The repository is ... Installing programs from the repository and adding new repositories

All kinds of programs or updates, which are currently used in Ubuntu, are installed exclusively from the repositories. However, many users do not even know what it is and what its main purpose is.

What it is?

The repository is a special place from which the user of the Ubunty operating system can install all kinds of updates or programs. If you used to use Mac and Windows operating systems before, you probably already got used to the fact that the software is one or several installation files that are provided to a user on certain media or can be downloaded over the Internet. For the Ubuntu operating system, this option is also provided for software distribution, but it refers more to specialized closed or proprietary programs.

The repository is the place where most of the Ubuntu software is contained, which is packaged into specialized .deb files with the content of the required libraries in them. Such files can often be found on the Internet or on any portable media, even on a CD, from which the operating system is installed.

Repository as a universal repository of Ubuntu

However, seeing such files, many users may not even know what the repository is. It is a specialized storage server on which such files reside. In other words, repositories can be called a kind of source of applications, since users from their computers connect to them via the Network or the Internet using specialized utilities, after which they can see what packages are already on the computer and which ones can be installed. It is worth noting that the majority of utilities support the procedure for simple keyword searches, and can split packets into several groups by category.

The use of the "repository" bundle is the ability to use quite a bit of simplicity, and at the same time a centralized method of installing or removing various software, and also for users, it is much easier to upload various updates. In a freshly installed operating system, the required repositories can already be located, but no one prohibits the use of third-party data stores.

Ubuntu repositories contain a huge number of very different software, so often there is nothing difficult in finding the utility you are interested in. Of course, you can just download some .deb package from the Internet or even try to compile the program yourself from the sources, but you should understand that this option is more labor-intensive and does not always ultimately prove to be effective.

How do I search for and install different programs?

Initially, using Ubuntu repositories, you should proceed from the fact that there is a definite task that must be solved with the help of the utility, but you may not even know whether it exists and how it is called. However, it is likely that you know the equivalent programs that are used in other operating systems.

Using some Internet search engine, you find interesting options for the desired program, for example, typing the name of a similar utility in Windows, but adding to the query "for Ubuntu." In most cases, the search engine will give you several names of programs, while it is worth noting the fact that they can be represented in a fairly large number, but you can choose the most optimal from the reviews of those users who have already used it. Almost every modern utility has its own page on the Internet, where it will be possible to get acquainted with additional characteristics or to view screenshots.

Where to download the program?

After you have decided on the name of the program you are interested in, you will need to launch the Ubuntu application center, and then find it in an accessible list. Most likely, you will be able to find it and install it in a fairly short time. In addition, it is likely that developers have their own repositories for iOS 7 or other operating systems. In most cases, these repositories contain the most recent versions of the program you are interested in, so if you are interested in maximum productivity, you should carefully inspect the site, and use the search.

Only if you can not find the right program using repositories for iOS 7 or other OS, you should try other installation options. Often it happens that those versions of the software that are in the repositories are outdated versions, but in fact there are often situations where they are better integrated into Ubuntu, and in certain situations also differ more stable work .

Sections

In Ubuntu, the best repositories are divided into four sections, called components, and are intended to reflect the page both in the license and in the level of support available to the user. Packages are divided into components as follows:

• Main is absolutely free software that is supported by Canonical.
• Restricter - proprietary software that includes mostly different device drivers. All utilities are also supported by Canonical.
• Universe is also free software that is not officially supported by Canonical, but is controlled by the user community of the operating system.
• Multiverse - proprietary software that does not have the support of Canonical.

Types of repositories

There are also 5 main repositories:

• Release - packages that were released at the time of release.
• Release-security - packages in which there are some critical security updates.
• Release-updates - packages containing the system updates, including also various more modern versions of the software that were released after the official release.
• Release-backports are all possible backports belonging to new versions of certain software, which is available only in unstable versions of the operating system Ubuntu.
• Partner - repository, which contains various software companies that are partners Canonical.

It is worth noting that, in addition to official, there are also other repositories for iOS 8 and other operating systems. They can be created by the authors of certain utilities, as well as by people who simply decided to compile a full package from the source code, and then publish it publicly for other users.

Adding via Launchpad

If you do not know how to add a repository, Launchpad, which provides the ability to create PPA-repositories, will help you in this. These stores are relatively small packages, in which the owner adds various sources, and users are provided with a full-fledged deb-document.

How to connect?

If a person does not find the utility he is interested in, he can figure out how to add the repository, then load the necessary software into it. After all, it often happens that Ubuntu repositories simply do not have various utilities that can be used to solve certain tasks. It is for this reason that there is a sufficiently large number of third-party repositories, when connecting which you can access the necessary software. This can be done both with the use of a graphical interface, and through the console.

It should be noted immediately that in some repositories, in addition to the packages that you need, there can be also various experimental assemblies of different software, including also kernels that contain Linux repositories. Since the version of such packages is mostly higher in the majority of cases than those used by you, "Update Manager" can try to update the system on its own. It will do this via free repositories, which can damage your system. For this reason, you should in any case carefully read the descriptions of the connected storage, as well as the information that is in the "Update Manager".

Using the graphical interface

In this case, the repositories for iOS 8 and other OSs are connected as follows:

1. The Ubuntu application center opens.
2. Next, go to the "Edit" / "Sources of applications".
3. In the new window, select the "Other Software" tab, and then click on the "Add" button.
4. In the new window we fill in the field "ART line:", press the "Add source" button.
5. Now the source is added and enabled, you can close the window.

Since you have connected a new software source, you will need to update the information about the packages. In most cases, after connecting, a window appears in which the user is offered to update this data. In the window you just need to click on the "Update" button.

After you have updated all the information about the packages, the "Application Sources" window will be closed, and most likely you will get an error stating that the application source is unsigned. However, you can install the utilities that are of interest to you, which are contained in the repository you connected, using standard tools. To eliminate the error of the unsigned repository, you should deal with the protection system already.

Using the console

This option is the most optimal of all existing methods. It is best to add a local repository or other types of repositories using the console. This is done quite simply, because the repository is added with just one command, such as, for example: sudo apt-add-repository ppa: ripps818 / coreavc.

If necessary, you can also use the console to delete the repository.

Protection system

Since in most cases repositories are located on the Internet, there is a possibility that attackers can substitute the repository for their own, which contains various modified packages. Thus, installing the modified software on your computer, the user can put his system under real threat. However, many repositories provide protection against spoofing. This protection option is implemented by comparing the digital signatures of the client and the repository. In the event that the store has a digital signature, there is a key on the user's computer that is open for this repository.

In Ubuntu, the standard storage is located on the installation disks. If there are multiple connected repositories on the user's computer at the same time, trusted repositories are preferred.

How to add a key?

By connecting a storage that is protected by a digital signature, you will need to download a specialized public key that must be added to the system. Quite often, for downloading, you can provide a package that is available for installation, which completely independently will register the key of the repository. If you download the key directly from the site of the repository, then in this case you will be provided with a regular file with the extension .gpg, .key or some other. Add this file to the system using the console command sudo apt-key add repo.key, but instead of .key you specify the repository key that you received.

Adding a key through the server

The best option is to add a key through a dedicated server that is under protection. Quite often, when it comes to a key, its alphanumeric identifier is given, which at first glance may seem completely incomprehensible to the user, but this is a unique name. These keys are located on special servers, where anyone can get them.