Similar to many other distributions, ROSA pays a lot of attention to automation of different maintainers tasks and tries low the «entry barrier» for newbies. One of the problems faced by almost every newbie who wants to build some application for ROSA is creation of spec file to build an RPM package for our distribution. In many cases spec file can be generated automatically — for example, we have corresponding tools for modules of Python, Perl, Ruby, etc.
However, many programs for Linux are developed using comiled languages such as C/C++ and are built using GNU Autotools, CMake and analogues. Up to now, for such programs we only provided spec file templates and recommendations in Packaging Policies. This is normally enough for experienced maintainers, but newbies often experience difficulties with the very first step of spec file development. That’s why we have developed a new tool named spec-gen which is able to automatically generate spec file template on the basis of analysis of tarball with application source code.
The tool is very easy to use — just install spec-gen package in your ROSA installation and launch spec-gen with tarball name as an argument:
$ spec-gen my_tarball-1.0.tar.gz
By mean of -g, -s, -l and -u options you can specify group, summary, license and URL of the package to be created. You can omit these options and populate corresponding fields with data after the spec file is created. The tool try to guess package name and version on the basis of archive name — the guess is that most archives with source code are named in the «<program_name>-<version>» fashion. The tool supports all popular archive formats, but if you need to add support for more formats — feel free to send us a request.
During its work, the tool will look through archive content and check if it contains configure.in, configure.ac, CMakeLists.txt, *.cmake or setup.py files. If the latter file is found then the tool will simply launch python setup.py bdist_rpm5 command and provide your with a spec file created by it. In case when GNU Autotools or CMake files are detected, spec-gen will analyze them and detect which ROSA packages should be installed to build your application — that is, the tool will try to automatically create a list of Buildrequires for your new package.
We recommend to launch spec-gen in the system for which you want to build a package, since it uses information from system repositories about package provides and files by means of urpmq and urpmf programs.
As a result, spec-gen will provide your with a spec file with filled header, list of BuildRequires, %prep, %build and %install sections. Adjustment of the list of files in the %files section, splitting the package to subpackages and other complex tricks should be performed manually. To be sure, one can’t guarantee that generated BuildRequires list is completely correct — it is possible that some dependencies are not mentioned explicitly in build scripts or spec-gen makes a wrong choice among several alternatives. Nevertheless, in most cases the tool works correctly and provides you with a spec file that ca be used to build a package. It is likely that hte only task left to you is adjustment of the %files section.
It is possible that in future we will implement even more automation — for example, we can try to automatically build a package using generated spec file and then automatically adjust the %files section on the basis of build results. Actually there are a lot of possible improvements in this area, and everybody is welcome to provide su with feedback, share ideas and send patches. The source code is available here — https://abf.io/soft/spec-gen-dev.
Finally we are glad to note that the basis of the spec-gen tool was developed by Andrey Soloviev, a student of Higher School of Economics, during his practice in ROSA Company.