BuildToolsDebian < LCFG

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---+!! Using the LCFG Build Tools on Debian

Support for building Debian packages with the LCFG Build Tools was added in version =0.9.18= which was released on Friday 18th January 2019.

For useful information on Debian packaging see DebianPackaging

%TOC%

---++ Creating Debian packaging metadata

To build a project as a Debian package there needs to be a =debian= sub-directory which contains all the necessary metadata. This is the equivalent of the RPM specfile with which people will already be familar. The biggest difference from a specfile being that with Debian packages there are separate files for each aspect of packaging (e.g. the build/install process, controlling which files appear in a package, handling package scripts).

A tool to generate the necessary Debian package metadata is provided. This uses the lcfg metadata (stored in the =lcfg.yml= file) and examines the contents of the project directory, it does NOT make any attempt to parse the specfile. What is generated is intended to be a good starting point, it should be adequate for a standard LCFG component package or a simple project with a single package. For more complex projects with various sub-packages the Debian metadata will need to be editted manually.

The metadata is generated using the =gendeb= command like this:

<verbatim>
% lcfg-reltool gendeb
No version-control information in the LCFG metafile for this project.
Auto-detected that the SVN module should be used.
LCFG: Creating debian/compat metadata file
LCFG: Creating debian/control metadata file
LCFG: Creating debian/copyright metadata file
LCFG: Creating debian/docs metadata file
LCFG: Creating debian/postinst metadata file
LCFG: Creating debian/postrm metadata file
LCFG: Creating debian/prerm metadata file
LCFG: Creating debian/rules metadata file
LCFG: Creating debian/lcfg-file.service metadata file
LCFG: Creating debian/source/format metadata file
LCFG: Creating debian directory 'debian'
LCFG: Please review the debian directory for this project
</verbatim>

The tool attempts to add all the new files to the version-control system. It's a good idea to review what has changed before committing:

<verbatim>
% svn status
A       debian
A       debian/compat
A       debian/control
A       debian/copyright
A       debian/docs
A       debian/lcfg-file.service
A       debian/postinst
A       debian/postrm
A       debian/prerm
A       debian/rules
A       debian/source
A       debian/source/format
</verbatim>

Anything in the =debian= sub-directory which has a =?= (question mark) prefix will need adding if it is required.

Once you are happy with the changes then they should be committed and a new release should be tagged:

<verbatim>
% svn commit -m "Added debian packaging metadata" debian
% lcfg-reltool minor
</verbatim>

Once the =debian= sub-directory exists the behaviour of the LCFG build tools will be changed. For example, whenever a release is tagged the =debian/changelog= file will be updated and Debian source files will be generated whenever commands such as =pack= and =devpack= are used (which are called be =rpm= and =devrpm=).

---++ Building Debian Packages Manually

When the source for a project is packed (e.g. as part of calling =pack=, =devpack=, =rpm= or =devrpm=) the Debian source files will be generated. This avoids bootstrapping issues by making it possible to pack the source on a non-Debian machine and then copy the files over to a Debian machine for building the binary packages. This can be done like this:

<verbatim>
% cd lcfg-example
% lcfg-reltool pack
No version-control information in the LCFG metafile for this project.
Auto-detected that the SVN module should be used.
LCFG: Successfully exported the source tree.
LCFG: Successfully generated cmake files.
Successfully generated metadata files for RPM
LCFG: Successfully generated source tar file.
LCFG: Tar file is: /afs/inf.ed.ac.uk/user/s/squinney/lcfgbuild/lcfg-example-1.2.40/lcfg-example-1.2.40.tar.gz
LCFG: Debian Tar file is: /afs/inf.ed.ac.uk/user/s/squinney/lcfgbuild/lcfg-example-1.2.40/lcfg-example_1.2.40-1.debian.tar.gz
LCFG: Debian DSC file is: /afs/inf.ed.ac.uk/user/s/squinney/lcfgbuild/lcfg-example-1.2.40/lcfg-example_1.2.40-1.dsc
Successfully generated metadata files for Debian
</verbatim>

The output shows that this generated 3 files which are needed for building a Debian package: =lcfg-example-1.2.40.tar.gz=, =lcfg-example_1.2.40-1.debian.tar.gz= and =lcfg-example_1.2.40-1.dsc=

These are:

   $ Project source : This is the =.orig.tar.gz= file, it contains all the source code for your project, it will NOT contain the =debian= sub-directory.
   $ Debian metadata : This is the =.debian.tar.gz= file, it contains the =debian= sub-directory.
   $ Debian source control : This is the =.dsc= file, it is used to control the build process.

Note that Debian expects a *very* specific naming style for these files. The project name will always be lower-cased and there must be an =_= (underscore) between the name and version strings.

Assuming those 3 files have already been copied over to the target machine, manually building a Debian package can be done something like this:

<verbatim>
% dpkg-source --extract lcfg-example_1.2.40-1.dsc
dpkg-source: warning: extracting unsigned source package (lcfg-example_1.2.40-1.dsc)
dpkg-source: info: extracting lcfg-example in lcfg-example-1.2.40
dpkg-source: info: unpacking lcfg-example_1.2.40.orig.tar.gz
dpkg-source: info: unpacking lcfg-example_1.2.40-1.debian.tar.gz
% cd lcfg-example-1.2.40
% debuild --no-sign
% cd ..
</verbatim>

If all has gone well you now have a Debian binary package named like =lcfg-example_1.2.40-1_all.deb=. There are other output files, one which is quite useful is the =.build= file which contains a log of the whole build process, that can be useful when trying to locate the cause of a build failure.

---++ Building Debian Packages using Build Tools

If you have the LCFG build tools installed on a Debian machine then the binary packages can be generated simply like this:

<verbatim>
% cd lcfg-example
% lcfg-reltool deb
</verbatim>

Or

<verbatim>
% cd lcfg-example
% lcfg-reltool devdeb
</verbatim>

These work in a similar way to the familiar =rpm= and =devrpm= tools that are used for building RPMs.


-- %USERSIG{squinney - 2019-01-18}%
Topic revision: r2 - 2019-02-06 - squinney