This material is copyright and is licensed for the sole use by Kliwon Klimis on 28th October 2008 425 cilce, , frood, grradt, 525254
Chapter 9
A Look at Configuring the RSS Zimlet
One of the more popular Zimlets, at least in my experience, is the RSS Zimlet. What this Zimlet allows the user to do is to subscribe to, and view, an RSS syndicated feed in the web-based email client. The feed is displayed in place of the calendar in the lower left hand corner of the screen.
There are two reasons this is a good test Zimlet for us to look at. The first is from a security standpoint, this Zimlet is an excellent example of how although Zimlets are client side programs that are usually configured by the user with preferences, they are still secured on the server side. The RSS Zimlet has a server-side configuration file that lists all of the websites in which users are allowed to receive feeds from. Only an administrator has access to add or delete allowed sites from this file. This configuration is done on a global server level.
The second reason is that the only way for an administrator to make changes to the configuration file, to allow or disallow access to particular feeds, is through using command line tools.
Let's take a moment to look at the RSS feed from the user perspective, and then we will move on to look at how to configure the Zimlet for access to additional RSS feeds from websites.
The RSS Zimlet in Action
The RSS Zimlet can be found in the Navigation Pane, under Zimlets. To configure the Zimlet and add feeds to it, you will need to follow these steps:
1.Login to the Zimbra client (http://zimbra.emailcs.com) as the Worker.
2.In the Navigation Pane, right-click on the RSS Zimlet and select Preferences.
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This material is copyright and is licensed for the sole use by Kliwon Klimis on 28th October 2008 425 cilce, , frood, grradt, 525254
The World of Zimlets
3.The RSS Zimlet can store up to five RSS feeds.
4.Each feed (1–5) is numbered and the active feed number should be entered in the "Select feed to use" textbox.
5.The RSS Zimlet will only display one feed at a time.
6.Once completed, click OK.
7.To view the current feed, double-click the RSS Zimlet.
8.The feed should display at the lower-left-hand corner of the screen, in place of the calendar.
This particular RSS Zimlet has two feeds listed. The first is from news.yahoo.com, the second from sans.org. As mentioned earlier, there is a configuration file that allows or denies access to particular website's RSS feeds. In this case, by default, yahoo.com is allowed and so therefore all of its sub-domains are available as RSS feeds. Sans.org, on the other hand, is not an allowed site and we will need to explicitly allow the site. Any site not listed in the configuration file is denied.
Allowing RSS Feeds for Additional Sites
If a user has added an RSS feed from an unauthorized website, when they click to activate the feed, an error message will pop up and no feeds will appear. To allow access to the website, the administrator will use some command line tools to add the website to the configuration file, therefore allowing the RSS Zimlet to access the feed. We will use SSH to connect to the server and make the changes.
1.SSH to the Zimbra server and login as a user on the server.
2.Switch the user to root by typing su - .
3.Switch from root to the Zimbra user by typing su – zimbra.
4.Change to the Zimlets-extra directory:
cd /opt/zimbra/zimbra-extras
5.We are now going to use the zmzimletctl tool to extract the configuration template for the RSS Zimlet. This will allow us to view the configuration file. We could also choose to copy and paste the information to a new file to overwrite the configuration.
zmzimletctl getConfigTemplate com_zimbra_rss.zip
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This material is copyright and is licensed for the sole use by Kliwon Klimis on 28th October 2008 425 cilce, , frood, grradt, 525254
Chapter 9
6.Copy the information that is displayed after using getConfigTemplate by highlighting the text that is returned. The information is also displayed below:
<zimletConfig name="com_zimbra_rss" version="1.1"> <global>
<property name="allowedDomains">*.google.com,*.yahoo.com,*. yimg.com,*.flickr.com,*.economist.com,pheedo.com</property>
</global>
</zimletConfig>
7.Create a new configure_template.xml file.
viconfigure_template.xml
8.Paste the configuration information into the file. Type i to insert and then right-click to paste.
9.Add sans.org (and any of its sub-domains) to the list of allowed sites. This would be simply add the domain name between the allowedDomains tags.
*.sans.org
10. Save the configuration file.
:wq!
11. Replace the configuration file for the RSS Zimlet. zmzimletctl configure configure_template.xml
12. Restart tomcat so the users will have the changes effective on the client side. tomcat restart
13. Test the new changes by activating the RSS Zimlet in the Web Client.
The zmzimletctl utility could be used to manage all aspects of the Zimlets including installing, deploying, disabling, as well as controlling access to Zimlets. Although the
GUI tools in the Administration Console can help with basic administration of the
Zimlets, it is important to understand how to use the built-in command-line (shell) tools to become a more effective administrator of the Zimbra Collaboration Suite.
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This material is copyright and is licensed for the sole use by Kliwon Klimis on 28th October 2008 425 cilce, , frood, grradt, 525254
The World of Zimlets
Summary
In this chapter, we took a brief look at the third-party applications and "mashups" called Zimlets that are an effective set of tools and programs that add more functionality to the Zimbra Web Client. Specifically, this chapter covered an
overview of Zimlets and their functionality, the integration of Zimlets into email and calendaring, managing Zimlets from the Administration Console, and Introducing the Zmzimletctl utility
To me, Zimlets are what makes the difference from the Zimbra Collaboration Suite being a less expensive, more secure, an easier to manage replacement to Microsoft
Exchange and other commercial messaging and collaboration suites, to Zimbra becoming a key and beneficial part of any messaging infrastructure.
You can develop your own Zimlets or use some of the one shared by other people. You can get some on Zimbra's gallery : http://gallery.zimbra.com/.
In our next chapter, we will discuss one of the most important parts of any server deployment, backup (and restore).
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This material is copyright and is licensed for the sole use by Kliwon Klimis on 28th October 2008 425 cilce, , frood, grradt, 525254
Backup and Restore
A systems administrator's worst nightmare is the call, page, text message, or any other alarm, informing you that your server is down. Especially a server that is so instrumental and imperative to any organization, like the messaging server. Recently, I had an Exchange 2003 Enterprise Server crash, and although I had a
backup of the Mailbox Store and the System State of the Windows operating system it was installed on, restoring the system took hours. I mean almost an entire business day wasted. Below are the basic steps I needed to go through to bring the server back up. Keep in mind, the box had a hardware RAID card error and a new server had to be used to host the Exchange Server.
1.Install Windows 2003 Standard Edition on a new box.
2.Apply all of the service packs to the server. They needed to match the service pack and patch level of the previous server.
3.Install the backup client, for the backup software.
4.Restore only System State first.
5.Reboot into Active Directory Restore mode.
6.Restore Active Directory.
7.Reboot system and install Exchange 2003.
8.Apply service pack to Exchange 2003.
9.Restore the Information Store to Exchange.
Now, it may appear pretty straightforward to restore the box. I mean, I only needed to go through nine steps. Well, each step probably had three to four items to complete and the clock was ticking. Eventually, the server came back up and everyone had all of their emails and settings. That day, I decided there must be an easier solution for email. From restoring mailboxes to the entire server, there needs to be a better way. I needed a system with a faster, more efficient way to keep the messaging infrastructure available to the users.