[javascript] How do I configure different environments in Angular.js?

How do you manage configuration variables/constants for different environments?

This could be an example:

My rest API is reachable on localhost:7080/myapi/, but my friend that works on the same code under Git version control has the API deployed on his Tomcat on localhost:8099/hisapi/.

Supposing that we have something like this :

angular
    .module('app', ['ngResource'])

    .constant('API_END_POINT','<local_end_point>')

    .factory('User', function($resource, API_END_POINT) {
        return $resource(API_END_POINT + 'user');
    });

How do I dynamically inject the correct value of the API endpoint, depending on the environment?

In PHP I usually do this kind of stuff with a config.username.xml file, merging the basic configuration file (config.xml) with the local environment configuration file recognised by the name of the user. But I don't know how to manage this kind of thing in JavaScript?

For Gulp users, gulp-ng-constant is also useful combined with gulp-concat, event-stream and yargs.

var concat = require('gulp-concat'),
    es = require('event-stream'),
    gulp = require('gulp'),
    ngConstant = require('gulp-ng-constant'),
    argv = require('yargs').argv;

var enviroment = argv.env || 'development';

gulp.task('config', function () {
  var config = gulp.src('config/' + enviroment + '.json')
    .pipe(ngConstant({name: 'app.config'}));
  var scripts = gulp.src('js/*');
  return es.merge(config, scripts)
    .pipe(concat('app.js'))
    .pipe(gulp.dest('app/dist'))
    .on('error', function() { });
});

In my config folder I have these files:

ls -l config
total 8
-rw-r--r--+ 1 .. ci.json
-rw-r--r--+ 1 .. development.json
-rw-r--r--+ 1 .. production.json

Then you can run gulp config --env development and that will create something like this:

angular.module("app.config", [])
.constant("foo", "bar")
.constant("ngConstant", true);

I also have this spec:

beforeEach(module('app'));

it('loads the config', inject(function(config) {
  expect(config).toBeTruthy();
}));

One cool solution might be separating all environment-specific values into some separate angular module, that all other modules depend on:

angular.module('configuration', [])
       .constant('API_END_POINT','123456')
       .constant('HOST','localhost');

Then your modules that need those entries can declare a dependency on it:

angular.module('services',['configuration'])
       .factory('User',['$resource','API_END_POINT'],function($resource,API_END_POINT){
           return $resource(API_END_POINT + 'user');
       });

Now you could think about further cool stuff:

The module, that contains the configuration can be separated into configuration.js, that will be included at your page.

This script can be easily edited by each of you, as long as you don’t check this separate file into git. But it's easier to not check in the configuration if it is in a separate file. Also, you could branch it locally.

Now, if you have a build-system, like ANT or Maven, your further steps could be implementing some placeholders for the values API_END_POINT, that will be replaced during build-time, with your specific values.

Or you have your configuration_a.js and configuration_b.js and decide at the backend which to include.

If you're using Brunch, the plugin Constangular helps you to manage variables for different environments.

Have you seen this question and its answer?

You can set a globally valid value for you app like this:

app.value('key', 'value');

and then use it in your services. You could move this code to a config.js file and execute it on page load or another convenient moment.

Good question!

One solution could be to continue using your config.xml file, and provide api endpoint information from the backend to your generated html, like this (example in php):

<script type="text/javascript">
angular.module('YourApp').constant('API_END_POINT', '<?php echo $apiEndPointFromBackend; ?>');
</script>

Maybe not a pretty solution, but it would work.

Another solution could be to keep the API_END_POINT constant value as it should be in production, and only modify your hosts-file to point that url to your local api instead.

Or maybe a solution using localStorage for overrides, like this:

.factory('User',['$resource','API_END_POINT'],function($resource,API_END_POINT){
   var myApi = localStorage.get('myLocalApiOverride');
   return $resource((myApi || API_END_POINT) + 'user');
});

We could also do something like this.

(function(){
    'use strict';

    angular.module('app').service('env', function env() {

        var _environments = {
            local: {
                host: 'localhost:3000',
                config: {
                    apiroot: 'http://localhost:3000'
                }
            },
            dev: {
                host: 'dev.com',
                config: {
                    apiroot: 'http://localhost:3000'
                }
            },
            test: {
                host: 'test.com',
                config: {
                    apiroot: 'http://localhost:3000'
                }
            },
            stage: {
                host: 'stage.com',
                config: {
                apiroot: 'staging'
                }
            },
            prod: {
                host: 'production.com',
                config: {
                    apiroot: 'production'
                }
            }
        },
        _environment;

        return {
            getEnvironment: function(){
                var host = window.location.host;
                if(_environment){
                    return _environment;
                }

                for(var environment in _environments){
                    if(typeof _environments[environment].host && _environments[environment].host == host){
                        _environment = environment;
                        return _environment;
                    }
                }

                return null;
            },
            get: function(property){
                return _environments[this.getEnvironment()].config[property];
            }
        }

    });

})();

And in your controller/service, we can inject the dependency and call the get method with property to be accessed.

(function() {
    'use strict';

    angular.module('app').service('apiService', apiService);

    apiService.$inject = ['configurations', '$q', '$http', 'env'];

    function apiService(config, $q, $http, env) {

        var service = {};
        /* **********APIs **************** */
        service.get = function() {
            return $http.get(env.get('apiroot') + '/api/yourservice');
        };

        return service;
    }

})();

$http.get(env.get('apiroot') would return the url based on the host environment.

Very late to the thread, but a technique I've used, pre-Angular, is to take advantage of JSON and the flexibility of JS to dynamically reference collection keys, and use inalienable facts of the environment (host server name, current browser language, etc.) as inputs to selectively discriminate/prefer suffixed key names within a JSON data structure.

This provides not merely deploy-environment context (per OP) but any arbitrary context (such as language) to provide i18n or any other variance required simultaneously, and (ideally) within a single configuration manifest, without duplication, and readably obvious.

IN ABOUT 10 LINES VANILLA JS

Overly-simplified but classic example: An API endpoint base URL in a JSON-formatted properties file that varies per environment where (natch) the host server will also vary:

    ...
    'svcs': {
        'VER': '2.3',
        'API@localhost': 'http://localhost:9090/',
        '[email protected]': 'https://www.uat.productionwebsite.com:9090/res/',
        '[email protected]': 'https://www.productionwebsite.com:9090/api/res/'
    },
    ...

A key to the discrimination function is simply the server hostname in the request.

This, naturally, can be combined with an additional key based on the user's language settings:

    ...
    'app': {
        'NAME': 'Ferry Reservations',
        'NAME@fr': 'Réservations de ferry',
        'NAME@de': 'Fähren Reservierungen'
    },
    ...

The scope of the discrimination/preference can be confined to individual keys (as above) where the "base" key is only overwritten if there's a matching key+suffix for the inputs to the function -- or an entire structure, and that structure itself recursively parsed for matching discrimination/preference suffixes:

    'help': {
        'BLURB': 'This pre-production environment is not supported. Contact Development Team with questions.',
        'PHONE': '808-867-5309',
        'EMAIL': '[email protected]'
    },
    '[email protected]': {
        'BLURB': 'Please contact Customer Service Center',
        'BLURB@fr': 'S\'il vous plaît communiquer avec notre Centre de service à la clientèle',
        'BLURB@de': 'Bitte kontaktieren Sie unseren Kundendienst!!1!',
        'PHONE': '1-800-CUS-TOMR',
        'EMAIL': '[email protected]'
    },

SO, if a visiting user to the production website has German (de) language preference setting, the above configuration would collapse to:

    'help': {
        'BLURB': 'Bitte kontaktieren Sie unseren Kundendienst!!1!',
        'PHONE': '1-800-CUS-TOMR',
        'EMAIL': '[email protected]'
    },

What does such a magical preference/discrimination JSON-rewriting function look like? Not much:

// prefer(object,suffix|[suffixes]) by/par/durch storsoc
// prefer({ a: 'apple', a@env: 'banana', b: 'carrot' },'env') -> { a: 'banana', b: 'carrot' }
function prefer(o,sufs) {
    for (var key in o) {
        if (!o.hasOwnProperty(key)) continue; // skip non-instance props
        if(key.split('@')[1]) { // suffixed!
            // replace root prop with the suffixed prop if among prefs
            if(o[key] && sufs.indexOf(key.split('@')[1]) > -1) o[key.split('@')[0]] = JSON.parse(JSON.stringify(o[key]));

            // and nuke the suffixed prop to tidy up
            delete o[key];

            // continue with root key ...
            key = key.split('@')[0];
        }

        // ... in case it's a collection itself, recurse it!
        if(o[key] && typeof o[key] === 'object') prefer(o[key],sufs);

    };
};

In our implementations, which include Angular and pre-Angular websites, we simply bootstrap the configuration well ahead of other resource calls by placing the JSON within a self-executing JS closure, including the prefer() function, and fed basic properties of hostname and language-code (and accepts any additional arbitrary suffixes you might need):

(function(prefs){ var props = {
    'svcs': {
        'VER': '2.3',
        'API@localhost': 'http://localhost:9090/',
        '[email protected]': 'https://www.uat.productionwebsite.com:9090/res/',
        '[email protected]': 'https://www.productionwebsite.com:9090/api/res/'
    },
    ...
    /* yadda yadda moar JSON und bisque */

    function prefer(o,sufs) {
        // body of prefer function, broken for e.g.
    };

    // convert string and comma-separated-string to array .. and process it
    prefs = [].concat( ( prefs.split ? prefs.split(',') : prefs ) || []);
    prefer(props,prefs);
    window.app_props = JSON.parse(JSON.stringify(props));
})([location.hostname, ((window.navigator.userLanguage || window.navigator.language).split('-')[0])  ] );

A pre-Angular site would now have a collapsed (no @ suffixed keys) window.app_props to refer to.

An Angular site, as a bootstrap/init step, simply copies the dead-dropped props object into $rootScope, and (optionally) destroys it from global/window scope

app.constant('props',angular.copy(window.app_props || {})).run( function ($rootScope,props) { $rootScope.props = props; delete window.app_props;} );

to be subsequently injected into controllers:

app.controller('CtrlApp',function($log,props){ ... } );

or referred to from bindings in views:

<span>{{ props.help.blurb }} {{ props.help.email }}</span>

Caveats? The @ character is not valid JS/JSON variable/key naming, but so far accepted. If that's a deal-breaker, substitute for any convention you like, such as "__" (double underscore) as long as you stick to it.

The technique could be applied server-side, ported to Java or C# but your efficiency/compactness may vary.

Alternately, the function/convention could be part of your front-end compile script, so that the full gory all-environment/all-language JSON is never transmitted over the wire.

UPDATE

We've evolved usage of this technique to allow multiple suffixes to a key, to avoid being forced to use collections (you still can, as deeply as you want), and as well to honor the order of the preferred suffixes.

Example (also see working jsFiddle):

var o = { 'a':'apple', 'a@dev':'apple-dev', 'a@fr':'pomme',
          'b':'banana', 'b@fr':'banane', 'b@dev&fr':'banane-dev',
          'c':{ 'o':'c-dot-oh', 'o@fr':'c-point-oh' }, 'c@dev': { 'o':'c-dot-oh-dev', 'o@fr':'c-point-oh-dev' } };

/*1*/ prefer(o,'dev');        // { a:'apple-dev', b:'banana',     c:{o:'c-dot-oh-dev'}   }
/*2*/ prefer(o,'fr');         // { a:'pomme',     b:'banane',     c:{o:'c-point-oh'}     }
/*3*/ prefer(o,'dev,fr');     // { a:'apple-dev', b:'banane-dev', c:{o:'c-point-oh-dev'} }
/*4*/ prefer(o,['fr','dev']); // { a:'pomme',     b:'banane-dev', c:{o:'c-point-oh-dev'} }
/*5*/ prefer(o);              // { a:'apple',     b:'banana',     c:{o:'c-dot-oh'}       }

1/2 (basic usage) prefers '@dev' keys, discards all other suffixed keys

3 prefers '@dev' over '@fr', prefers '@dev&fr' over all others

4 (same as 3 but prefers '@fr' over '@dev')

5 no preferred suffixes, drops ALL suffixed properties

It accomplishes this by scoring each suffixed property and promoting the value of a suffixed property to the non-suffixed property when iterating over the properties and finding a higher-scored suffix.

Some efficiencies in this version, including removing dependence on JSON to deep-copy, and only recursing into objects that survive the scoring round at their depth:

function prefer(obj,suf) {
    function pr(o,s) {
        for (var p in o) {
            if (!o.hasOwnProperty(p) || !p.split('@')[1] || p.split('@@')[1] ) continue; // ignore: proto-prop OR not-suffixed OR temp prop score
            var b = p.split('@')[0]; // base prop name
            if(!!!o['@@'+b]) o['@@'+b] = 0; // +score placeholder
            var ps = p.split('@')[1].split('&'); // array of property suffixes
            var sc = 0; var v = 0; // reset (running)score and value
            while(ps.length) {
                // suffix value: index(of found suffix in prefs)^10
                v = Math.floor(Math.pow(10,s.indexOf(ps.pop())));
                if(!v) { sc = 0; break; } // found suf NOT in prefs, zero score (delete later)
                sc += v;
            }
            if(sc > o['@@'+b]) { o['@@'+b] = sc; o[b] = o[p]; } // hi-score! promote to base prop
            delete o[p];
        }
        for (var p in o) if(p.split('@@')[1]) delete o[p]; // remove scores
        for (var p in o) if(typeof o[p] === 'object') pr(o[p],s); // recurse surviving objs
    }
    if( typeof obj !== 'object' ) return; // validate
    suf = ( (suf || suf === 0 ) && ( suf.length || suf === parseFloat(suf) ) ? suf.toString().split(',') : []); // array|string|number|comma-separated-string -> array-of-strings
    pr(obj,suf.reverse());
}

To achieve that, I suggest you to use AngularJS Environment Plugin: https://www.npmjs.com/package/angular-environment

Here's an example:

angular.module('yourApp', ['environment']).
config(function(envServiceProvider) {
    // set the domains and variables for each environment 
    envServiceProvider.config({
        domains: {
            development: ['localhost', 'dev.local'],
            production: ['acme.com', 'acme.net', 'acme.org']
            // anotherStage: ['domain1', 'domain2'], 
            // anotherStage: ['domain1', 'domain2'] 
        },
        vars: {
            development: {
                apiUrl: '//localhost/api',
                staticUrl: '//localhost/static'
                // antoherCustomVar: 'lorem', 
                // antoherCustomVar: 'ipsum' 
            },
            production: {
                apiUrl: '//api.acme.com/v2',
                staticUrl: '//static.acme.com'
                // antoherCustomVar: 'lorem', 
                // antoherCustomVar: 'ipsum' 
            }
            // anotherStage: { 
            //  customVar: 'lorem', 
            //  customVar: 'ipsum' 
            // } 
        }
    });

    // run the environment check, so the comprobation is made 
    // before controllers and services are built 
    envServiceProvider.check();
});

And then, you can call the variables from your controllers such as this:

envService.read('apiUrl');

Hope it helps.

You could use lvh.me:9000 to access your AngularJS app, (lvh.me just points to 127.0.0.1) and then specify a different endpoint if lvh.me is the host:

app.service("Configuration", function() {
  if (window.location.host.match(/lvh\.me/)) {
    return this.API = 'http://localhost\\:7080/myapi/';
  } else {
    return this.API = 'http://localhost\\:8099/hisapi/';
  }
});

And then inject the Configuration service and use Configuration.API wherever you need to access the API:

$resource(Configuration.API + '/endpoint/:id', {
  id: '@id'
});

A tad clunky, but works fine for me, albeit in a slightly different situation (API endpoints differ in production and development).