Note: This update is an early-access release. This chapter has not yet been updated to Vapor 4.
Docker is a popular containerization technology that has made a huge impact in the way applications are deployed. Containers are a way of isolating your applications, allowing you to run multiple applications on the same server.
Using a container, instead of a full-fledged virtual machine, allows your containerized applications to share more of the host machine’s resources. In turn, this leaves more resources for your application to use rather than consuming them to support the virtual machine itself.
Docker can run almost anywhere, so it provides a good way to standardize how your application should run, from local testing to production.
Note: If you need a refresher on Docker terminology — concepts such as containers and images — check out our Docker tutorial at https://www.raywenderlich.com/9159-docker-on-macos-getting-started.
This chapter will also show you how to use Docker Compose. Docker Compose is a way to specify a list of different containers that work together as a single unit. These containers share the same virtual network, making it simple for them cooperate with each other.
For example, with Docker Compose, you can spin up both your Vapor app and a PostgreSQL database instance with just one command. They can communicate with each other but are isolated from other instances running on the same host.
Setting up Vapor and PostgreSQL for Development
Begin by setting up a simple development configuration to test your app in a Linux environment. To facilitate debugging any problems that arise, this will be a much simpler configuration than you’ll use in production.
#1 FROM swift:4.2 #2 WORKDIR /app #3 COPY . . #4 RUN swift package clean RUN swift build -c release RUN mkdir /app/bin RUN mv `swift build -c release --show-bin-path` /app/bin EXPOSE 8080 #5 ENTRYPOINT ./bin/release/Run serve --env local \ --hostname 0.0.0.0
# 1 version: '3' # 2 services: # 3 til-app: # 4 depends_on: - postgres # 5 build: . # 6 ports: - "8080:8080" environment: - DATABASE_HOSTNAME=postgres - DATABASE_PORT=5432 # 7 postgres: # 8 image: "postgres" # 9 environment: - POSTGRES_DB=vapor - POSTGRES_USER=vapor - POSTGRES_PASSWORD=password # 10 start_dependencies: image: dadarek/wait-for-dependencies depends_on: - postgres command: postgres:5432
# 1 docker-compose build # 2 docker-compose run --rm start_dependencies # 3 docker-compose up til-app
docker-compose down docker volume prune
Setting up Vapor and PostgreSQL for Production
There are several changes you can make to your Docker configuration to simplify managing your app in a production environment. In this section, you’ll split your app into a “builder” container and a production image. You’ll also configure the PostgreSQL container to save its database in your host’s file system, making your data persist across changes to your app and its configuration.
# 1 FROM swift:4.2 as builder # 2 RUN apt-get -qq update && apt-get -q -y install \ tzdata \ && rm -r /var/lib/apt/lists/* # 3 WORKDIR /app # 4 COPY . . # 5 RUN mkdir -p /build/lib && \ cp -R /usr/lib/swift/linux/*.so /build/lib RUN swift build -c release && \ mv `swift build -c release --show-bin-path` /build/bin # Production image # 6 FROM ubuntu:16.04 # 7 RUN apt-get -qq update && apt-get install -y \ libicu55 libxml2 libbsd0 libcurl3 libatomic1 \ tzdata \ && rm -r /var/lib/apt/lists/* # 8 WORKDIR /app # 9 COPY --from=builder /build/bin/Run . COPY --from=builder /build/lib/* /usr/lib/ # You need the next line if your app serves static resources # from the Public directory COPY --from=builder /app/Public ./Public # You need the next line if your app uses Leaf COPY --from=builder /app/Resources ./Resources # 10 ENTRYPOINT ./Run serve --env production --hostname 0.0.0.0 \ --port 8080
# 1 version: '3' # 2 services: # 3 til-app: # 4 depends_on: - postgres # 5 build: context: . dockerfile: production.Dockerfile # 6 ports: - "8080:8080" environment: - DATABASE_HOSTNAME=postgres - DATABASE_PORT=5432 # 7 postgres: # 8 image: "postgres" # 9 volumes: - ~/postgres-data:/var/lib/postgresql/data # 10 environment: - POSTGRES_DB=vapor - POSTGRES_USER=vapor - POSTGRES_PASSWORD=password # 11 start_dependencies: image: dadarek/wait-for-dependencies depends_on: - postgres command: postgres:5432
docker-compose -f docker-compose.production.yml build docker-compose -f docker-compose.production.yml \ run --rm start_dependencies docker-compose -f docker-compose.production.yml up til-app
Where to go from here?
You’ve seen some basic recipes for how to run your app in a Docker environment. Because Docker is so flexible, these recipes only scratch the surface of the possibilities available to you. For example, you might want to allow your app to save uploaded files in the host’s file system. Or, you might want to configure the app to run behind an nginx proxy server to get secure HTTPS access.