Welcome to the App Engine flexible environment. App Engine allows developers to focus on doing what they do best, writing code. Based on Google Compute Engine, the App Engine flexible environment automatically scales your app up and down while balancing the load. Microservices, authorization, SQL and NoSQL databases, traffic splitting, logging, versioning, security scanning, and content delivery networks are all supported natively. In addition, the App Engine flexible environment allows you to customize your runtime and even the operating system of your virtual machine using Dockerfiles.
Runtimes - The flexible environment includes native support for Java 8 / Servlet 3.1 / Jetty 9, Python 2.7 and Python 3.5, Node.js, Ruby, PHP, and Go. Developers can customize these runtimes or provide their own runtime by supplying a custom Docker image or Dockerfile from the open source community.
Infrastructure Customization - Because VM instances in the flexible environment are Google Compute Engine virtual machines, you can take advantage of custom libraries, use SSH for debugging, and deploy your own Docker containers.
Performance - Take advantage of a wide array of CPU and memory configurations. You can specify how much CPU and memory each instance of your application needs and the flexible environment will provision the necessary infrastructure for you.
App Engine manages your virtual machines, ensuring that:
- Instances are health-checked, healed as necessary, and co-located with other services within the project.
- Critical, backwards compatible updates are automatically applied to the underlying operating system.
- VM instances are automatically located by geographical region according to the settings in your project. Google's management services ensures that all of a project's VM instances are co-located for optimal performance.
- VM instances are restarted on a weekly basis. During restarts Google's management services will apply any necessary operating system and security updates.
- You always have root access to Compute Engine VM instances. SSH access to VM instances in the flexible environment is disabled by default. If you choose, you can enable root access to your app's VM instances.