From b664cb33c4f213851619b34754e6d2b95cdcc814 Mon Sep 17 00:00:00 2001
From: Keannu Bernasol <noehbernasol0@gmail.com>
Date: Thu, 5 Sep 2024 13:16:23 +0800
Subject: [PATCH] Add native PgBouncer support to alleviate DB connection limit
 errors

---
 .env.sample                |  5 ++++-
 backend/config/settings.py | 18 ++++++++++++++----
 docker-compose.demo.yml    | 13 +++++++++++--
 docker-compose.dev.yml     | 23 +++++++++++++++++++----
 4 files changed, 48 insertions(+), 11 deletions(-)

diff --git a/.env.sample b/.env.sample
index 021b6f6..0658d59 100644
--- a/.env.sample
+++ b/.env.sample
@@ -27,7 +27,10 @@ DB_PASSWORD = ''
 DB_HOST = 'postgres'
 DB_PORT = '5432'
 DB_SSL_MODE = 'disable'
-DB_DISABLE_SERVER_SIDE_CURSORS = 'False' # If you're using an external connection bouncer (eg. PgBouncer), set this to True
+# DB connection bouncer
+USE_BOUNCER = 'True'
+DB_BOUNCER_HOST = 'pgbouncer'
+DB_BOUNCER_PORT = '6432'
 
 # Redis
 # Used for DB cache and Celery broker
diff --git a/backend/config/settings.py b/backend/config/settings.py
index bfd5707..514e5b1 100644
--- a/backend/config/settings.py
+++ b/backend/config/settings.py
@@ -223,16 +223,26 @@ SPECTACULAR_SETTINGS = {
 
 WSGI_APPLICATION = 'config.wsgi.application'
 
+# If you're using an external connection bouncer (eg. PgBouncer), server side cursors must be disabled to avoid any issues
+USE_BOUNCER = get_secret("USE_BOUNCER")
+if USE_BOUNCER:
+    DISABLE_SERVER_SIDE_CURSORS = True
+    DB_HOST = get_secret("DB_BOUNCER_HOST")
+    DB_PORT = get_secret("DB_BOUNCER_PORT")
+else:
+    DISABLE_SERVER_SIDE_CURSORS = False
+    DB_HOST = get_secret("DB_HOST")
+    DB_PORT = get_secret("DB_PORT")
+
 DATABASES = {
     "default": {
         "ENGINE": "django.db.backends.postgresql",
-        # Set to True to avoid issues with pgbouncer when pooling connections
-        'DISABLE_SERVER_SIDE_CURSORS': get_secret("DB_DISABLE_SERVER_SIDE_CURSORS"),
+        'DISABLE_SERVER_SIDE_CURSORS': DISABLE_SERVER_SIDE_CURSORS,
         "NAME": get_secret("DB_DATABASE"),
         "USER": get_secret("DB_USERNAME"),
         "PASSWORD": get_secret("DB_PASSWORD"),
-        "HOST": get_secret("DB_HOST"),
-        "PORT": get_secret("DB_PORT"),
+        "HOST": DB_HOST,
+        "PORT": DB_PORT,
         "OPTIONS": {
             "sslmode": get_secret("DB_SSL_MODE")
         },
diff --git a/docker-compose.demo.yml b/docker-compose.demo.yml
index eeb09d9..bbc5326 100644
--- a/docker-compose.demo.yml
+++ b/docker-compose.demo.yml
@@ -51,11 +51,20 @@ services:
     volumes:
       - db-data:/var/lib/postgresql/data
 
+  # DB Bouncer
+  pgbouncer:
+    image: bitnami/pgbouncer:latest
+    environment:
+      - POSTGRESQL_HOST=postgres
+      - PGBOUNCER_DATABASE=${DB_DATABASE}
+      - POSTGRESQL_USERNAME=${DB_USERNAME}
+      - POSTGRESQL_PASSWORD=${DB_PASSWORD}
+    depends_on:
+      - postgres
+
   # Redis Server
   redis:
     image: redis:latest
-    ports:
-      - "${REDIS_PORT}:6379"
 
   # Stripe CLI Webhook Listener
   stripe-listener:
diff --git a/docker-compose.dev.yml b/docker-compose.dev.yml
index b5a63e8..58fc5ab 100644
--- a/docker-compose.dev.yml
+++ b/docker-compose.dev.yml
@@ -17,6 +17,8 @@ services:
       - .:/code
     depends_on:
       - postgres
+      - pgbouncer
+      - redis
 
   # Django Celery Worker
   celery:
@@ -32,6 +34,7 @@ services:
     depends_on:
       - django
       - postgres
+      - pgbouncer
       - redis
     # Runs multiple worker instances
     scale: 4
@@ -45,9 +48,10 @@ services:
     volumes:
       - .:/code
     depends_on:
-      - celery
       - django
+      - celery
       - postgres
+      - pgbouncer
       - redis
 
   # Django Celery Monitor
@@ -62,8 +66,10 @@ services:
     volumes:
       - .:/code
     depends_on:
-      - celery
       - django
+      - celery
+      - postgres
+      - pgbouncer
       - redis
 
   # SQL Database
@@ -77,11 +83,20 @@ services:
     volumes:
       - db-data:/var/lib/postgresql/data
 
+  # DB Bouncer
+  pgbouncer:
+    image: bitnami/pgbouncer:latest
+    environment:
+      - POSTGRESQL_HOST=postgres
+      - PGBOUNCER_DATABASE=${DB_DATABASE}
+      - POSTGRESQL_USERNAME=${DB_USERNAME}
+      - POSTGRESQL_PASSWORD=${DB_PASSWORD}
+    depends_on:
+      - postgres
+
   # Redis Server
   redis:
     image: redis:latest
-    ports:
-      - "${REDIS_PORT}:6379"
 
   # Stripe CLI Webhook Listener
   stripe-listener: