIT;")
 
     # Send sigint to pgcat
-    pg_cat_send_signal(signal.SIGINT)
+    utils.pg_cat_send_signal(signal.SIGINT)
     time.sleep(1)
 
     # Check that any new queries fail after sigint since server should close with no active transactions
@@ -108,18 +54,18 @@ def test_shutdown_logic():
         # Fail if query execution succeeded
         raise Exception("Server not closed after sigint")
 
-    cleanup_conn(conn, cur)
-    pg_cat_send_signal(signal.SIGTERM)
+    utils.cleanup_conn(conn, cur)
+    utils.pg_cat_send_signal(signal.SIGTERM)
 
     # - - - - - - - - - - - - - - - - - -
     # NO ACTIVE QUERIES ADMIN SHUTDOWN COMMAND
 
     # Start pgcat
-    pgcat_start()
+    utils.pgcat_start()
 
     # Create client connection and begin transaction
-    conn, cur = connect_db()
-    admin_conn, admin_cur = connect_db(admin=True)
+    conn, cur = utils.connect_db()
+    admin_conn, admin_cur = utils.connect_db(admin=True)
 
     cur.execute("BEGIN;")
     cur.execute("SELECT 1;")
@@ -138,24 +84,24 @@ def test_shutdown_logic():
         # Fail if query execution succeeded
         raise Exception("Server not closed after sigint")
 
-    cleanup_conn(conn, cur)
-    cleanup_conn(admin_conn, admin_cur)
-    pg_cat_send_signal(signal.SIGTERM)
+    utils.cleanup_conn(conn, cur)
+    utils.cleanup_conn(admin_conn, admin_cur)
+    utils.pg_cat_send_signal(signal.SIGTERM)
 
     # - - - - - - - - - - - - - - - - - -
     # HANDLE TRANSACTION WITH SIGINT
 
     # Start pgcat
-    pgcat_start()
+    utils.pgcat_start()
 
     # Create client connection and begin transaction
-    conn, cur = connect_db()
+    conn, cur = utils.connect_db()
 
     cur.execute("BEGIN;")
     cur.execute("SELECT 1;")
 
     # Send sigint to pgcat while still in transaction
-    pg_cat_send_signal(signal.SIGINT)
+    utils.pg_cat_send_signal(signal.SIGINT)
     time.sleep(1)
 
     # Check that any new queries succeed after sigint since server should still allow transaction to complete
@@ -165,18 +111,18 @@ def test_shutdown_logic():
         # Fail if query fails since server closed
         raise Exception("Server closed while in transaction", e.pgerror)
 
-    cleanup_conn(conn, cur)
-    pg_cat_send_signal(signal.SIGTERM)
+    utils.cleanup_conn(conn, cur)
+    utils.pg_cat_send_signal(signal.SIGTERM)
 
     # - - - - - - - - - - - - - - - - - -
     # HANDLE TRANSACTION WITH ADMIN SHUTDOWN COMMAND
 
     # Start pgcat
-    pgcat_start()
+    utils.pgcat_start()
 
     # Create client connection and begin transaction
-    conn, cur = connect_db()
-    admin_conn, admin_cur = connect_db(admin=True)
+    conn, cur = utils.connect_db()
+    admin_conn, admin_cur = utils.connect_db(admin=True)
 
     cur.execute("BEGIN;")
     cur.execute("SELECT 1;")
@@ -194,30 +140,30 @@ def test_shutdown_logic():
         # Fail if query fails since server closed
         raise Exception("Server closed while in transaction", e.pgerror)
 
-    cleanup_conn(conn, cur)
-    cleanup_conn(admin_conn, admin_cur)
-    pg_cat_send_signal(signal.SIGTERM)
+    utils.cleanup_conn(conn, cur)
+    utils.cleanup_conn(admin_conn, admin_cur)
+    utils.pg_cat_send_signal(signal.SIGTERM)
 
     # - - - - - - - - - - - - - - - - - -
     # NO NEW NON-ADMIN CONNECTIONS DURING SHUTDOWN
     # Start pgcat
-    pgcat_start()
+    utils.pgcat_start()
 
     # Create client connection and begin transaction
-    transaction_conn, transaction_cur = connect_db()
+    transaction_conn, transaction_cur = utils.connect_db()
 
     transaction_cur.execute("BEGIN;")
     transaction_cur.execute("SELECT 1;")
 
     # Send sigint to pgcat while still in transaction
-    pg_cat_send_signal(signal.SIGINT)
+    utils.pg_cat_send_signal(signal.SIGINT)
     time.sleep(1)
 
     start = time.perf_counter()
     try:
-        conn, cur = connect_db()
+        conn, cur = utils.connect_db()
         cur.execute("SELECT 1;")
-        cleanup_conn(conn, cur)
+        utils.cleanup_conn(conn, cur)
     except psycopg2.OperationalError as e:
         time_taken = time.perf_counter() - start
         if time_taken > 0.1:
@@ -227,49 +173,49 @@ def test_shutdown_logic():
     else:
         raise Exception("Able connect to database during shutdown")
 
-    cleanup_conn(transaction_conn, transaction_cur)
-    pg_cat_send_signal(signal.SIGTERM)
+    utils.cleanup_conn(transaction_conn, transaction_cur)
+    utils.pg_cat_send_signal(signal.SIGTERM)
 
     # - - - - - - - - - - - - - - - - - -
     # ALLOW NEW ADMIN CONNECTIONS DURING SHUTDOWN
     # Start pgcat
-    pgcat_start()
+    utils.pgcat_start()
 
     # Create client connection and begin transaction
-    transaction_conn, transaction_cur = connect_db()
+    transaction_conn, transaction_cur = utils.connect_db()
 
     transaction_cur.execute("BEGIN;")
     transaction_cur.execute("SELECT 1;")
 
     # Send sigint to pgcat while still in transaction
-    pg_cat_send_signal(signal.SIGINT)
+    utils.pg_cat_send_signal(signal.SIGINT)
     time.sleep(1)
 
     try:
-        conn, cur = connect_db(admin=True)
+        conn, cur = utils.connect_db(admin=True)
         cur.execute("SHOW DATABASES;")
-        cleanup_conn(conn, cur)
+        utils.cleanup_conn(conn, cur)
     except psycopg2.OperationalError as e:
         raise Exception(e)
 
-    cleanup_conn(transaction_conn, transaction_cur)
-    pg_cat_send_signal(signal.SIGTERM)
+    utils.cleanup_conn(transaction_conn, transaction_cur)
+    utils.pg_cat_send_signal(signal.SIGTERM)
 
     # - - - - - - - - - - - - - - - - - -
     # ADMIN CONNECTIONS CONTINUING TO WORK AFTER SHUTDOWN
     # Start pgcat
-    pgcat_start()
+    utils.pgcat_start()
 
     # Create client connection and begin transaction
-    transaction_conn, transaction_cur = connect_db()
+    transaction_conn, transaction_cur = utils.connect_db()
     transaction_cur.execute("BEGIN;")
     transaction_cur.execute("SELECT 1;")
 
-    admin_conn, admin_cur = connect_db(admin=True)
+    admin_conn, admin_cur = utils.connect_db(admin=True)
     admin_cur.execute("SHOW DATABASES;")
 
     # Send sigint to pgcat while still in transaction
-    pg_cat_send_signal(signal.SIGINT)
+    utils.pg_cat_send_signal(signal.SIGINT)
     time.sleep(1)
 
     try:
@@ -277,24 +223,24 @@ def test_shutdown_logic():
     except psycopg2.OperationalError as e:
         raise Exception("Could not execute admin command:", e)
 
-    cleanup_conn(transaction_conn, transaction_cur)
-    cleanup_conn(admin_conn, admin_cur)
-    pg_cat_send_signal(signal.SIGTERM)
+    utils.cleanup_conn(transaction_conn, transaction_cur)
+    utils.cleanup_conn(admin_conn, admin_cur)
+    utils.pg_cat_send_signal(signal.SIGTERM)
 
     # - - - - - - - - - - - - - - - - - -
     # HANDLE SHUTDOWN TIMEOUT WITH SIGINT
 
     # Start pgcat
-    pgcat_start()
+    utils.pgcat_start()
 
     # Create client connection and begin transaction, which should prevent server shutdown unless shutdown timeout is reached
-    conn, cur = connect_db()
+    conn, cur = utils.connect_db()
 
     cur.execute("BEGIN;")
     cur.execute("SELECT 1;")
 
     # Send sigint to pgcat while still in transaction
-    pg_cat_send_signal(signal.SIGINT)
+    utils.pg_cat_send_signal(signal.SIGINT)
 
     # pgcat shutdown timeout is set to SHUTDOWN_TIMEOUT seconds, so we sleep for SHUTDOWN_TIMEOUT + 1 seconds
     time.sleep(SHUTDOWN_TIMEOUT + 1)
@@ -308,12 +254,5 @@ def test_shutdown_logic():
         # Fail if query execution succeeded
         raise Exception("Server not closed after sigint and expected timeout")
 
-    cleanup_conn(conn, cur)
-    pg_cat_send_signal(signal.SIGTERM)
-
-    # - - - - - - - - - - - - - - - - - -
-
-
-test_normal_db_access()
-test_admin_db_access()
-test_shutdown_logic()
+    utils.cleanup_conn(conn, cur)
+    utils.pg_cat_send_signal(signal.SIGTERM)

tests/python/utils.py

@@ -0,0 +1,60 @@
+from typing import Tuple
+import os
+import psutil
+import signal
+import time
+
+import psycopg2
+
+PGCAT_HOST = "127.0.0.1"
+PGCAT_PORT = "6432"
+
+def pgcat_start():
+    pg_cat_send_signal(signal.SIGTERM)
+    os.system("./target/debug/pgcat .circleci/pgcat.toml &")
+    time.sleep(2)
+
+
+def pg_cat_send_signal(signal: signal.Signals):
+    try:
+        for proc in psutil.process_iter(["pid", "name"]):
+            if "pgcat" == proc.name():
+                os.kill(proc.pid, signal)
+    except Exception as e:
+        # The process can be gone when we send this signal
+        print(e)
+
+    if signal == signal.SIGTERM:
+        # Returns 0 if pgcat process exists
+        time.sleep(2)
+        if not os.system('pgrep pgcat'):
+            raise Exception("pgcat not closed after SIGTERM")
+
+
+def connect_db(
+    autocommit: bool = True,
+    admin: bool = False,
+) -> Tuple[psycopg2.extensions.connection, psycopg2.extensions.cursor]:
+
+    if admin:
+        user = "admin_user"
+        password = "admin_pass"
+        db = "pgcat"
+    else:
+        user = "sharding_user"
+        password = "sharding_user"
+        db = "sharded_db"
+
+    conn = psycopg2.connect(
+        f"postgres://{user}:{password}@{PGCAT_HOST}:{PGCAT_PORT}/{db}?application_name=testing_pgcat",
+        connect_timeout=2,
+    )
+    conn.autocommit = autocommit
+    cur = conn.cursor()
+
+    return (conn, cur)
+
+
+def cleanup_conn(conn: psycopg2.extensions.connection, cur: psycopg2.extensions.cursor):
+    cur.close()
+    conn.close()