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Docker Basics

All applications on Vapor Cloud run in a Docker container. This gives full flexibility over what is installed for the specific applications.

Docker files in Vapor Cloud 2 should be located in the root directory (Same place as your Package.swift file)

Naming

The Dockerfile need to be named after a specific naming scheme.

The name should be <replicaName>.Dockerfile

For example:

Replica name Dockerfile name
web (default) web.Dockerfile
queue queue.Dockerfile

Testing Locally

You can use Docker or Docker Compose to test your application locally.

Note

You may experience differences between local and deployed results.

Manual Docker

You can build and run your Docker containers manually using docker build and docker run.

docker build -t my-app -f web.Dockerfile

Then run your application with the following command:

docker run --rm -it -p 8080:80 my-app
And test it by visiting http://127.0.0.1:8080.

Docker Compose

You can also use Docker Compose to manage your local test images and containers by creating a docker-compose.yml in the root of your project.

version: '3'
services:
  web:
    ports:
     - 8080:80
    build:
      context: .
      dockerfile: web.Dockerfile

Once saved, you can use the following command to boot your project for testing.

docker-compose up --build web

The --build flag will ensure the image is rebuilt with each run.

Port Settings

Applications inside the container need to listen on port 80. If it listens on another port, the application won't work.

Note

The Docker EXPOSE feature is not supported, and will be ignored.