CloudFoundry虚拟机实例配置DNS

使用Bosh成功部署CloudFoundry后，在OpenStack上启了一个实例作为DNS服务器专用，配置域名mycloud.com解析到CF API接口的IP：10.68.19.134，然后使用CF客户端命令行工具，发现无法登陆CF平台，执行命令及报错如下：

root@bosh-cli:~/bosh-workspace/deployments# cf login admin -t
target: http://api.mycloud.com

>>>
REQUEST: GET http://api.mycloud.com/info
REQUEST_HEADERS:
  Accept : application/json
  Content-Length : 0
RESPONSE: [200]
RESPONSE_HEADERS:
  content-length : 250
  content-type : application/json;charset=utf-8
  date : Mon, 08 Jul 2013 07:48:27 GMT
  server : nginx
  x-content-type-options : nosniff
  x-vcap-request-id : 65130b0b-48b1-42ee-b05b-a844e6dd54f2
RESPONSE_BODY:
{
  "name": "vcap",
  "build": "2222",
  "support": "http://support.cloudfoundry.com",
  "version": 2,
  "description": "Cloud Foundry sponsored by Pivotal",
  "authorization_endpoint": "http://login.mycloud.com",
  "token_endpoint": "http://uaa.mycloud.com",
  "allow_debug": true
}
<<<
Password> ********

Authenticating--->
request: post http://login.mycloud.com/oauth/token
headers: {"content-type"=>"application/x-www-form-urlencoded;charset=utf-8", "accept"=>"application/json;charset=utf-8", "authorization"=>"Basic Y2Y6"}
body: grant_type=password&username=admin&password=c1oudc0w
.  <---
response: 200
headers: {"cache-control"=>"no-cache, no-store, no-cache, no-store, max-age=0", "content-language"=>"en-US", "content-type"=>"application/json;charset=UTF-8", "date"=>"Mon, 08 Jul 2013 07:48:40 GMT", "expires"=>"Thu, 01 Jan 1970 00:00:00 GMT, Thu, 01 Jan 1970 00:00:00 GMT", "pragma"=>"no-cache, no-cache", "server"=>"Apache-Coyote/1.1", "transfer-encoding"=>"chunked"}
body: {"timestamp":"2013-06-12T22:32:57-0700","app":{"artifact":"cloudfoundry-login-server","description":"Cloud Foundry Login App","name":"Cloud Foundry Login","version":"1.2.3"},"error":{"error":"rest_client_error","error_description":"I/O error: uaa.mycloud.com; nested exception is java.net.UnknownHostException: uaa.mycloud.com"},"commit_id":"0f774e2","prompts":{"username":["text","Email"],"password":["password","Password"]}}                              ... FAILED

注意其中错误信息： nested exception is java.net.UnknownHostException: uaa.mycloud.com

分析应该是DNS解析有问题导致，但是执行nslookup命令，查看uaa.mycloud.com却是正常解析到10.68.19.134

再分析，uaa的验证行为是有CF的controller_ng组件发起，通过uaa组件接口进行验证，直接登录到controller_ng组件所在的虚拟机实例上查看DNS解析是否正常，结果果然是无法正常解析

再分析，之前的DNS只在CF客户端所在的机器上进行配置，故其他虚拟机之间进行交互时无法正常解析

尝试修改各虚拟机实例的DNS配置信息，却发现修改后无效，因为采用BOSH进行部署，DNS分为多层：

CF组件实例 ===>> Bosh PowerDNS实例 ===>> Micro Bosh实例 ===>> 虚拟机所在物理机 ===>> 公共DNS服务器

解决办法：

1、停用虚拟机DNS服务器

2、在某一台物理机上配置DNS服务器

3、将每台物理机的DNS配置指向物理DNS服务器

如此，所有的虚拟机的DNS都能通过物理DNS服务器解析，再次尝试CF客户端的登陆等操作，完全正常！