Merge pull request #485 from DefangLabs/fastapi-postgres-pubsub

FastAPI Postgres PubSub

Author: raphaeltm

.github/workflows/deploy-changed-samples.yml

@@ -102,6 +102,7 @@ jobs:
           TEST_SLACK_CHANNEL_ID: ${{ secrets.TEST_SLACK_CHANNEL_ID }}
           TEST_SLACK_TOKEN: ${{ secrets.TEST_SLACK_TOKEN }}
           TEST_SHARED_SECRETS: ${{ secrets.TEST_SHARED_SECRETS}}
+          TEST_SSL_MODE: ${{ secrets.TEST_SSL_MODE }}
           TEST_TAVILY_API_KEY: ${{ secrets.TEST_TAVILY_API_KEY }}
           TEST_ALLOWED_HOSTS: ${{ secrets.TEST_ALLOWED_HOSTS }}
         run: |

samples/fastapi-postgres-pubsub/.devcontainer/Dockerfile

@@ -0,0 +1 @@
+FROM mcr.microsoft.com/devcontainers/python:3.12-bookworm

samples/fastapi-postgres-pubsub/.devcontainer/devcontainer.json

@@ -0,0 +1,11 @@
+{
+  "build": {
+    "dockerfile": "Dockerfile",
+    "context": ".."
+  },
+  "features": {
+    "ghcr.io/defanglabs/devcontainer-feature/defang-cli:1.0.4": {},
+    "ghcr.io/devcontainers/features/docker-in-docker:2": {},
+    "ghcr.io/devcontainers/features/aws-cli:1": {}
+  }
+}

samples/fastapi-postgres-pubsub/.github/workflows/deploy.yaml

@@ -0,0 +1,26 @@
+name: Deploy
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  deploy:
+    environment: playground
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      id-token: write
+
+    steps:
+    - name: Checkout Repo
+      uses: actions/checkout@v4
+
+    - name: Deploy
+      uses: DefangLabs/[email protected]
+      with:
+        config-env-vars: POSTGRES_PASSWORD SSL_MODE
+      env:
+        POSTGRES_PASSWORD: ${{ secrets.POSTGRES_PASSWORD }}
+        SSL_MODE: ${{ secrets.SSL_MODE }}

samples/fastapi-postgres-pubsub/README.md

@@ -0,0 +1,71 @@
+# FastAPI Postgres Pub/Sub Chat
+
+[![1-click-deploy](https://raw.githubusercontent.com/DefangLabs/defang-assets/main/Logos/Buttons/SVG/deploy-with-defang.svg)](https://portal.defang.dev/redirect?url=https%3A%2F%2Fgithub.com%2Fnew%3Ftemplate_name%3Dsample-fastapi-postgres-pubsub-template%26template_owner%3DDefangSamples)
+
+This sample pairs FastAPI with PostgreSQL `LISTEN/NOTIFY` to demonstrate real-time updates between two application containers. A minimal chat UI sends messages with a REST request, and both FastAPI instances broadcast the new message over WebSockets after Postgres notifies them.
+
+## Prerequisites
+
+1. Download [Defang CLI](https://github.com/DefangLabs/defang)
+2. (Optional) If you are using [Defang BYOC](https://docs.defang.io/docs/concepts/defang-byoc) authenticate with your cloud provider account
+3. (Optional for local development) [Docker CLI](https://docs.docker.com/engine/install/)
+
+## Development
+
+To run the application locally, you can use the following command:
+
+```bash
+docker compose -f compose.dev.yaml up --build
+```
+
+Once everything is running:
+- Visit [http://localhost:8000](http://localhost:8000) for the first FastAPI service.
+- Visit [http://localhost:8001](http://localhost:8001) for the second service.
+- Send a chat message in either window. Both pages should update immediately, proving Postgres `LISTEN/NOTIFY` fans the event across containers.
+
+Stop the stack with `Ctrl+C`, then run `docker compose -f compose.dev.yaml down`.
+
+## Configuration
+
+For this sample, you can rely on the defaults. Override them with environment variables if needed:
+
+> Note that if you are using the 1-click deploy option, you can set these values as secrets in your GitHub repository and the action will automatically deploy them for you.
+
+### `POSTGRES_PASSWORD`
+Database password (default `chat_password`).
+```bash
+defang config set POSTGRES_PASSWORD --random
+```
+
+### `SSL_MODE`
+
+Postgres SSL mode (default `disable`, should set to `require` in production).
+```bash
+defang config set SSL_MODE=require
+```
+
+## Deployment
+
+> [!NOTE]
+> Download [Defang CLI](https://github.com/DefangLabs/defang)
+
+### Defang Playground
+
+Deploy your application to the Defang Playground by opening up your terminal and typing:
+```bash
+defang compose up
+```
+
+### BYOC
+
+If you want to deploy to your own cloud account, you can [use Defang BYOC](https://docs.defang.io/docs/tutorials/deploy-to-your-cloud).
+
+---
+
+Title: FastAPI Postgres Pub/Sub
+
+Short Description: FastAPI sample that stores messages in Postgres and streams them to two app instances via LISTEN/NOTIFY.
+
+Tags: FastAPI, PostgreSQL, WebSockets, PubSub
+
+Languages: Python, SQL

samples/fastapi-postgres-pubsub/app/.gitignore

@@ -0,0 +1,3 @@
+.venv
+.env
+

samples/fastapi-postgres-pubsub/app/Dockerfile

@@ -0,0 +1,20 @@
+FROM python:3.11-slim
+
+ENV PYTHONUNBUFFERED=1
+ENV PYTHONDONTWRITEBYTECODE=1
+
+WORKDIR /app
+
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends build-essential libpq-dev curl \
+    && rm -rf /var/lib/apt/lists/*
+
+COPY requirements.txt ./
+RUN pip install --no-cache-dir --upgrade pip \
+    && pip install --no-cache-dir -r requirements.txt
+
+COPY . .
+
+EXPOSE 8000
+
+CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"]