Podcasting Backbone Guide
Fall 2005 Podcast Backbone Guide Fall 2005
Contents
Podcasting with Weblog Server 3 Description 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 10 Description 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 13 Description 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 Guide 2 Fall 2005
Deleting a User’s Blogs and Podcasts from the Server 18 Description 18 Tools 18 Preparation 18 Deleting a blog 19
Creating Templates 20 Description 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 the U.S. and other countries. Apple Remote Desktop and Finder are trademarks of Apple Computer, Inc. Podcast Backbone Guide 3 Fall 2005
Podcasting with Weblog Server
Description Enable 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
Preparation Mac OS X Server should be installed and running on your server. If you are administering the server remotely, the Mac OS X Server administration tools must be installed on your management workstation. Your server should have a dedicated IP address and a valid DNS configuration with functioning forward and reverse lookups. 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 to Weblog Server, and iTunes is used to subscribe to the podcast.
Serving Podcasts with Weblog Server Mac OS X Server version 10.4 and later includes a weblog service. This service makes it easy for users to create personal or group blogs. Upgrade to Mac OS X Server version 10.4.3 which includes the latest updates to the blojsom, the Open Source blog engine. This guide is based on Mac OS X Server version 10.4.3. Creating a podcast couldn’t be simpler: Enable Weblog Server and users can create podcasts from their blog. The Apple implementation has an easy-to-use browser based interface for users. Podcast Backbone Guide 4 Fall 2005
Network Configurations for Podcasting When delivering your podcasts, your web server transfers large files to clients. Your server should have a fast connection, ideally in the machine room on your institution’s network backbone. If you have clients on the Internet, podcasts are delivered over your institution’s Internet connection. If your server becomes popular on the Internet, you could see a spike in traffic from your server over the Internet link.
Enabling Weblog Server Weblog Server is an optional component of the Mac OS X Server web service. To enable the weblog, follow the steps outlined below:
1 Open the Server Admin application and connect to Mac OS X Server as an administrative user.
2 Click Web in the Computers & Services pane, then click the Start Service button in the toolbar at the top of the window. Podcast Backbone Guide 5 Fall 2005
3 With Web still selected in the Computers & Services pane, click the Weblogs button and select Enable Weblogs.
Note: You can change the default location of user and group weblogs by selecting a different Weblog folder.
Connecting to Weblog Server from a Client Clients can use a web browser to access Weblog Server running on your server. Use the address bar in your browser to access http://
Posting Podcasts to Weblog Server 1 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:
Enter the user or group short name here.
2 The next page shows the weblog for that user or group. Use the Login button to authenticate as the user or a user in the group.
Once you have successfully logged in, you can create new categories, entries, or change blog settings. Categories allow you to organize your blog posts. Entries are used to create a blog post and individual podcasts. Note: Your blog may look different based on the theme selected in the blog settings. Podcast Backbone Guide 7 Fall 2005
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 in the title and description fields. What you enter here is reflected in iTunes when a client accesses the podcast. The title will appear as the Podcast column in iTunes. The description will appear in the Description column. Podcast Backbone Guide 8 Fall 2005
5 Click the Advanced button to upload your podcast audio file with the post. Click the Choose 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 other blogs 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 Browser Once 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://
Subscribing to the Weblog with iTunes To subscribe to the podcast in iTunes, simply click the RSS|Podcast link.
Click here to subscribe in iTunes.
Creating iTunes Links to Weblog Podcasts If you need to create an HREF link to a podcast, Control-click the iTunes RSS|Podcast link 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://
Creating Podcasting Groups
Description Use Workgroup Manager to set up a group for podcasting. Weblog Server supports both individual users and groups. For many education environments, you may want to configure groups for podcasting. For example, you could create a High School French group for all faculty members that teach French in the high school.
Tools • Mac OS X Server 10.4.3 • Users and Groups configured in Workgroup Manager
Preparation Mac OS X Server 10.4.3 must be installed. The web server should be running, and the Enable Weblog option should be selected. (For more information, see “Podcasting with Weblog Server,” earlier in this document.)
Group Setup Overview Workgroup Manager is the Mac OS X Server management tool for managing users and groups in the local directory and in an institution-wide directory system. Groups automatically have a weblog when Weblog Server is enabled. Any user in the group is able to create and edit weblog entries and categories.
Using Workgroup Manager to Configure Podcasting Groups 1 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 an administrator’s user name and password. For example: Podcast Backbone Guide 11 Fall 2005
3 Mac OS X Server supports a local directory of users and groups specific to a server. It can 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 Workgroup Manager:
4 Click Accounts in the toolbar, then click the Groups button.
Groups button Podcast Backbone Guide 12 Fall 2005
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 drawer appears with a list of all users in the directory. Drag users from the drawer into the Members pane. Change the directory that you are browsing if necessary.
Change the directory.
Drag users into the Members pane.
Posting and Accessing a Group’s Podcasts Follow the steps in “Posting Podcasts to Weblog Server,” earlier in this document, to create a weblog and podcast entries for the group. Any user in the group will be able to create and edit Categories and Entries. Podcast Backbone Guide 13 Fall 2005
Controlling Access to Weblog Server
Description Use service access controls and firewalls to limit podcasting and blogging capabilities. It may not be appropriate for all users to be able to create podcasts and other weblog entries. Service access controls can limit blog editing to specific users and groups. An institution or department might also want to limit access to Weblog Server to an internal network using the Mac OS X Server Firewall.
Tools • Mac OS X Server 10.4.3 • Users and Groups configured in Workgroup Manager • Firewall Service configured with Server Admin
Preparation Mac OS X Server 10.4.3 must be installed. The web server should be running, and the Enable Weblog option should be selected. (For more information, see “Podcasting with Weblog Server,” earlier in this document.)
Access Control Overview There are a few approaches to access control with Weblog Server. It may not be appropriate 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 limit access to specific users or groups. You may also want to limit network access to blogs and podcasts. This can be accomplished by using the Mac OS X Server firewall.
Controlling Users Who Can Post to Weblog Server First, look at limiting who can create a blog on the server. Mac OS X Server supports service access controls. These access controls provide a way to limit access to a service to specific users and groups. The users and groups are defined in Workgroup Manager. The Access Controls for Services are defined in Server Admin. Podcast Backbone Guide 14 Fall 2005
1 Define the users and groups in Workgroup Manager. For example, you might want to create a group named “bloggers.” Anyone in this group will be able to create blogs 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 the Access 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 the main window as shown. e When you’re finished, click the Save button. Podcast Backbone Guide 15 Fall 2005
When an unauthorized user tries to log in to the blog server to create posts, the user will see the following dialog:
Note: If a user’s ability to blog is removed, you may also want to delete his or her blog entries from the server. Follow the instructions in “Deleting a User’s Blogs and Podcasts from the Server,” later in this document.
Limiting Access to Weblog Server Using Mac OS X Server Firewall An institution might want to limit access to blogs and podcasts to specific areas on their internal network. Refer to Mac OS X Server Network Services documentation for complete documentation on Firewall configuration. The weblog service runs as part of the web server. By default, the web server runs on port 80, and the web server performance cache on port 16080. Limiting access to these ports provides a mechanism 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 Settings button. Under Address groups, you should see a preconfigured group for the local network. In this case, the group is named “192.168-net.” New groups can be created by clicking the “+” button. Groups can be edited by double-clicking the group name. The 192.168-net is defined as follows: Podcast Backbone Guide 16 Fall 2005
2 Click the Services button. For this simple example, you’ll allow all traffic to and from the server on the 192.168.x.x network. Podcast Backbone Guide 17 Fall 2005
3 Next, you’ll limit access to any other network. Deselect any port that will be protected by the server’s built-in firewall. In this example, you have limited all external access except for SSH.
4 Start the Firewall service by clicking the Start Service button. In this example, clients on the 192.168.x.x network will have full access to the server, and clients from any other network will be restricted to SSH. Podcast Backbone Guide 18 Fall 2005
Deleting a User’s Blogs and Podcasts from the Server
Description Delete a blog from the server. From time to time, it may be necessary to delete a blog from the server. For example, you might want to revoke a student’s ability to blog and remove their existing blog site.
Tools • Mac OS X Server 10.4.3 or later • Finder access to the blog server • Web Browser
Preparation Mac OS X Server 10.4.3 must be installed. The web server should be running, and the Enable Weblog option should be selected. (For more information, see “Podcasting with Weblog Server,” earlier in this document.) This procedure assumes that you have 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’s blog folders before deleting them from the server in case they are needed in the future. You will need the user’s or group’s short name to locate their blog files on the server. Podcast Backbone Guide 19 Fall 2005
Deleting a Blog A user’s blog entries are managed by three folders on the server. The first folder contains the user’s blog entry text. When you set up Weblog Server, you specify where 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’s short user’s name from the directory specified. Navigate to the weblog folder in the Finder, and drag the folder to the Trash. If you only want to delete all the user’s blog entries, but still have them listed on the main blog site, you can stop here. You can navigate 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), you need to delete the “meta” information for the user’s blog site. This information is stored 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 the Trash. 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 to the 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. This removes the blog from the main blog listing page. Note: You will need administrator privileges to delete this folder. Podcast Backbone Guide 20 Fall 2005
Creating Templates
Description Copy 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 the appearance of weblog pages. This doesn’t affect how podcasts function, but does impact the HTML representation of the blog in a web browser. This section covers copying 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
Preparation Mac OS X Server 10.4.3 must be installed. The web server should be running, and the Enable Weblog option should be selected. (For more information, see “Podcasting with Weblog Server,” earlier in this document.) This procedure assumes that you have access to the Finder on the server either through a locally attached display, keyboard, and mouse or remotely via Apple Remote Desktop.
CSS Template Overview CSS is a web technology that provides a logical separation between content and interface. Using CSS, the same content can be represented in different ways, based on the CSS template that is referenced. Apple includes several CSS templates with Weblog Server. An easy way to create a custom template is to duplicate one of the templates 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 Podcast Backbone Guide 21 Fall 2005
Creating a Custom CSS Template 1 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 comes from a file in the strings folder of Weblog Server. Weblog Server includes strings for German (de.properties), English (en.properties), French (fr.properties), and Japanese (ja.properties). In this section, it is assumed that some clients are using English in their web browser. On the server, double-click the en.properties file to open it in TextEdit. Scroll to the bottom of the file where you will see a section that begins with the comment: # Template full names Find the name of the template you selected as a starting point in step 1. Note the associated template name. For example, if the “Grey” template was selected in step 1 as 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 ends in .css (this is the stylesheet you’ll modify) and the other ends in .js (you won’t modify 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 template section, add a new line for the template you copied. In this example, this is template.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. The template you duplicated should now appear in the Theme pop-up menu. Podcast Backbone Guide 22 Fall 2005
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 customize these files. This example uses CSSEdit, an editor from MacRabbit software. Opening the 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 to modify it.
8 In this example, you’ll modify the #header_logo_img style with a custom graphic for the Biology department. Clicking that style in CSSEdit provides a graphical interface for editing the attributes of that style. The custom graphic has different dimensions: Podcast Backbone Guide 23 Fall 2005
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 stores graphics: /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 change settings. Select the Biology blog template and save the settings. The new graphic should be displayed on the blog site. Podcast Backbone Guide 24 Fall 2005
Glossary
AAC—A modern audio codec that is part of the MPEG-4 specification. At any given bit rate, AAC delivers higher quality audio than the older MP3 codec. Bandwidth—In a network connection, bandwidth refers to the rate that data can be delivered. The maximum bandwidth of an analog modem is 57,600 kilobits per second (or 56K). Broadband connections such as DSL or cable modems have much more bandwidth available, typically at least 500 kilobits per second (kbits/s). In a local 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 a media file is compressed. For example, a media file compressed to be delivered in real time over a 56K modem would need to be compressed at a bit rate of less than 56 kbits/s. The bit rate is also referred to as data rate. Codec—An acronym for compressor/decompressor. Uncompressed audio and video files are very large. As a result, media delivered on the Internet is compressed. When a client plays the media, it is decompressed. Enhanced podcast—In addition to audio-only podcasts, Apple has created a specification for enhancing audio podcasts. An enhanced podcast can be divided into 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 URL that links to a website. Metadata—Information about information is called metadata. For example, an audio 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 for digital media. For example, DVD video uses the MPEG-2 specification. The MPEG-4 specification defines a file format and set of codecs for Internet delivery of digital media. MP3—A compressed audio file format that can be used with podcasting. This audio format was originally created as the audio portion of an MPEG-1 file. It is an older codec—quality at any given bit rate will be lower than media compressed with newer codecs. RSS—Really Simple Syndication or Rich Site Summary is an Internet technology that provides a method for Internet clients to subscribe to content delivered by web servers. RSS version 2 added the ability for multimedia enclosures and is the basis for 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 RSS feeds. XML—This acronym stands for eXtensible Markup Language. The syntax of XML is similar to HTML. This file format is used to deliver RSS feeds over the Internet. The XML file contains metadata about the RSS feed. With podcasts, enclosure metadata contains the location of the actual audio file on the Internet.