Dockerise a Waku app

Dockerise a Waku app

Bundle your Waku app into a Docker container for portability and easy deployment in various environments.

Prerequisites

Make sure you have Docker and Node.js installed on your machine. We will prepare the image and container in 3 easy steps for reproducible results. Create 3 files in your folder root: Dockerfile, .dockerignore, docker-compose.yml.

Dockerfile

First, let's take a look at Dockerfile where we define the Docker commands to build the app image.

FROM node:18-alpine as builder

WORKDIR /app

# import dependencies
COPY package.json .
COPY package-lock.json .

RUN npm install

# copy assets
COPY . .

RUN npm run build

EXPOSE 8080

CMD ["npm", "run", "start"]

Dockerfile is set up so that it uses Docker's multi-stage build paradigm, in which different layers of the process are cached and reused on subsequent builds if the underlying files have not changed since the previous build. Here's a breakdown of the commands:

1. FROM: use a Node v18 base image to scaffold the build process
2. WORKDIR: set a directory path where all the following commands take place
3. COPY: copy dependency info to the working directory (signified by the dot at the end)
4. RUN: install project dependencies
5. COPY: copy project assets (images, jsx files etc.)
6. RUN: build the app with production settings
7. EXPOSE: declare a port to enable access to the application from the container
8. CMD: start up the app

A health check command can be optionally included at the end of the Dockerfile. An example would be: HEALTHCHECK --interval=30s CMD wget -qO- http://localhost:8080 || exit 1

.dockerignore file

Use an ignore file to avoid copying unnecessary/undesirable files into the image. For example:

/node_modules
.vscode

This way node_modules files will not be copied in the above Dockerfile setup.

docker-compose.yml file

To streamline the build process, create a compose file which will be easily extensible when additional services are needed:

version: '3.8'

services:
  waku-app-frontend:
    build:
      context: .
    image: wakuapp
    environment:
      NODE_ENV: production
    ports:
      - 8080:8080

Specify the name of the service, and within it add the following:

• build context ( cwd ) where the build process should take place
• image name so that the correct image is used to create the container
• environment variables
• port forwarding so the app is accessible on the host machine (e.g. in your browser)

Build the container

Finally, with the blueprints ready, build the container using the following command: docker-compose up -d --build

With this, the app should be accessible from localhost in the browser and the container should be deployable to cloud hosting platforms.