Merge branch 'feature/document-env-vars' into develop

Author: dani8art

docs/README.md

@@ -27,7 +27,7 @@ This method receives a URI of a file and builds, (re)creates, starts, and attach
   **file** | `string` | **Required.** The file where the service is described. 
   **options** | `[string]` | **Optional.** Docker compose up commad [options](https://docs.docker.com/compose/reference/up/).
 
-#### Example
+#### Examples
 
 ```javascript
 var dcManager = require('docker-composer-manager');
@@ -40,6 +40,24 @@ dcManager.dockerComposeUp(file).then(out => {
 });
 ```
 
+For passing environment variables to the `docker-compose` command, It is used the `process.env` global variable as follow:
+
+```javascript
+var dcManager = require('docker-composer-manager');
+var file = __dirname + '/docker-compose.yaml';
+
+process.env.MONGO_VERSION = '3.0.15';
+
+dcManager.dockerComposeUp(file).then(() => {
+    return dcManager.dockerExec('withenvironment_mongo_1', ['mongo', '--version']);
+}).then((out) => {
+    return Promise.resolve(expect(out.indexOf('3.0.15')).to.not.be.equal(-1));
+}).then(() => {
+    return dcManager.dockerComposeDown(file);
+}).then(() => done()).catch(err => done(err));
+```
+
+
 ### DockerComposeDown 
 
 This method receives a URI of a file and stops containers, removes containers, networks, volumes, and images created by [dockerComposeUp](#dockercomposeup).

src/docker-compose-manager.js

@@ -184,7 +184,8 @@ function dockerExec(container, exec_command, options) {
 
 function dockerInspectIPAddressOfContainer(container, options) {
     return new Promise((resolve, reject) => {
-        options = options ? options : [];
+        options = options ? options : {};
+        if (!options.network) options.network = 'bridge';
         var command = 'docker';
         var arg = ['inspect', '--format', "'{{.NetworkSettings.Networks." + options.network + ".IPAddress}}'", container];