thedigitalgarage/s2i-nodejs repository overview

⁠Digital Garage NodeJS Docker image

This repository contains the source for building various versions of the Node.JS application as a reproducible Docker image using source-to-image⁠. The resulting image can be run using Docker⁠.

⁠Usage

To build a simple nodejs-sample-app⁠ application using standalone STI⁠ and then run the resulting image with Docker⁠ execute:

• For CentOS based image

  $ s2i build https://github.com/thedigitalgarage/s2i-nodejs.git --context-dir=0.10/test/test-app/ openshift/s2i-nodejs:0.10 nodejs-sample-app
  $ docker run -p 8080:8080 nodejs-sample-app
  

  Copy

Accessing the application:

$ curl 127.0.0.1:8080

⁠Repository organization

• <nodejs-version>

  • Dockerfile

    CentOS based Dockerfile.

  • s2i/bin/

    This folder contains scripts that are run by STI⁠:

    • assemble

      Used to install the sources into the location where the application will be run and prepare the application for deployment (eg. installing modules using npm, etc.)

    • run

      This script is responsible for running the application, by using the application web server.

    • usage*

      This script prints the usage of this image.

  • contrib/

    This folder contains a file with commonly used modules.

  • test/

    This folder contains the S2I⁠ test framework with simple Node.JS echo server.

    • test-app/

      A simple Node.JS echo server used for testing purposes by the S2I⁠ test framework.

    • run

      This script runs the S2I⁠ test framework.

⁠Environment variables

To set environment variables, you can place them as a key value pair into a .sti/environment file inside your source code repository.

Example: DATABASE_USER=sampleUser

Setting the HTTP_PROXY or HTTPS_PROXY environment variable will set the appropriate npm proxy configuration during assembly.

⁠Development Mode

This image supports development mode. This mode can be switched on and off with the environment variable DEV_MODE. DEV_MODE can either be set to true or false. Development mode supports two features:

• Hot Deploy
• Debugging

The debug port can be speicifed with the environment variable DEBUG_PORT. DEBUG_PORT is only valid if DEV_MODE=true.

A simple example command for running the docker container in production mode is:

docker run --env DEV_MODE=true my-image-id

To run the container in development mode with a debug port of 5454, run:

$ docker run --env DEV_MODE=true DEBUG_PORT=5454 my-image-id

To run the container in production mode, run:

$ docker run --env DEV_MODE=false my-image-id

By default, DEV_MODE is set to false, and DEBUG_PORT is set to 5858, however the DEBUG_PORT is only relevant if DEV_MODE=true.

⁠Hot deploy

As part of development mode, this image supports hot deploy. If development mode is enabled, any souce code that is changed in the running container will be immediately reflected in the running nodejs application.

⁠Using Docker's exec

To change your source code in a running container, use Docker's exec⁠ command:

$ docker exec -it <CONTAINER_ID> /bin/bash

After you Docker exec⁠ into the running container, your current directory is set to /opt/app-root/src, where the source code for your application is located.

⁠Using OpenShift's rsync

If you have deployed the container to Digital Garage, you can use oc rsync⁠ to copy local files to a remote container running in a Digital Garage pod.

⁠Warning:

The default behaviour of the sti-nodejs docker image is to run the Node.js application using the command npm start. This runs the start script in the package.json file. In developer mode, the application is run using the command nodemon. The default behaviour of nodemon is to look for the main attribute in the package.json file, and execute that script. If the main attribute doesn't appear in the package.json file, it executes the start script. So, in order to achieve some sort of uniform functionality between production and development modes, the user should remove the main attribute.

Below is an example package.json file with the main attribute and start script marked appropriately:

{
    "name": "node-echo",
    "version": "0.0.1",
    "description": "node-echo",
    "main": "example.js", <--- main attribute
    "dependencies": {
    },
    "devDependencies": {
        "nodemon": "*"
    },
    "engine": {
        "node": "*",
        "npm": "*"
    },
    "scripts": {
        "dev": "nodemon --ignore node_modules/ server.js",
        "start": "node server.js" <-- start script
    },
    "keywords": [
        "Echo"
    ],
    "license": "",
}

⁠Note:

oc rsync is only available in versions 3.1+ of OpenShift.