Home > Articles > Operating Systems, Server > Linux/UNIX/Open Source

This chapter is from the book

Making Your Own Packages

The power of a package management system is that you can track dependencies and conflicts, do automatic upgrades, and keep track of every file on the system and which piece of software it belongs to. Installing through packages is much easier than if one simply downloads and builds from scratch, but the package management system truly shines when it comes time to uninstall or upgrade. If you've installed from source, files may be in any number of places on your file system. If you've installed from a package, removing your package will be as simple as apt-get remove.

As a result, many responsible system administrators find it very convenient to ensure that all software on their systems is installed from packages. That sounds great, but sometimes a piece of software you want—or a version of a piece of software that you want—isn't packaged or isn't built for the version of Ubuntu that you are running. The result is that you'll need to build, in one way or another, your own packages. The rest of this chapter gives a brief overview of this process and provides a starting spot for the system administrator who wants to move beyond simply consuming packages and become a producer.

Rebuilding Packages

As I hinted earlier in this chapter, many users want to rebuild existing packages as part of backporting a version of a piece of software available in one version of Ubuntu—or Debian—to a current one. Sometimes, if an ABI has changed, a piece of software won't work on a version of Ubuntu simply because it was compiled against a set of libraries that are no longer present. This is the easiest possible case to fix because adjusting for it is simply a matter of downloading the source and rebuilding it against the new version of the libraries. This section will cover doing exactly this.

Doing so will first require a source package. The source package, as you may remember from earlier in this chapter, consists of a DSC file and at least one other file. These can be downloaded as normal files from http://packages.ubuntu.com and unpacked with dpkg-source -x filename .dsc , or they can be installed automatically by using the apt-get source package command.

If one wanted to download and compile a package from a particular distribution—as is often the case—one could specify this explicitly with the -t option, which, behind the scenes, sets the default PIN for the distribution at a very high priority (990 in fact) by running (for example)

$ apt-get -t jaunty source --compile most

This would download and unpack the version of most source packages from Jaunty—assuming, of course, that the necessary deb-src line was included in /etc/apt/sources.list. The unpacked source code will be in a subdirectory of the current directory made up of the package name and version. In this case, the directory would be called most-5.0.0a since 5.0.0.a is the version of most that I've downloaded. By adding a --compile flag to the apt-get invocation above, the binary packages will also be built automatically—even if the program is in an interpreted language and there is no actual compiling taking place. If one does not use the compile flag, it can be invoked afterward in several ways. One of the simplest is by changing into the directory and then running dpkg-buildpackage like this:

$ cd most-5.0.0a
$ dpkg-buildpackage -us -uc -rfakeroot

This command will create an unsigned package (the -us and the -uc refer to unsigned source and unsigned changelog files) without needing root privileges (fakeroot is a program that allows packages to be built without root). Of course, the package may also require build dependencies that are not installed by running a command in the following form:

# apt-get -t jaunty build-dep most

The build-dep subcommand to apt-get automates the process of installing all software necessary to build a given package. Running it is a frequent first step in rebuilding any package for the first time when that package is from an installed repository.

When the software in question is successfully rebuilt, the directory will contain a set of binary packages for this source package that end with .deb in the directory where it is run. In this case, the single binary package created was called most 5.0.0a-1 i386.deb. The -1 following the version number of the software refers to the version of the package and could be incremented each time we made a new version of the package. The i386 in this case simply refers to the architecture for which the binary package was built. In this case, I built it on an Intel machine. For many users, this will say amd64, which is an increasingly popular architecture. For most interpreted programs that will run on any architectures, this will say all.

New Upstream Versions

New upstream versions of packages are slightly more complicated than simply rebuilding an existing package with no modifications. Installing the package devscripts provides the user with a program called uupdate which helps with this process. To use uupdate, a user must first download the source package with a command like apt-get source most. Leave off the compile option for the moment, and then download the new upstream version tarball. There is no reason to unpack it at this point and, optionally, rename it into name-version.tar.gz format. Changing into the directory of the old package's source and running uupdate with the new upstream tarball as the argument will usually do the trick:

$ cd most-5.0.0a $ uupdate ../most-5.0.1.tar.gz

Usually, uupdate then deduces the version number from the upstream tarball and applies all the changes made to the old version to the new upstream source. If uupdate can't decode the version number, the new version number can be specified as a second argument to the command.

The output from uupdate should explain the process that it follows and will end with a description of the location of the new modified source. In this case, changing to ../most-5.0.1 will put me in the new "updated" package directory. It's a good idea to look around first to make sure that things worked well. Especially it is worth checking the debian/ subdirectory and paying attention to both the control file and the changelog file in that directory, the latter of which will have been updated automatically but will probably need a little bit of tweaking. The stanza at the top will include information on the new release and can be updated or tweaked to reflect changes that you made to the file. Once you are satisfied, you can build the package with dpkg-buildpackage in the way described in the previous section.

Building Packages from Scratch

Building packages from scratch is much more complicated and involves getting to know quite a bit about the internals of Debian packages. As a result, it is outside the scope of this chapter. As a hint, new packages can be most easily created using the package dh-make, which installs the program dh_make, which is invoked from inside the unpacked source tarball from the upstream developer. For many simple packages, dh_make does most of the hard work of creating workable packages.

Much more information on creating packages for Ubuntu can be found in the Ubuntu packaging guide, which goes in depth into the process of creating packages from scratch: https://wiki.ubuntu.com/PackagingGuide.

It is worth noting one important caveat to the Ubuntu documentation: The packaging guide is focused on creating packages that are designed to be uploaded to Ubuntu. If you are creating packages that will be installed only on your own machine, the potential for harm is much less, and many of the guidelines in the packaging guide can be treated as just that—especially in the first version of a package. The difference is between workable packages and policy-compliant packages.

If you are going to proceed and create packages to be shared with others or perhaps even uploaded into the Ubuntu repositories eventually, it is a very good idea to follow the instructions in the packaging guidelines carefully and to use programs like lintian, which will check your packages for many common errors—useful steps in any situation. If you just want things to work, a brief trip through the guide and use of dh_make will probably put you in good enough shape to get by.

Hosting Your Own Packages

A final step in the creation of your packages will be hosting them in a place where others can get them in the simple "add a line to your source.list file" sort of manner to which I have referred throughout this chapter. There are several different ways to do this. The easiest one and the one most commonly practiced in the Ubuntu world is to use Launchpad—the infrastructure built by Canonical and used extensively in Ubuntu's own development—to host what's called a Personal Package Archives (PPA).

With a PPA, a developer can simply upload a source package to Launchpad and the package will then be built on a variety of architectures and posted into a PPA. PPAs work exactly the same way that developing for Ubuntu does, so using them is a great preview of what you will experience if you decide to eventually upload your software in Ubuntu and get involved on the development side of things. Earlier, when I showed how to add Bazaar packages to the list of packages, I entered the list of the Bazaar PPAs. More information on PPAs is available at the following URLs: https://help.launchpad.net/Packaging/PPA and https://launchpad.net/ubuntu/+ppas.

Alternatively, you can host your own repository on your own server with any of several different tools. Although the classic tool for running these is a package called apt-ftparchive, the newer project reprepro is probably a better fit. Installing the package with that name and looking in the documentation is a good way to get started.

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020