From 2e54e695d84b0d7eecc62af7c574e58cc82b837a Mon Sep 17 00:00:00 2001
From: Alex Harris <122488678+aleexharris@users.noreply.github.com>
Date: Tue, 29 Oct 2024 19:54:19 +0000
Subject: [PATCH] Fix: Docker Compose Example (#25546)

## Summary & Motivation

Docker Compose example deployment for Dagster throws errors on
initialisation because the webserver and daemon do not wait for the
postgreSQL database to be ready before attempting to connect.

Added healthcheck to postgresql container to fix this issue.

## How I Tested These Changes

Works on my machine and a new EC2 instance with relevant bits installed.
---
 examples/deploy_docker/docker-compose.yml | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/examples/deploy_docker/docker-compose.yml b/examples/deploy_docker/docker-compose.yml
index 61b1cd633d8ad..67eed4bf80089 100644
--- a/examples/deploy_docker/docker-compose.yml
+++ b/examples/deploy_docker/docker-compose.yml
@@ -2,7 +2,8 @@ version: "3.7"
 
 services:
   # This service runs the postgres DB used by dagster for run storage, schedule storage,
-  # and event log storage.
+  # and event log storage. Depending on the hardware you run this Compose on, you may be able
+  # to reduce the interval and timeout in the healthcheck to speed up your `docker-compose up` times.
   docker_example_postgresql:
     image: postgres:11
     container_name: docker_example_postgresql
@@ -12,6 +13,11 @@ services:
       POSTGRES_DB: "postgres_db"
     networks:
       - docker_example_network
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U postgres_user -d postgres_db"]
+      interval: 10s
+      timeout: 8s
+      retries: 5
 
   # This service runs the gRPC server that loads your user code, in both dagster-webserver
   # and dagster-daemon. By setting DAGSTER_CURRENT_IMAGE to its own image, we tell the
@@ -64,8 +70,10 @@ services:
     networks:
       - docker_example_network
     depends_on:
-      - docker_example_postgresql
-      - docker_example_user_code
+      docker_example_postgresql:
+        condition: service_healthy
+      docker_example_user_code:
+        condition: service_started
 
   # This service runs the dagster-daemon process, which is responsible for taking runs
   # off of the queue and launching them, as well as creating runs from schedules or sensors.
@@ -88,8 +96,10 @@ services:
     networks:
       - docker_example_network
     depends_on:
-      - docker_example_postgresql
-      - docker_example_user_code
+      docker_example_postgresql:
+        condition: service_healthy
+      docker_example_user_code:
+        condition: service_started
 
 networks:
   docker_example_network: