Containerize a Node.js application
Prerequisites
- You have installed the latest version of Docker Desktop.
- You have a git client. The examples in this section use a command-line based git client, but you can use any client.
Overview
This section walks you through containerizing and running a Node.js application.
Get the sample application
Clone the sample application to use with this guide. Open a terminal, change directory to a directory that you want to work in, and run the following command to clone the repository:
$ git clone https://github.com/docker/docker-nodejs-sample
Initialize Docker assets
Now that you have an application, you can use docker init
to create the
necessary Docker assets to containerize your application. Inside the
docker-nodejs-sample
directory, run the docker init
command in a terminal.
docker init
provides some default configuration, but you'll need to answer a
few questions about your application. Refer to the following example to answer
the prompts from docker init
and use the same answers for your prompts.
$ docker init
Welcome to the Docker Init CLI!
This utility will walk you through creating the following files with sensible defaults for your project:
- .dockerignore
- Dockerfile
- compose.yaml
- README.Docker.md
Let's get started!
? What application platform does your project use? Node
? What version of Node do you want to use? 18.0.0
? Which package manager do you want to use? npm
? What command do you want to use to start the app: node src/index.js
? What port does your server listen on? 3000
You should now have the following contents in your docker-nodejs-sample
directory.
├── docker-nodejs-sample/
│ ├── spec/
│ ├── src/
│ ├── .dockerignore
│ ├── .gitignore
│ ├── compose.yaml
│ ├── Dockerfile
│ ├── package-lock.json
│ ├── package.json
│ ├── README.Docker.md
│ └── README.md
To learn more about the files that docker init
added, see the following:
Run the application
Inside the docker-nodejs-sample
directory, run the following command in a
terminal.
$ docker compose up --build
Open a browser and view the application at http://localhost:3000. You should see a simple todo application.
In the terminal, press ctrl
+c
to stop the application.
Run the application in the background
You can run the application detached from the terminal by adding the -d
option. Inside the docker-nodejs-sample
directory, run the following command
in a terminal.
$ docker compose up --build -d
Open a browser and view the application at http://localhost:3000.
You should see a simple todo application.
In the terminal, run the following command to stop the application.
$ docker compose down
For more information about Compose commands, see the Compose CLI reference.
Summary
In this section, you learned how you can containerize and run your Node.js application using Docker.
Related information:
Next steps
In the next section, you'll learn how you can develop your application using containers.