What is Node.js?

Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.

nodejs.org

TLDR

docker run -it --name node bitnami/node

Docker Compose

node:
  image: bitnami/node
  command: node script.js
  volumes:
    - /path/to/node/app:/app

Get this image

The recommended way to get the Bitnami Node.js Docker Image is to pull the prebuilt image from the Docker Hub Registry.

docker pull bitnami/node:latest

To use a specific version, you can pull a versioned tag. You can view the list of available versions in the Docker Hub Registry.

docker pull bitnami/node:[TAG]

If you wish, you can also build the image yourself.

git clone https://github.com/bitnami/bitnami-docker-node.git
cd bitnami-docker-node
docker build -t bitnami/node .

Entering the REPL

By default, running this image will drop you into the Node.js REPL, where you can interactively test and try things out in Node.js.

docker run -it --name node bitnami/node

Further Reading:

• nodejs.org/api/repl.html

Running your Node.js script

The default work directory for the Node.js image is /app. You can mount a folder from your host here that includes your Node.js script, and run it normally using the node command.

docker run -it --name node -v /path/to/node/app:/app bitnami/node \
  node script.js

Running a Node.js app with npm dependencies

If your Node.js app has a package.json defining your app's dependencies and start script, you can install the dependencies before running your app.

docker run --rm -v /path/to/node/app:/app bitnami/node npm install
docker run -it --name node -v /path/to/node/app:/app bitnami/node npm start

or using Docker Compose:

node:
  image: bitnami/node
  command: "sh -c 'npm install && npm start'"

Further Reading:

• package.json documentation
• npm start script

Accessing a Node.js app running a web server

This image exposes port 3000 in the container, so you should ensure that your web server is binding to port 3000, as well as accepting remote connections.

Below is an example of an express.js app listening to remote connections on port 3000:

var express = require('express');
var app = express();

app.get('/', function (req, res) {
  res.send('Hello World!');
});

var server = app.listen(3000, '0.0.0.0', function () {

  var host = server.address().address;
  var port = server.address().port;

  console.log('Example app listening at http://%s:%s', host, port);

});

To access your web server from your host machine you can ask Docker to map a random port on your host to port 3000 inside the container.

docker run -it --name node -P bitnami/node

Run docker port to determine the random port Docker assigned.

$ docker port node
3000/tcp -> 0.0.0.0:32769

You can also manually specify the port you want forwarded from your host to the container.

docker run -it --name node -p 8080:3000 bitnami/node

Access your web server in the browser by navigating to http://localhost:8080.

Linking

If you want to connect to your Node.js web server inside another container, you can use the linking system provided by Docker.

Serving your Node.js app through an nginx frontend

We may want to make our Node.js web server only accessible via an nginx web server. Doing so will allow us to setup more complex configuration, serve static assets using nginx, load balance to different Node.js instances, etc.

Step 1: Create a virtual host

Let's create an nginx virtual host to reverse proxy to our Node.js container. The Bitnami nginx Docker Image ships with some example virtual hosts for connecting to Bitnami runtime images. We will make use of the Node.js example:

server {
    listen 0.0.0.0:80;
    server_name yourapp.com;
    access_log /logs/yourapp_access.log;
    error_log /logs/yourapp_error.log;

    location / {
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header HOST $http_host;
        proxy_set_header X-NginX-Proxy true;

        # proxy_pass http://[your_node_container_link_alias]:3000;
        proxy_pass http://yourapp:3000;
        proxy_redirect off;
    }
}

Notice we've substituted the link alias name yourapp, we will use the same name when creating the link.

Copy the virtual host above, saving the file somewhere on your host. We will mount it as a volume in our nginx container.

Step 2: Run the Node.js image with a specific name

Docker's linking system uses container ids or names to reference containers. We can explicitly specify a name for our Node.js server to make it easier to connect to other containers.

docker run -it --name node -v /path/to/node/app:/app bitnami/node npm start

or using Docker Compose:

node:
  image: bitnami/node
  command: npm start
  volumes:
    - /path/to/node/app:/app

Step 3: Run the nginx image and link it to the Node.js server

Now that we have our Node.js server running, we can create another container that links to it by giving Docker the --link option. This option takes the id or name of the container we want to link it to as well as a hostname to use inside the container, separated by a colon. For example, to have our Node.js server accessible in another container with yourapp as it's hostname we would pass --link node:yourapp to the Docker run command.

docker run -it -v /path/to/vhost.conf:/bitnami/nginx/conf/vhosts/yourapp.conf \
  --link node:yourapp \
  bitnami/nginx

or using Docker Compose:

nginx:
  image: bitnami/nginx
  links:
    - node:yourapp
  volumes:
    - /path/to/vhost.conf:/bintami/nginx/conf/yourapp.conf

We started the nginx server, mounting the virtual host we created in Step 1, and created a link to the Node.js server with the alias yourapp.

Maintenance

Upgrade this image

Bitnami provides up-to-date versions of Node.js, including security patches, soon after they are made upstream. We recommend that you follow these steps to upgrade your container.

Step 1: Get the updated image

docker pull bitnami/node:latest

or if you're using Docker Compose, update the value of the image property to bitnami/node:latest.

Step 2: Remove the currently running container

docker rm -v node

or using Docker Compose:

docker-compose rm -v node

Step 3: Run the new image

Re-create your container from the new image.

docker run --name node bitnami/node:latest

or using Docker Compose:

docker-compose start node

Testing

This image is tested for expected runtime behavior, using the Bats testing framework. You can run the tests on your machine using the bats command.

bats test.sh

Contributing

We'd love for you to contribute to this Docker image. You can request new features by creating an issue, or submit a pull request with your contribution.

Issues

If you encountered a problem running this container, you can file an issue. For us to provide better support, be sure to include the following information in your issue:

• Host OS and version
• Docker version (docker version)
• Output of docker info
• Version of this container (echo $BITNAMI_APP_VERSION inside the container)
• The command you used to run the container, and any relevant output you saw (masking any sensitive information)

License

Copyright 2015 Bitnami

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.