Zenoss Ganglia ZenPack Fix

My company uses Zenoss to monitor all Linux hosts. And we want to use Ganglia ZenPack to monitor our Hadoop clusters. The ZenPack from this link doesn't work in my Zenoss, community version 3.1.0. A lot of weird things happened when I loaded the egg using "Advance -> Settings -> ZenPacks -> Install ZenPack ...". I also tried the source code of the ZenPack in github, and no luck. Finally I fixed the issue of Ganglia ZenPack and it worked perfectly in Zenoss 3.1.0. I created an ZenPack in Zenoss using "Create ZenPack ...", and used the folders under $ZENHOME/ZenPacks as a skeleton. And copied the files in the ZenPack from github except the skins. I also changed this line, but I don't remember if this is important.

diff ZenPacks/jschroeder/GangliaMonitor/datasources/GangliaMonitorDataSource.py /workplace/ws-zenpacks/ZenPacks.jschroeder.GangliaMonitor/ZenPacks/jschroeder/GangliaMonitor/datasources/GangliaMonitorDataSource.py 
72c72
<             return self.hostname
---
>             return self.host

Because I am a newbie of Zenoss, the following may be useful for you:

• Switch to zenoss sudo su - zenoss
• run zenpack --link --install=/tmp/ZenPacks.jschroeder.GangliaMonitor
• If everything is correct, you should see ZenPack in the web page.

You'd better use command line tool zenpack, it will save you a lot of time if you are new to Zenoss and Python. You probably need to run zopectl restart time to time. From my experience with Zenoss, if your ZenPack works, everything looks perfect. If you have something wrong in your ZenPack, you are doomed because Zenoss doesn't tell you too much useful information, especially when you use Zenoss web. For example, I deleted MANIFEST.in in the folder, and the egg was built without the folders libexec and objects/objects.xml. After I installed this egg, ZenPack appears in the webpage after I run "zopectl restart", but it never worked as I expected.