- 1 What are Repositories?
- 2 Adding Repositories in Ubuntu
- 3 Ubuntu Software Tab
- 4 Third-Party Software Tab
- 5 Updates Tab
- 6 Authentication Tab
- 7 Statistics
- 8 Integration with Add/Remove
- 9 Exploring the Repositories
- 10 Other Links
What are Repositories?
There are literally thousands of Ubuntu programs available to meet the needs of Ubuntu users. Many of these programs are stored in software archives commonly referred to as repositories. Repositories make it very easy to install new software onto Ubuntu using an Internet connection, while also providing a high level of security, as each program available in the repositories is thoroughly tested and built specifically for each version of Ubuntu. The Ubuntu software repositories are organized into four separate areas or "components", according to the the level of support offered by Ubuntu and whether or not the program in question complies with Ubuntu's Free Software Philosophy. The repository components are:
- Main - Officially supported software.
- Restricted - Supported software that is not available under a completely free license.
- Universe - Community maintained software, i.e. not officially supported software.
- Multiverse - Software that is not free.
For more information regarding the Ubuntu Repository components, click here. The Ubuntu Install CDs contain software from the "Main" and "Restricted" components of the repositories. Once your system is made aware of the Internet-based locations for these repositories, many more software programs are available for installation. By using the software package management tools already installed on your system, you can search for, install and update any piece of software directly over the Internet, without the need for the CD.
Adding Repositories in Ubuntu
This section describes how to manage software repositories in Ubuntu 8.04 (Hardy Heron), Ubuntu 8.10 (Intrepid Ibex), and Ubuntu 9.04 (Jaunty Jackalope). For Kubuntu please see Kubuntu repository management. The operations described on this page modify the software repositories configuration file located at
Software sources can also be managed by making direct modifications to this file using the command line. If you prefer to use the command line instead of a graphical user interface, see Managing Repositories from the Command Line instead. GUI-based repository management is normally accomplished via the "Software Sources" panel. This panel can be accessed via two menus:
- Software Sources: System > Administration > Software Sources.
- Synaptic: System > Administration > Synaptic >> Settings >> Repositories.
- You will have to enter your password to gain access to the page.
Ubuntu Software Tab
Adding Ubuntu Software Repositories
The "Ubuntu Software" tab displays a list of repositories or "Channels". For a detailed description of these repositories, visit the Ubuntu here page.
- The following repositories are enabled by default:
- "Canonical-supported Open Source software (main)"
- "Proprietary drivers for devices (restricted)" [hardware-dependent]
- "Source Code"
- Note: In Ubuntu 9.04 (Jaunty), the main, universe, restricted and multiverse repositories are enabled by default.
- Select other repositories to gain access to proprietary drivers, copyrighted material, source code, etc.
- "Community-maintained Open Source software - (universe)"
- "Proprietary drivers for devices (restricted)" - Commonly used software which is not available under a completely free license. This software is supported by the Ubuntu team.
- "Software restricted by copyright or legal issues (multiverse)" - Software that is "not free" and may require licensing. This software is not supported.
- Select "Close" to save your changes. A dialog box should appear, asking whether you'd like to update the list of repositories. Select "Reload" to update the list.
The Close, Reload, and Revert buttons each perform special functions with regard to the repository pages.
- Close. The 'Close' button must be selected to execute any change(s). If the action would change system files, they are written at this time.
- Reload. Any time a setting is changed which alters a repository setting the 'Reload' button should be selected to allow the applicable repository database to be updated. Repository information will not normally be updated until the 'Reload' button is selected. If you do not wish to use 'Reload', select 'Close' to exit without updating the database.
- Revert. The 'Revert' button erases changes made since the last save. It merely cancels pending changes which have not been executed, returning the selections to their prior state. The button does not return system files to the original installation settings.
The install CD-ROM may be selected or deselected from this window.
- If selected, the system will attempt to search the CD-ROM during package installs.
- If selected but the CD is not inserted, a message will be generated requesting it's insertion.
- Deselect the CD-ROM if you do not plan to use it to install software. This will also end messages to insert the CD-ROM during internet installs.
Third-Party Software Tab
Adding Canonical Partner Repositories
The "Third-Party Software" tab is where you will be able to add the Canonical Partner Repositories. You will see two Canonical Partner repositories listed - one for applications and another for source code (src). The partner repositories offer access to proprietary and closed-source software and are not enabled by default. Users must specifically enable these 'partner' repositories. Select "Close" and "Reload" to save and update the database if you chose to add either or both of them. <<Anchor(other)>>
Other CD-ROM/DVD sources may be added on this tab. Click the "Add CD-ROM" button after inserting a CD-ROM containing packages. After adding the CD-ROM/DVD, it will be searched for packages during installation requests.
Adding Other Repositories
There are times when you might want to add non-Ubuntu repositories to your list of software sources. Make sure that all repositories you add in this way have been tested and are known to work on Ubuntu systems. Repositories that are not designed to work with your version of Ubuntu can introduce inconsistencies in your system and might force you to re-install. For example, some software cannot be distributed by Ubuntu due to patent and licensing restrictions in some countries (see the RestrictedFormats page for examples). You might want to add repositories that offer such software. To add additional repositories, click the "Add" button, and enter the location of the repository in the window. <<Anchor(aptline)>>
- Enter the apt line into the dialog box. It should look something like this:
deb http://ppa.launchpad.net/fta/ubuntu hardy main
For an explanation of the different parts of the apt line, see the [[UbuntuHelp:[edit|Editing Repositories]]] section below. Some web sites provide instructions on how to add their repositories to each version of Ubuntu. You can also download an official repository for your machine architecture (i.e. i386) and use it offline (see AptGet/Offline/Repository). <<Anchor(edit)>>
To make changes to a software source, select it in the list and click the Edit button. A dialog box displays the apt line, broken up into its components.
- Type Software sources are designated as "binary" (deb) for software in binary format or "Source" (src) for source code format. Select the option that corresponds to the repository.
- URI Enter a valid Uniform Resource Indicator or URI for the software repository. Here's a list of examples:
- cdrom <
- ftp <
- http <
- smb (works only when the computer is connected to a Samba share) <
- nfs (works only if the computer is connected to a NFS share) <
- Distribution <
> Select the name of the distribution or the name of the distribution version. <
>(hardy [[UbuntuHelp:[edit|in the example above]]].)
- Components <
> Select the repository section to access. Add more sections separated by spaces. <
>(The [[UbuntuHelp:[edit|example repository]]] has a partner section.)
- Comment <
>Add a comment to describe the repository for easier reference.
Removing & Disabling Repositories
- To disable a repository temporarily, untick the checkbox next to the source. The user can restore the repository by selecting it.
- To remove a software repository ("Channel") permanently from the list, highlight the repository and click on the "Remove" button.
The "Updates" tab is where you will be able to set when and how Ubuntu receives system updates.
- "Important Security Updates (hardy-security)". Patches for security vulnerabilities in Ubuntu packages. They are managed by the Ubuntu Security Team and are designed to change the behavior of the package as little as possible -- in fact, the minimum required to resolve the security problem. As a result, they tend to be very low-risk to apply and all users are urged to apply security updates.
- "Recommended Updates (hardy-updates)". Updates for serious bugs in Ubuntu packaging that do not affect the security of the system.
- "Pre-released Updates (hardy-proposed)". The testing area for updates. This repository is recommended only to those interested in helping to test updates and provide feedback.
- "Unsupported Updates (hardy-backports)". As the name states, these are unsupported versions of future packages which are still in development. Packages may contain new features, may introduce new interfaces, and have not been sufficiently tested to be included in the 'proposed' repository.
For more information on backports, visit UbuntuBackports
This section allows the user to set the frequency and manner of updates. If the 'Check for updates' box is not selected no other options in this section may be set.
Allows users to upgrade to new versions of Ubuntu.
- "Normal Releases" - Allows an upgrade from one regular release to another, such as from Ubuntu 7.10 (Gutsy Gibbon) to Ubuntu 8.04 (Hardy Heron).
- "Long Term Support Releases Only" - Allows upgrade from Ubuntu 6.06 (Dapper Drake) LTS to Ubuntu 8.04 (Hardy Heron) LTS but not to other distributions which were not designated Long Term Support releases.
If you made any changes don't forget to "Close" and "Reload" so the repositories will be updated.
"Authentication keys" are usually obtained from the maintainer of the software repository. The maintainer will often place a copy of the authentication key on a public key server such as www.keyserver.net. The key can then be retrieved using the command:
gpg --keyserver [name of keyserver] --recv-keys [keyhash]
- In our example above, you would import the maintainer's authentication key as follows:
gpg --keyserver subkeys.pgp.net --recv-keys 1135D466
- Then, add the key to Ubuntu's apt trusted keys database with the following command
gpg --export --armor 1135D466 | sudo apt-key add -
- Note there's a dash at the end of the line
For more on apt and authentication keys, see SecureApt.
The Statistics tab is provided for those users who wish to provide data anonymously to the Ubuntu project. Information collected and reported include such items as application installation and usage.
Integration with Add/Remove
Add/Remove is a GUI-based method to add applications. It allows the user to selectively choose the repositories to be searched and then presents a list applications with brief descriptions of each program. From the Ubuntu main menu, select "Add/Remove". Open the "Show" window at the top center of the window. You can make the following choices:
- "All Available Applications" - All enabled repositories are available.
- "All Open Source Applications" - All unrestricted and freely-distributable applications.
- "Supported Applications" - Fully supported Canonical repositories.
- "Third-Party Applications" - Only independent, non-Ubuntu repositories.
- "Installed Applications Only".
If you wish to cancel the changes you made, use the "Revert" button. The panel will restore the repository settings saved during the last update.
Exploring the Repositories
There are several gui-based methods you can use to explore the repositories. One is to open Synaptic and click on the Origin button. This will display a repository list in the window above the button. The list will contain all the repositories enabled in your sources.list. To the right will be the packages available via download (white boxes) and currently installed packages (green boxes). There are two images of the main Synaptic page below. The first, on the left, shows the results of selecting local/main. Local packages are packages stored on the user's computer. The second example, on the right, displays the results of selecting the Ubuntu main online repository. If you highlight a package and select Properties in the top menu you may be able to determine the repository origin in the Section: area. You can check the information in Section: for repository information. If it is listed, the repository will be listed in parentheses. If there is more than one repository in the sources.list with that ending (for instance nonfree) you will have to look at the Maintainer area to try to determine which specific repository is the source.] Another method to find a package's repository is to visit . The search box is an easy method to quickly locate a package maintained by the Ubuntu team. Several input selections are available to help the user refine the search. For packages not included in the supported Ubuntu repositories, an internet search using the package name and "deb" may be successful.
- Managing Software Repositories from the Command Line
- Managing Software Repositories in Kubuntu
- Adding extra repositories
- Adding, Removing and Updating Applications
- The Debian Apt User Manual
- man pages
- Personal repositories
- Launchpad - Installing Software from a PPA