为什么 VCAP_SERVICES 为空？答案

【问题标题】：Why is VCAP_SERVICES null?为什么 VCAP_SERVICES 为空？
【发布时间】：2012-08-31 03:14:30
【问题描述】：

我想在我的应用启动期间读取 VCAP_SERVICES 以连接到我的 mongodb 服务，但它为空？

barry-alexanders-MacBook-Pro:~ barryalexander$ vmc create-service mongodb mongodb-relcal RelCal
Creating Service: OK
Binding Service [mongodb-relcal]: OK
Stopping Application 'RelCal': OK
Staging Application 'RelCal': OK                                                
Starting Application 'RelCal': OK                                               

barry-alexanders-MacBook-Pro:~ barryalexander$ vmc apps

+-------------+----+---------+-------------------------+----------------+
| Application | #  | Health  | URLS                    | Services       |
+-------------+----+---------+-------------------------+----------------+
| RelCal      | 1  | RUNNING | relcal.cloudfoundry.com | mongodb-relcal |
| barry       | 1  | STOPPED | barry.cloudfoundry.com  |                |
+-------------+----+---------+-------------------------+----------------+

barry-alexanders-MacBook-Pro:~ barryalexander$ vmc env RelCal
No Environment Variables

【问题讨论】：

标签： mongodb cloud-foundry

【解决方案1】：

使用 vmc 'env' 命令时不会显示 VCAP_SERVICES。但是我们可以通过推送这个简单的节点应用程序看到

var http = require('http');
var util = require('util');

http.createServer(function (req, res) {
  res.writeHead(200, {'Content-Type': 'text/plain'});
  res.write(util.inspect(process.env.VCAP_SERVICES));
  res.write("\n\n************\n\n");
  res.end(util.inspect(req.headers));

}).listen(3000);

输出显示 VCAP_SERVICES 环境变量，然后是请求的标头，输出如下所示；

'{"mongodb-2.0":[{"name":"mongo-test","label":"mongodb-2.0","plan":"free","tags":["mongodb","mongodb-1.8","nosql","document"],"credentials":{"hostname":"172.30.48.70","host":"172.30.48.70","port":25137,"username":"7ad80054-bb70-49fa-9aae-6ff5c1b458fc","password":"491bcfe9-e441-4caf-8422-00a81dbf727b","name":"4b354e7e-c39d-4053-89e1-7195b1360fd9","db":"db","url":"mongodb://7ad80054-bb70-49fa-9aae-6ff5c1b458fc:491bcfe9-e441-4caf-8422-00a81dbf727b@172.30.48.70:25137/db"}}]}'

************

{ host: 'node-headers.cloudfoundry.com',
  'x-forwarded-for': '80.175.199.28, 172.30.8.253',
  connection: 'close',
  'user-agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_4) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.82 Safari/537.1',
  accept: 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
  'accept-language': 'en-US,en;q=0.8',
  'accept-charset': 'ISO-8859-1,utf-8;q=0.7,*;q=0.3',
  'x-cluster-client-ip': '80.175.199.28',
  cookie: '__qca=P0-351832036-1339515989739; s_nr=1344955391423; __utma=207604417.1698837494.1342027762.1345020276.1345215879.7; __utmc=207604417; __utmz=207604417.1342027762.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none); s_cc=true; s_sq=%5B%5BB%5D%5D',
  'accept-encoding': 'gzip,deflate,sdch' }

如果您希望将其用作参考，您可以在http://node-headers.cloudfoundry.com 看到此应用程序的运行情况。

【讨论】：