Optimize DB connections and unify container boot with migrations

Add connection pooling (CONN_MAX_AGE=600, CONN_HEALTH_CHECKS) to avoid DNS re-resolution and Postgres handshakes on every request. Refactor entrypoint.sh to run migrations on all container boots (web, workers, scheduler) so

Author: JobDoesburg

Dockerfile

@@ -38,5 +38,6 @@ RUN mkdir -p $DJANGO_STATIC_ROOT $DJANGO_MEDIA_ROOT \
 
 EXPOSE 80
 
-# Command to run uWSGI
-CMD ["/bin/sh", "/entrypoint.sh"]
+# entrypoint.sh runs migrations, then either execs uWSGI (no args) or the
+# command passed via Compose `command:` (workers, scheduler, manage.py ...).
+ENTRYPOINT ["/bin/sh", "/entrypoint.sh"]

deploy/docker-compose.yml

@@ -122,7 +122,11 @@ services:
       interval: 10s
       timeout: 5s
       retries: 5
-      start_period: 60s
+      # Generous window: every Django container now runs `migrate` on boot
+      # (via entrypoint.sh) and only one acquires Django's advisory lock;
+      # the others block. With three services and a growing schema, cold
+      # boot can take >60s.
+      start_period: 180s
 
   task-worker:
     image: *landolfio-image

entrypoint.sh

@@ -1,14 +1,23 @@
 #!/bin/sh
+# Common boot for every Django container: web, task-worker, task-scheduler.
+# Apply migrations first so workers don't race the schema. Then dispatch:
+#   - no argv  → web (uWSGI)
+#   - any argv → exec it (worker / scheduler / one-off command)
+set -e
+
 python manage.py migrate --noinput
 
+if [ "$#" -gt 0 ]; then
+    exec "$@"
+fi
+
 # Ensure the uWSGI logfile exists so tail -F doesn't print a spurious warning.
 touch /var/log/uwsgi.log
 
 # Stream uWSGI logs to stdout for `docker logs`.
 tail -F /var/log/uwsgi.log &
 
-# Start uWSGI (logs go to both file and stdout)
-uwsgi --http :80 \
+exec uwsgi --http :80 \
       --wsgi-file /app/website/wsgi.py \
       --master \
       --processes 4 \

landolfio/website/settings/production.py

@@ -42,6 +42,12 @@
         "PASSWORD": os.environ.get("POSTGRES_PASSWORD"),
         "HOST": os.environ.get("POSTGRES_HOST"),
         "PORT": os.environ.get("POSTGRES_PORT"),
+        # Keep DB connections warm so we don't re-resolve `database` DNS
+        # and re-handshake Postgres on every request. Health-checks the
+        # cached connection cheaply before reuse, so a stale socket from
+        # a Postgres restart drops cleanly instead of erroring out.
+        "CONN_MAX_AGE": 600,
+        "CONN_HEALTH_CHECKS": True,
     }
 }