Dockerize a Platformatic App

This guide explains how to create a new Platformatic DB app, which connects to a PostgreSQL database.

We will then create a docker-compose.yml file that will run both services in separate containers

Generate a Platformatic DB App

To start the Platformatic creator wizard, run the appropriate command for your package manager in your terminal:

npm

npm create platformatic@latest

yarn

yarn create platformatic

pnpm

pnpm create platformatic@latest

This interactive command-line tool will guide you through setting up a new Platformatic project. For this guide, please choose the following options:

- What kind of project do you want to create?   => Application
- Where would you like to create your project?  => quick-start
- Which kind of project do you want to create?  => @platformatic/db
- What is the name of the service?              => (generated-randomly), e.g. legal-soup
- What is the connection string?                => sqlite://./db.sqlite
- Do you want to create default migrations?     => Yes
- Do you want to create another service?        => No
- Do you want to use TypeScript?                => No
- What port do you want to use?                 => 3042
- Do you want to init the git repository?       => No

After completing the wizard, your Platformatic application will be ready in the quick-start folder. This includes example migration files, plugin scripts, routes, and tests within your service directory.

note

If the wizard does not handle dependency installation, ensure to run npm/yarn/pnpm install command manually:

Create Docker image for the Platformatic DB App

In this step you are going to create some files into the root project directory

• .dockerignore - This file tells Docker to ignore some files when copying the directory into the image filesystem

node_modules
.env*

• start.sh - This is our entrypoint. We will run migrations then start platformatic

#!/bin/sh

echo "Running migrations..." && \
npx platformatic db migrations apply && \
echo "Starting Platformatic App..." && \
npm start

info

Make sure you make this file executable with the command chmod +x start.sh

• Dockerfile - This is the file Docker uses to create the image

FROM node:18-alpine
WORKDIR /usr/src/app
COPY . .
RUN npm install
COPY . .
EXPOSE 3042
CMD [ "./start.sh" ]

At this point you can build your Docker image with the command

$ docker build -t platformatic-app .

Create Docker Compose config file

docker-compose.yml is the configuration file for docker-compose which will spin up containers for both PostgresSQL and our Platformatic App

version: "3.3"
services:
  postgresql:
    ports:
      - "5433:5432"
    image: "postgres:15-alpine"
    environment:
      - POSTGRES_PASSWORD=postgres
  platformatic:
    ports:
      - "3042:3042"
    image: 'platformatic-app:latest'
    depends_on:
      - postgresql
    links:
      - postgresql
    environment:
      PLT_SERVER_HOSTNAME: ${PLT_SERVER_HOSTNAME}
      PORT: ${PORT}
      PLT_SERVER_LOGGER_LEVEL: ${PLT_SERVER_LOGGER_LEVEL}
      DATABASE_URL: postgres://postgres:postgres@postgresql:5432/postgres

A couple of things to notice:

• The Platformatic app is started only once the database container is up and running (depends_on).
• The Platformatic app is linked with postgresql service. Meaning that inside its container ping postgresql will be resolved with the internal ip of the database container.
• The environment is taken directly from the .env file created by the wizard

You can now run your containers with

$ docker-compose up # (-d if you want to send them in the background)

Everything should start smoothly, and you can access your app pointing your browser to http://0.0.0.0:3042

To stop the app you can either press CTRL-C if you are running them in the foreground, or, if you used the -d flag, run

$ docker-compose down