廢話開頭：
之前參考這位同學的博客http://www.cnblogs.com/awy-blog/p/3447176.html，同時綜合OpenStack的ubuntu的官方安裝文檔，在修改了一些小錯誤之后，成功地用三台普通的物理PC機搭了一個OpenStack的環境，各項服務、功能都測試了一遍，感覺還可以。不過后來，由於其中的一台物理機被別人拿走之后，於是乎沒繼續使用測試了，轉而去研究代碼了。
后來，由於某種需求，又要開重新搭建這個環境。沒有夠多的物理機，於是乎開始使用樓下的一台刀片服務器來完了，12核24線程、40多G的大內存，4塊500G的硬盤，夠給力了，跑三個虛擬機來搭OpenStack的環境也綽綽有余了。但是，搭完之后，問題就來了，發現無法向虛機注入密鑰，也就是用ssh密鑰登錄虛機了。這對那些必須需要使用密鑰登錄的鏡像來說還是有很大的不便。
下面開始步入正題：
虛機起來后，查看日志/var/log/nova/nova-api.log ：
2014-03-08 15:36:02.347 16855 INFO nova.metadata.wsgi.server [-] (16855) accepted ('192.168.122.3', 55466) 2014-03-08 15:36:02.349 16855 WARNING nova.api.metadata.handler [-] X-Instance-ID-Signature: ed0c9bbac98384bb1d4f2b0923e33488af7ac2fbbaac0aef6fe2b80257cded79 does not match the expected value: 93008c9f8f5a8ddda5a9fd48fb29b53db2e2ef1c76684ef4f6e5152fc951885d for id: c011b486-3cfd-4e33-8fb8-526abe1e51fb. Request From: 10.50.50.2 2014-03-08 15:36:02.350 16855 INFO nova.api.ec2 [-] 0.1089s 192.168.122.3 GET /2009-04-04/meta-data/public-hostname None:None 403 [Python-httplib2/0.7.2 (gzip)] text/plain text/plain 2014-03-08 15:36:02.350 16855 INFO nova.metadata.wsgi.server [-] 10.50.50.2,192.168.122.3 "GET /2009-04-04/meta-data/public-hostname HTTP/1.1" status: 403len: 176 time: 0.0018518 2014-03-08 15:36:02.865 16855 WARNING nova.api.metadata.handler [-] X-Instance-ID-Signature: ed0c9bbac98384bb1d4f2b0923e33488af7ac2fbbaac0aef6fe2b80257cded79 does not match the expected value: 93008c9f8f5a8ddda5a9fd48fb29b53db2e2ef1c76684ef4f6e5152fc951885d for id: c011b486-3cfd-4e33-8fb8-526abe1e51fb. Request From: 10.50.50.2 2014-03-08 15:36:02.867 16855 INFO nova.api.ec2 [-] 0.1279s 192.168.122.3 GET /2009-04-04/meta-data/placement/availability-zone None:None 403 [Python-httplib2/0.7.2 (gzip)] text/plain text/plain 2014-03-08 15:36:02.868 16855 INFO nova.metadata.wsgi.server [-] 10.50.50.2,192.168.122.3 "GET /2009-04-04/meta-data/placement/availability-zone HTTP/1.1" status: 403len: 176 time: 0.0024281
在dashboard的界面里面，查看虛機的日志中提示錯誤：
checking http://169.254.169.254/2009-04-04/instance-id
failed 1/20: up 10.44. iid had '<html>
<head>
<title>500 Internal Server Error</title>
</head>
<body>
<h1>500 Internal Server Error</h1>
An unknown error has occurred. Please try your request again.<br /><br />
而當我登錄虛擬，查看里面的~/.ssh/authorized_keys里面內容不是要注入的公鑰，正是上面出錯的html頁面代碼！
在虛機中運行curl檢測如下：
$ curl -I http://169.254.169.254/2009-04-04/meta-data/instance-id
HTTP/1.1 500 Internal Server Error
Content-Type: text/html; charset=UTF-8
Content-Length: 0
Date: Sat, 08 Mar 2014 09:45:57 GMT
if resp.status == 200: LOG.debug(str(resp)) return content elif resp.status == 403: msg = _( 'The remote metadata server responded with Forbidden. This' 'response usually occurs when shared secrets do not match.' ) LOG.warn(msg) return webob.exc.HTTPForbidden() elif resp.status == 404: return webob.exc.HTTPNotFound() elif resp.status == 409: return webob.exc.HTTPConflict() elif resp.status == 500: msg = _( 'Remote metadata server experienced an internal server error.' ) LOG.warn(msg) return webob.exc.HTTPInternalServerError(explanation=unicode(msg)) else: raise Exception(_('Unexpected response code: %s') % resp.status)
# shared secret to prevent spoofing. You may select any string for a secret,
# but it must match here and in the configuration used by the Nova Metadata
# Server. NOTE: Nova uses a different key: neutron_metadata_proxy_shared_secret