Podcasting Backbone Guide - University of Minnesota...

Podcasting Backbone GuideFall 2005

Contents

Podcasting with Weblog Server 3Description 3

Tools 3

Preparation 3

Serving Podcasts with Weblog Server 3

Network Configurations for Podcasting 4

Enabling Weblog Server 4

Connecting to Weblog Server from a Client 5

Posting Podcasts to Weblog Server 6

Accessing the Weblog Post with a Web Browser 8

Subscribing to the Weblog with iTunes 9

Creating iTunes Links to Weblog Podcasts 9

Creating Podcasting Groups 10Description 10

Tools 10

Preparation 10

Group Setup Overview 10

Using Workgroup Manager to Configure Podcasting Groups 10

Posting and Accessing a Group’s Podcasts 12

Controlling Access to Weblog Server 13Description 13

Tools 13

Preparation 13

Access Control Overview 13

Controlling Users Who Can Post to Weblog Server 13

Limiting Access to Weblog Server using Mac OS X Server Firewall 15

Podcast Backbone GuideFall 2005

Deleting a User’s Blogs and Podcasts from the Server 18Description 18

Tools 18

Preparation 18

Deleting a blog 19

Creating Templates 20Description 20

Tools 20

Preparation 20

CSS Template Overview 20

Creating a Custom CSS Template 23

Glossary 24

© 2005 Apple Computer, Inc. All rights reserved.

Apple, the Apple logo, iTunes, Mac, and Mac OS are trademarks of Apple Computer, Inc., registered in theU.S. and other countries. Apple Remote Desktop and Finder are trademarks of Apple Computer, Inc.


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Podcasting with Weblog Server

DescriptionEnable weblog services, upload, and test your first podcast.

Tools• Mac OS X Server 10.4.3

• Weblog Server management via Server Admin

• Podcast audio file (.m4a, .m4b, or .mp3)

• Web browser

• iTunes

PreparationMac OS X Server should be installed and running on your server. If you areadministering the server remotely, the Mac OS X Server administration tools must beinstalled on your management workstation. Your server should have a dedicated IPaddress and a valid DNS configuration with functioning forward and reverselookups.

The audio file for your podcast must be edited and compressed for Internet delivery(see the Podcast Creation Guide). A web browser is used to post the podcast toWeblog Server, and iTunes is used to subscribe to the podcast.

Serving Podcasts with Weblog ServerMac OS X Server version 10.4 and later includes a weblog service. This service makesit easy for users to create personal or group blogs. Upgrade to Mac OS X Serverversion 10.4.3 which includes the latest updates to the blojsom, the Open Sourceblog engine. This guide is based on Mac OS X Server version 10.4.3. Creating apodcast couldn’t be simpler: Enable Weblog Server and users can create podcastsfrom their blog. The Apple implementation has an easy-to-use browser basedinterface for users.


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Network Configurations for PodcastingWhen delivering your podcasts, your web server transfers large files to clients. Yourserver should have a fast connection, ideally in the machine room on yourinstitution’s network backbone. If you have clients on the Internet, podcasts aredelivered over your institution’s Internet connection. If your server becomes popularon the Internet, you could see a spike in traffic from your server over the Internetlink.

Enabling Weblog ServerWeblog Server is an optional component of the Mac OS X Server web service. Toenable the weblog, follow the steps outlined below:

1 Open the Server Admin application and connect to Mac OS X Server as anadministrative user.

2 Click Web in the Computers & Services pane, then click the Start Service button inthe toolbar at the top of the window.


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3 With Web still selected in the Computers & Services pane, click the Weblogs buttonand select Enable Weblogs.

Note: You can change the default location of user and group weblogs by selectinga different Weblog folder.

Connecting to Weblog Server from a ClientClients can use a web browser to access Weblog Server running on your server.Use the address bar in your browser to access http://<server address>/weblog/.For example, if the server’s DNS address is www.demo.edu, enterhttp://www.demo.edu/weblog/.


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http://www.demo.edu

http://www.demo.edu/weblog

Posting Podcasts to Weblog Server1 By default, any user or group set up on the server has a weblog. To access the

weblog for a user or group, enter the short name in the weblog window:

2 The next page shows the weblog for that user or group. Use the Login button toauthenticate as the user or a user in the group.

Once you have successfully logged in, you can create new categories, entries, orchange blog settings. Categories allow you to organize your blog posts. Entries areused to create a blog post and individual podcasts.

Note: Your blog may look different based on the theme selected in the blogsettings.


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Enter the user or group short name here.

3 To create a podcast entry, click the New Entry button.

4 A dialog appears in which you can create a title and description for your entry. Fill inthe title and description fields. What you enter here is reflected in iTunes when aclient accesses the podcast. The title will appear as the Podcast column in iTunes.The description will appear in the Description column.


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5 Click the Advanced button to upload your podcast audio file with the post. Click theChoose File button to upload a podcast-compatible audio file.

Note: TrackBack is a mechanism used in a blog that shows a list of entries in otherblogs that refer to a post on the first blog. More information is available at this site:

http://en.wikipedia.org/wiki/Trackback

6 Click Save when you are finished.

Accessing the Weblog Post with a Web BrowserOnce your podcast entry is posted, it can be accessed via a web browser.Clients can get to a specific blog using the following URL:http://<server address>/weblog/<shortname>/. Podcasts appear as individualentries with a download link for the podcast audio file:


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http://en.wikipedia.org/wiki/Trackback

Subscribing to the Weblog with iTunesTo subscribe to the podcast in iTunes, simply click the RSS|Podcast link.

Creating iTunes Links to Weblog PodcastsIf you need to create an HREF link to a podcast, Control-click the iTunes RSS|Podcastlink on the blog site, then choose Copy Link from the shortcut menu.

Note: With a two-button mouse, right-click to copy the URL.

The link will be in the following format:

itpc://<server address>/weblog/<short name>/?flavor=rss2

This URL can be used in an HREF tag to link to the podcast from any website.


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Click here to subscribe in iTunes.

Creating Podcasting Groups

DescriptionUse Workgroup Manager to set up a group for podcasting.

Weblog Server supports both individual users and groups. For many educationenvironments, you may want to configure groups for podcasting. For example, youcould create a High School French group for all faculty members that teach Frenchin the high school.


• Users and Groups configured in Workgroup Manager

PreparationMac OS X Server 10.4.3 must be installed. The web server should be running, and theEnable Weblog option should be selected. (For more information, see “Podcastingwith Weblog Server,” earlier in this document.)

Group Setup OverviewWorkgroup Manager is the Mac OS X Server management tool for managing usersand groups in the local directory and in an institution-wide directory system. Groupsautomatically have a weblog when Weblog Server is enabled. Any user in the groupis able to create and edit weblog entries and categories.

Using Workgroup Manager to Configure Podcasting Groups1 Open the Workgroup Manager application.

Note: Workgroup Manager can be installed on any Mac OS X v10.4.x system.

2 Connect to Mac OS X Server with web and weblog services enabled. Use anadministrator’s user name and password. For example:


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3 Mac OS X Server supports a local directory of users and groups specific to a server. Itcan also be linked to institutional directory systems such as Apple’s Open Directory.Choose the directory you want to manage from the pop-up menu in WorkgroupManager:

4 Click Accounts in the toolbar, then click the Groups button.


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Groups button

5 Click the New Group button on the toolbar. Enter a name, short name, and group ID.

6 Click the button with a + sign next to the Members pane of the group. A drawerappears with a list of all users in the directory. Drag users from the drawer into theMembers pane. Change the directory that you are browsing if necessary.

Posting and Accessing a Group’s PodcastsFollow the steps in “Posting Podcasts to Weblog Server,” earlier in this document, tocreate a weblog and podcast entries for the group. Any user in the group will beable to create and edit Categories and Entries.


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Change the directory.

Drag users into the Members pane.

Controlling Access to WeblogServer

DescriptionUse service access controls and firewalls to limit podcasting and bloggingcapabilities.

It may not be appropriate for all users to be able to create podcasts and otherweblog entries. Service access controls can limit blog editing to specific users andgroups. An institution or department might also want to limit access to WeblogServer to an internal network using the Mac OS X Server Firewall.


• Users and Groups configured in Workgroup Manager

• Firewall Service configured with Server Admin


Access Control OverviewThere are a few approaches to access control with Weblog Server. It may not beappropriate to give all users and groups the privilege to create blogs and podcasts.With Mac OS X Server, Service Access Control Lists (SACLS) can be used to limitaccess to specific users or groups. You may also want to limit network access toblogs and podcasts. This can be accomplished by using the Mac OS X Server firewall.

Controlling Users Who Can Post to Weblog ServerFirst, look at limiting who can create a blog on the server. Mac OS X Server supportsservice access controls. These access controls provide a way to limit access to aservice to specific users and groups. The users and groups are defined in WorkgroupManager. The Access Controls for Services are defined in Server Admin.


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1 Define the users and groups in Workgroup Manager. For example, you might wantto create a group named “bloggers.” Anyone in this group will be able to createblogs and podcasts. Add users to the group as appropriate.

2 Define the Access Controls in Server Admin.

a Click the name of your server in the Computers & Services pane, then click theAccess button.

b Deselect “Use same access for all services.”

c Select Weblog, then select the “Allow only users and groups below” option.

d Click the “+” button to display the drawer with users in the selected directory.Drag groups or users that will be able to log in and create blog entries in themain window as shown.

e When you’re finished, click the Save button.


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When an unauthorized user tries to log in to the blog server to create posts, theuser will see the following dialog:

Note: If a user’s ability to blog is removed, you may also want to delete his or herblog entries from the server. Follow the instructions in “Deleting a User’s Blogs andPodcasts from the Server,” later in this document.

Limiting Access to Weblog Server Using Mac OS X ServerFirewallAn institution might want to limit access to blogs and podcasts to specific areas ontheir internal network. Refer to Mac OS X Server Network Services documentationfor complete documentation on Firewall configuration. The weblog service runs aspart of the web server. By default, the web server runs on port 80, and the webserver performance cache on port 16080. Limiting access to these ports provides amechanism to limit access to Weblog Server and podcasts.

Here is an example of limiting access to web services to a local 192.168.x.x network:

1 Click Firewall in the Computers & Services pane of Server Admin. Click the Settingsbutton. Under Address groups, you should see a preconfigured group for the localnetwork. In this case, the group is named “192.168-net.” New groups can be createdby clicking the “+” button. Groups can be edited by double-clicking the group name.The 192.168-net is defined as follows:


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2 Click the Services button. For this simple example, you’ll allow all traffic to and fromthe server on the 192.168.x.x network.


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3 Next, you’ll limit access to any other network. Deselect any port that will beprotected by the server’s built-in firewall. In this example, you have limited allexternal access except for SSH.

4 Start the Firewall service by clicking the Start Service button. In this example, clientson the 192.168.x.x network will have full access to the server, and clients from anyother network will be restricted to SSH.


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Deleting a User’s Blogs andPodcasts from the Server

DescriptionDelete a blog from the server.

From time to time, it may be necessary to delete a blog from the server. Forexample, you might want to revoke a student’s ability to blog and remove theirexisting blog site.

Tools• Mac OS X Server 10.4.3 or later

• Finder access to the blog server

• Web Browser

PreparationMac OS X Server 10.4.3 must be installed. The web server should be running, and theEnable Weblog option should be selected. (For more information, see “Podcastingwith Weblog Server,” earlier in this document.) This procedure assumes that youhave access to the Finder on the server either through a locally attached display,keyboard, and mouse or remotely via Apple Remote Desktop.

This is a destructive process. It’s a good idea to make a backup copy of the user’sblog folders before deleting them from the server in case they are needed in thefuture. You will need the user’s or group’s short name to locate their blog files onthe server.


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Deleting a BlogA user’s blog entries are managed by three folders on the server. The first foldercontains the user’s blog entry text. When you set up Weblog Server, you specifywhere blogs are stored in Server Admin:

1 The first step for deleting a blog is to delete the folder with the user’s or group’sshort user’s name from the directory specified. Navigate to the weblog folder in theFinder, and drag the folder to the Trash. If you only want to delete all the user’s blogentries, but still have them listed on the main blog site, you can stop here. You cannavigate to a specific folder by choosing Go > Go to Folder in the Mac OS X Finder.

2 If you also want to remove all of the user’s enclosures (including podcasts), youneed to delete the “meta” information for the user’s blog site. This information isstored in the path:

/Library/Tomcat/blojsom_root/webapps/ROOT/blojsom_resources/meta

Find the folder in this path with the user’s or group’s shortname and drag it to theTrash.

Note: You will need administrator privileges to delete this folder.

3 Finally, to remove the user’s or group’s blog from the main weblog page, navigate tothe path:

/Library/Tomcat/blojsom_root/webapps/ROOT/WEB_INF

Find the folder with the user or group’s short name and drag it to the Trash. Thisremoves the blog from the main blog listing page.

Note: You will need administrator privileges to delete this folder.


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Creating Templates

DescriptionCopy and modify a CSS template.

Weblog Server uses CSS templates to configure the look and feel of weblog posts.Templates can be copied, edited, or created from scratch to customize theappearance of weblog pages. This doesn’t affect how podcasts function, but doesimpact the HTML representation of the blog in a web browser. This section coverscopying an existing template and modifying it with a CSS editing tool.

Tools• Weblog Server

• Text editor or CSS editing application with a graphical user interface

• Web browser


This procedure assumes that you have access to the Finder on the server eitherthrough a locally attached display, keyboard, and mouse or remotely via AppleRemote Desktop.

CSS Template OverviewCSS is a web technology that provides a logical separation between content andinterface. Using CSS, the same content can be represented in different ways, basedon the CSS template that is referenced. Apple includes several CSS templates withWeblog Server. An easy way to create a custom template is to duplicate one of thetemplates provided by Apple to use as a starting point.

The template files are stored in:

/Library/Tomcat/blojsom_root/webapps/ROOT/blojsom_resources/stylesheets

The images references by template files are stored in:

/Library/Tomcat/blojsom_root/webapps/ROOT/blojsom_resources/images

The names of the templates are stored in:

/Library/Tomcat/blojsom_root/webapps/strings


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Creating a Custom CSS Template1 Start by exploring the provided templates:

a Access a blog on the server, log in, and click the Settings button.

b Select the different templates from the Theme pop-up menu.

c Click the Save button.

d Choose one of these templates as a starting point.

2 The name of the template selected in the Theme pop-up menu in step 1 comesfrom a file in the strings folder of Weblog Server. Weblog Server includes strings forGerman (de.properties), English (en.properties), French (fr.properties), and Japanese(ja.properties). In this section, it is assumed that some clients are using English intheir web browser. On the server, double-click the en.properties file to open it inTextEdit. Scroll to the bottom of the file where you will see a section that beginswith the comment:

# Template full names

Find the name of the template you selected as a starting point in step 1. Note theassociated template name. For example, if the “Grey” template was selected in step 1as the starting point, note the line:

template.apple_layout=Grey

3 Using the information collected in step 2, duplicate the template files. Navigate to:

/Library/Tomcat/blojsom_root/webapps/ROOT/blojsom_resources/stylesheets

Find the files that match the name from step 2. There should be two files: One endsin .css (this is the stylesheet you’ll modify) and the other ends in .js (you won’tmodify this file). In this example, those files would be “apple_layout.css” and“apple_layout.js.”

Select both files in the Finder using the Shift key, then choose File > Duplicate.Rename the copies. In this example, they’ll be named “biology.css” and “biology.js.”

4 Go back to the en.properties file from step 2. After the last line in the templatesection, add a new line for the template you copied. In this example, this istemplate.biology=Biology.

5 Save the en.properties file. For the new template to appear, reload the page.

6 From a web browser, go to a blog site, log in, and click the Settings button. Thetemplate you duplicated should now appear in the Theme pop-up menu.


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7 Now that there is a new template, you can customize it. The .css file is a text file.There are a variety of graphical CSS editing tools that make it easy to customizethese files. This example uses CSSEdit, an editor from MacRabbit software. Openingthe biology.css file with CSSEdit, you’ll see something like the following window.

The Styles column lists all the defined styles in this .css file. You can click any style tomodify it.

8 In this example, you’ll modify the #header_logo_img style with a custom graphic forthe Biology department. Clicking that style in CSSEdit provides a graphical interfacefor editing the attributes of that style. The custom graphic has different dimensions:


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9 The .css file references a different file that contains the Biology department’s logo.Change this style to reference that graphic file:

10 Copy the “biology.jpg” graphic file into the folder where Weblog Server storesgraphics:

/Library/Tomcat/blojsom_root/webapps/ROOT/blojsom_resources/images

Save the biology.css file.

11 Using a web browser, access a blog on the server. Log in to the blog to changesettings. Select the Biology blog template and save the settings.

The new graphic should be displayed on the blog site.


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Glossary

AAC—A modern audio codec that is part of the MPEG-4 specification. At any givenbit rate, AAC delivers higher quality audio than the older MP3 codec.

Bandwidth—In a network connection, bandwidth refers to the rate that data can bedelivered. The maximum bandwidth of an analog modem is 57,600 kilobits persecond (or 56K). Broadband connections such as DSL or cable modems have muchmore bandwidth available, typically at least 500 kilobits per second (kbits/s). In alocal area network, or LAN, a slow connection is 10 megabits or 10,000 kbits/s.

Bit rate—This is another way to refer to bandwidth. It is also used to specify how amedia file is compressed. For example, a media file compressed to be delivered inreal time over a 56K modem would need to be compressed at a bit rate of less than56 kbits/s. The bit rate is also referred to as data rate.

Codec—An acronym for compressor/decompressor. Uncompressed audio and videofiles are very large. As a result, media delivered on the Internet is compressed. Whena client plays the media, it is decompressed.

Enhanced podcast—In addition to audio-only podcasts, Apple has created aspecification for enhancing audio podcasts. An enhanced podcast can be dividedinto chapters, allowing clients to quickly navigate to specific parts of the podcast.Each chapter can have an associated piece of artwork. Chapters can also have a URLthat links to a website.

Metadata—Information about information is called metadata. For example, anaudio file contains audio information. The name of the person that created the file,length of the file, title of the file, description, and so on are metadata.

MPEG-4—The Moving Picture Experts Group defines and licenses specifications fordigital media. For example, DVD video uses the MPEG-2 specification. The MPEG-4specification defines a file format and set of codecs for Internet delivery of digitalmedia.

MP3—A compressed audio file format that can be used with podcasting. This audioformat was originally created as the audio portion of an MPEG-1 file. It is an oldercodec—quality at any given bit rate will be lower than media compressed withnewer codecs.

RSS—Really Simple Syndication or Rich Site Summary is an Internet technology thatprovides a method for Internet clients to subscribe to content delivered by webservers. RSS version 2 added the ability for multimedia enclosures and is the basisfor podcasting. With the release of iTunes 4.9, Apple provided an easy way to find,subscribe, and listen to podcasts. Podcasts are delivered over the Internet as RSSfeeds.

XML—This acronym stands for eXtensible Markup Language. The syntax of XML issimilar to HTML. This file format is used to deliver RSS feeds over the Internet. TheXML file contains metadata about the RSS feed. With podcasts, enclosure metadatacontains the location of the actual audio file on the Internet.


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