Google App Engine

Status: Production Ready Last Updated: 2026-01-24 Dependencies: Google Cloud SDK (gcloud CLI) Skill Version: 1.0.0

Quick Start (10 Minutes)

1. Prerequisites

# Install Google Cloud SDK
# macOS
brew install google-cloud-sdk

# Or download from https://cloud.google.com/sdk/docs/install

# Authenticate
gcloud auth login
gcloud config set project YOUR_PROJECT_ID

# Enable required APIs
gcloud services enable appengine.googleapis.com
gcloud services enable sqladmin.googleapis.com
gcloud services enable secretmanager.googleapis.com

2. Create app.yaml

# app.yaml - Standard Environment (Python 3.12)
runtime: python312
instance_class: F2

env_variables:
  DJANGO_SETTINGS_MODULE: "myproject.settings.production"

handlers:
  # Static files (served directly by App Engine)
  - url: /static
    static_dir: staticfiles/
    secure: always

  # All other requests go to the app
  - url: /.*
    script: auto
    secure: always

automatic_scaling:
  min_instances: 0
  max_instances: 10
  target_cpu_utilization: 0.65

3. Deploy

# Deploy to App Engine
gcloud app deploy

# Deploy with specific version
gcloud app deploy --version=v1 --no-promote

# View logs
gcloud app logs tail -s default

Standard vs Flexible Environment

Standard Environment (Recommended for Most Apps)

Use when: Building typical web apps, APIs, or services that fit within runtime constraints.

# app.yaml - Standard
runtime: python312
instance_class: F2

Flexible Environment

Use when: Need custom runtimes, Docker, longer request timeouts, or background threads.

# app.yaml - Flexible
runtime: python
env: flex

runtime_config:
  runtime_version: "3.12"

resources:
  cpu: 1
  memory_gb: 0.5
  disk_size_gb: 10

automatic_scaling:
  min_num_instances: 1
  max_num_instances: 5

Cost Warning: Flexible always runs at least 1 instance (~$30-40/month minimum).

Cloud SQL Connection

Standard Environment (Unix Socket)

App Engine Standard connects to Cloud SQL via Unix sockets, not TCP/IP.

# settings.py
import os

if os.getenv('GAE_APPLICATION'):
    # Production: Cloud SQL via Unix socket
    DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.postgresql',
            'NAME': os.environ['DB_NAME'],
            'USER': os.environ['DB_USER'],
            'PASSWORD': os.environ['DB_PASSWORD'],
            'HOST': f"/cloudsql/{os.environ['CLOUD_SQL_CONNECTION_NAME']}",
            'PORT': '',  # Empty for Unix socket
        }
    }
else:
    # Local development: Cloud SQL Proxy or local DB
    DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.postgresql',
            'NAME': os.environ.get('DB_NAME', 'localdb'),
            'USER': os.environ.get('DB_USER', 'postgres'),
            'PASSWORD': os.environ.get('DB_PASSWORD', ''),
            'HOST': '127.0.0.1',
            'PORT': '5432',
        }
    }

# app.yaml
env_variables:
  DB_NAME: "mydb"
  DB_USER: "myuser"
  CLOUD_SQL_CONNECTION_NAME: "project:region:instance"

# CRITICAL: Beta settings for Cloud SQL socket
beta_settings:
  cloud_sql_instances: "project:region:instance"

CRITICAL: The beta_settings.cloud_sql_instances enables the Unix socket. Without it, connection fails.

Local Development with Cloud SQL Proxy

# Download and run Cloud SQL Proxy
cloud-sql-proxy PROJECT:REGION:INSTANCE --port=5432

# Or use Docker
docker run -p 5432:5432 \
  gcr.io/cloud-sql-connectors/cloud-sql-proxy:2.8.0 \
  PROJECT:REGION:INSTANCE

Static Files with Cloud Storage

Option 1: App Engine Static Handlers (Simple)

# app.yaml
handlers:
  - url: /static
    static_dir: staticfiles/
    secure: always
    expiration: "1d"

# Collect static files before deploy
python manage.py collectstatic --noinput
gcloud app deploy

Limitation: Files bundled with deploy, limited to 32MB per file.

Option 2: Cloud Storage (Recommended for Production)

# settings.py
from google.cloud import storage

GS_BUCKET_NAME = os.environ.get('GS_BUCKET_NAME')
STATICFILES_STORAGE = 'storages.backends.gcloud.GoogleCloudStorage'
DEFAULT_FILE_STORAGE = 'storages.backends.gcloud.GoogleCloudStorage'

# Or with django-storages
STORAGES = {
    "default": {
        "BACKEND": "storages.backends.gcloud.GoogleCloudStorage",
        "OPTIONS": {
            "bucket_name": GS_BUCKET_NAME,
            "location": "media",
        },
    },
    "staticfiles": {
        "BACKEND": "storages.backends.gcloud.GoogleCloudStorage",
        "OPTIONS": {
            "bucket_name": GS_BUCKET_NAME,
            "location": "static",
        },
    },
}

# Install django-storages
pip install django-storages[google]

# Create bucket with public access for static files
gsutil mb -l us-central1 gs://YOUR_BUCKET_NAME
gsutil iam ch allUsers:objectViewer gs://YOUR_BUCKET_NAME

Environment Variables and Secrets

Simple: app.yaml env_variables

# app.yaml - NOT for secrets!
env_variables:
  DJANGO_SETTINGS_MODULE: "myproject.settings.production"