nodejs-less-server

NodeJs webapp to provide a LESS compiler as a service. By default it runs on 3000 port and accepts compilation requests on / by POST.

Usage

POST request parameters:

• less - LESS source to compile
• url - base URL for @import includes (optional)
• compress - 'true' or 'false', compress the output (optional)

Example querying service from command-line:

curl -v --form "less=@sample.less"  --form "url=http://example.com/some/path/" http://localhost:3000

In case of error, service returns HTTP error 400 with error description in the body:

Column=1
Line=6
Filename=__input__.less
Type=ParseError
Message=Unrecognised input
5 @var: 123
6 .test {
  ^

Server settings

To run on 80 port instead of default 3000 use PORT environment variable:

PORT=80 node server.js

Installation

Below is the complete installation guide for Ubuntu Linux

Installing Node.js

Update the apt-get package lists and install Node.js build dependencies:

sudo apt-get update
sudo apt-get install -y build-essential openssl libssl-dev pkg-config

Download the latest node.js source package from http://nodejs.org/download/ and decompress it:

cd ~
wget http://nodejs.org/dist/v0.12.0/node-v0.12.0.tar.gz
tar xzf node-v0.12.0.tar.gz
cd node-v0.12.0

Then build and install it:

./configure
make
sudo make install

Running node server on port number below 1024 without root

This step is optional. In order to be able to run the application on 80 port run the following commands:

sudo apt-get install libcap2-bin
sudo setcap cap_net_bind_service=+ep /usr/local/bin/node

Installing PM2

PM2 is a production process manager for Node.js applications. Install it using NPM:

sudo npm install pm2 -g

Creating unpriviledged user to run the server

We're going to create user called node:

sudo useradd -s /bin/bash -m -d /home/node -c "nodejs user” node
sudo passwd node
sudo usermod -aG sudo

Installing application

Login as node user:

sudo -iu node

Then clone this repo and install dependencies of the application:

cd ~
git clone https://github.com/Kademi/nodejs-less-server.git
cd nodejs-less-server
npm install

Now the application is installed and can be run within a current terminal session using node server.js command (this should only be used for debugging purposes).

To install the application as a daemon using previously installed PM2 package, type in the following (this will also start the app):

PORT=80 pm2 start server.js -n nodejs-less-server

Then create a system startup script for PM2, so it will start when the system boots:

sudo env PATH=$PATH:/usr/local/bin pm2 startup -u node

Notes on PM2

PM2 will automatically restart the application if it crashes.

To see status of running applications within it, type pm2 list. Once the aplication added to PM2 via pm2 start it could be stopped by pm2 stop <id> or restarted by pm2 restart <id> where <id> is a numeric id of the application or its name (in our case the name is nodejs-less-server).

PM2 also takes care about logs. They are collected to ~/.pm2/logs/ directory by default. To display real-time logs of the application, type pm2 logs nodejs-less-server. Use pm2 flush to empty all log files.