1
0
Fork 0
mirror of https://github.com/moby/moby.git synced 2022-11-09 12:21:53 -05:00
moby--moby/docs/sources/examples/nodejs_web_app.rst
zqh 853c5e258f Update nodejs_web_app.rst
the address of epel rpm has change to http://dl.fedoraproject....
2014-03-16 01:07:22 +08:00

239 lines
6.1 KiB
ReStructuredText
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

:title: Running a Node.js app on CentOS
:description: Installing and running a Node.js app on CentOS
:keywords: docker, example, package installation, node, centos
.. _nodejs_web_app:
Node.js Web App
===============
.. include:: example_header.inc
The goal of this example is to show you how you can build your own
Docker images from a parent image using a ``Dockerfile`` . We will do
that by making a simple Node.js hello world web application running on
CentOS. You can get the full source code at
https://github.com/gasi/docker-node-hello.
Create Node.js app
++++++++++++++++++
First, create a ``package.json`` file that describes your app and its
dependencies:
.. code-block:: json
{
"name": "docker-centos-hello",
"private": true,
"version": "0.0.1",
"description": "Node.js Hello World app on CentOS using docker",
"author": "Daniel Gasienica <daniel@gasienica.ch>",
"dependencies": {
"express": "3.2.4"
}
}
Then, create an ``index.js`` file that defines a web app using the
`Express.js <http://expressjs.com/>`_ framework:
.. code-block:: javascript
var express = require('express');
// Constants
var PORT = 8080;
// App
var app = express();
app.get('/', function (req, res) {
res.send('Hello World\n');
});
app.listen(PORT)
console.log('Running on http://localhost:' + PORT);
In the next steps, well look at how you can run this app inside a CentOS
container using Docker. First, youll need to build a Docker image of your app.
Creating a ``Dockerfile``
+++++++++++++++++++++++++
Create an empty file called ``Dockerfile``:
.. code-block:: bash
touch Dockerfile
Open the ``Dockerfile`` in your favorite text editor and add the following line
that defines the version of Docker the image requires to build
(this example uses Docker 0.3.4):
.. code-block:: bash
# DOCKER-VERSION 0.3.4
Next, define the parent image you want to use to build your own image on top of.
Here, well use `CentOS <https://index.docker.io/_/centos/>`_ (tag: ``6.4``)
available on the `Docker index`_:
.. code-block:: bash
FROM centos:6.4
Since were building a Node.js app, youll have to install Node.js as well as
npm on your CentOS image. Node.js is required to run your app and npm to install
your apps dependencies defined in ``package.json``.
To install the right package for CentOS, well use the instructions from the
`Node.js wiki`_:
.. code-block:: bash
# Enable EPEL for Node.js
RUN rpm -Uvh http://dl.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm
# Install Node.js and npm
RUN yum install -y npm
To bundle your apps source code inside the Docker image, use the ``ADD``
instruction:
.. code-block:: bash
# Bundle app source
ADD . /src
Install your app dependencies using the ``npm`` binary:
.. code-block:: bash
# Install app dependencies
RUN cd /src; npm install
Your app binds to port ``8080`` so youll use the ``EXPOSE`` instruction
to have it mapped by the ``docker`` daemon:
.. code-block:: bash
EXPOSE 8080
Last but not least, define the command to run your app using ``CMD``
which defines your runtime, i.e. ``node``, and the path to our app,
i.e. ``src/index.js`` (see the step where we added the source to the
container):
.. code-block:: bash
CMD ["node", "/src/index.js"]
Your ``Dockerfile`` should now look like this:
.. code-block:: bash
# DOCKER-VERSION 0.3.4
FROM centos:6.4
# Enable EPEL for Node.js
RUN rpm -Uvh http://download.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm
# Install Node.js and npm
RUN yum install -y npm
# Bundle app source
ADD . /src
# Install app dependencies
RUN cd /src; npm install
EXPOSE 8080
CMD ["node", "/src/index.js"]
Building your image
+++++++++++++++++++
Go to the directory that has your ``Dockerfile`` and run the following
command to build a Docker image. The ``-t`` flag lets you tag your
image so its easier to find later using the ``docker images``
command:
.. code-block:: bash
sudo docker build -t <your username>/centos-node-hello .
Your image will now be listed by Docker:
.. code-block:: bash
sudo docker images
> # Example
> REPOSITORY TAG ID CREATED
> centos 6.4 539c0211cd76 8 weeks ago
> gasi/centos-node-hello latest d64d3505b0d2 2 hours ago
Run the image
+++++++++++++
Running your image with ``-d`` runs the container in detached mode, leaving the
container running in the background. The ``-p`` flag redirects a public port to a private port in the container. Run the image you previously built:
.. code-block:: bash
sudo docker run -p 49160:8080 -d <your username>/centos-node-hello
Print the output of your app:
.. code-block:: bash
# Get container ID
sudo docker ps
# Print app output
sudo docker logs <container id>
> # Example
> Running on http://localhost:8080
Test
++++
To test your app, get the the port of your app that Docker mapped:
.. code-block:: bash
sudo docker ps
> # Example
> ID IMAGE COMMAND ... PORTS
> ecce33b30ebf gasi/centos-node-hello:latest node /src/index.js 49160->8080
In the example above, Docker mapped the ``8080`` port of the container to
``49160``.
Now you can call your app using ``curl`` (install if needed via:
``sudo apt-get install curl``):
.. code-block:: bash
curl -i localhost:49160
> HTTP/1.1 200 OK
> X-Powered-By: Express
> Content-Type: text/html; charset=utf-8
> Content-Length: 12
> Date: Sun, 02 Jun 2013 03:53:22 GMT
> Connection: keep-alive
>
> Hello World
We hope this tutorial helped you get up and running with Node.js and
CentOS on Docker. You can get the full source code at
https://github.com/gasi/docker-node-hello.
Continue to :ref:`running_redis_service`.
.. _Node.js wiki: https://github.com/joyent/node/wiki/Installing-Node.js-via-package-manager#rhelcentosscientific-linux-6
.. _docker index: https://index.docker.io/