Public | Automated Build

Last pushed: a year ago
Short Description
This is a Digital Garage curated S2I builder image for Node JS
Full Description

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.
Users can choose between RHEL and CentOS based builder images.
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 RHEL based image

     $ s2i build https://github.com/openshift/s2i-nodejs.git --context-dir=0.10/test/test-app/ openshift/nodejs-010-rhel7 nodejs-sample-app
     $ docker run -p 8080:8080 nodejs-sample-app
    
  • For CentOS based image

     $ s2i build https://github.com/openshift/s2i-nodejs.git --context-dir=0.10/test/test-app/ openshift/nodejs-010-centos7 nodejs-sample-app
     $ docker run -p 8080:8080 nodejs-sample-app
    

Accessing the application:

$ curl 127.0.0.1:8080

Repository organization

  • <nodejs-version>

    • Dockerfile

      CentOS based Dockerfile.

    • Dockerfile.rhel7

      RHEL based Dockerfile. In order to perform build or test actions on this
      Dockerfile you need to run the action on a properly subscribed RHEL machine.

    • 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

Application developers can use the following environment variables to configure the runtime behavior of this image:

NAME Description
NODE_ENV NodeJS runtime mode (default: "production")
DEV_MODE When set to "true", nodemon will be used to automatically reload the server while you work (default: "false"). Setting DEV_MODE to "true" will change the NODE_ENV default to "development" (if not explicitly set).
NPM_RUN Select an alternate / custom runtime mode, defined in your package.json file's scripts section (default: npm run "start"). These user-defined run-scripts are unavailable while DEV_MODE is in use.
HTTP_PROXY use an npm proxy during assembly
HTTPS_PROXY use an npm proxy during assembly

One way to define a set of environment variables is to include them as key value pairs in your repo's .s2i/environment file.

Example: DATABASE_USER=sampleUser

NOTE: Define your own "DEV_MODE":

The following package.json example includes a scripts.dev entry. You can define your own custom NPM_RUN scripts in your application's package.json file.

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 OpenShift, you can use oc rsync to copy local files to a remote container running in an OpenShift pod.

Warning:

The default behaviour of the s2i-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.

Docker Pull Command
Owner
thedigitalgarage
Source Repository

Comments (0)