Difference between revisions of "StarlingX/MultiOS/Debian"

Latest revision as of 20:43, 31 May 2019

Starling X build in Debian

Scope of the project

This sub-project of Starling X will extend the current Flock services build artifacts structure to support more operating systems apart from the current CentOS OS supported.

The current directory structure is based around the build working with CentOS OS and the current build tooling. The flock services git repositories provide a directory call centos with the spec files to build RPMs distribution packages. In order to support building the flock services packages for new, different OSes is necessary to provide build artifacts where the community can have a place to contribute with build scripts such as control and rules files (for Debian based operating systems). This wiki describes how to build a package from the Starling X project into a Debian base OS

How to build packages in Debian

These are examples to document how to build Debian files

How to build a package that already exists in Debian

This tutorial is based on [1], to begin these are the steps:

• Open your /etc/apt/sources.list file and check if you have one or more lines that start with deb-src.
• Update:

   sudo apt-get update

• In the directory of your preference create a directory to host the source deb packages:

   mkdir -p src/debian/; cd src/debian 

• Install the ackage you want to modify

   sudo apt-get install fdupes

• Install the source code of the package you want to modify

   apt-get source fdupes

• You have now downloaded the 3 files (.dsc, .tar.gz, .diff.gz), composing the: Debian source package
• Once the package is downloaded, you can check the directory where you are, and you'll find that apart from the 3 files that were downloaded you also have a directory, called fdupes-1.50-PR2. This is the unpacked source of the Debian package.
• Every Debian (or Debian derivative) source package includes a debian directory, where all the information related to the Debian build artifacts for the package are stored. Anything that's outside of that directory, is the upstream code, i.e. the original code released by whoever programmed the software.
• This is the directory that the package maintainer has added to the source code to build the package.
• In this directory you'll usually find lots of files related to Debian's version of the program, Debian specific patches, manpages, documentation, and so on
  • rules file is the script file that we will be running in order to build the package.
  • in the patches directory, there are also a number of patches applied by the maintainer
• Get the build dependencies with: sudo apt-get build-dep fdupes
• Rebuild without changes with

   debuild -b -uc -us

• Install this file with:

   sudo dpkg -i ../fdupes_1.50-PR2-3_<your arch>.deb

At this point, you might be wondering what is the difference between:

• • debuild - build a Debian package
  • dpkg-buildpackage - build binary or source packages from sources

The debuild command is a wrapper script of the dpkg-buildpackage command to build the Debian binary package under the proper environment variables.

How to build a package from tar.gz ( simple example )

The big picture for building a single non-native Debian package from the upstream tarball debhello-0.0.tar.gz can be summarized as:

• The maintainer obtains the upstream tarball debhello-0.0.tar.gz and untars its contents to the debhello-0.0 directory.
• The debmake command debianizes the upstream source tree by adding template files only in the debian directory.
  • The debhello_0.0.orig.tar.gz symlink is created pointing to the debhello-0.0.tar.gz file.
  • The maintainer customizes template files.
• The debuild command builds the binary package from the debianized source tree.
  • debhello-0.0-1.debian.tar.xz is created containing the debian directory.

   $ tar -xzmf debhello-0.0.tar.gz
   $ cd debhello-0.0
   $ debmake
       manual customization
   $ debuild

The debmake command is the helper script for the Debian packaging.

• It always sets most of the obvious option states and values to reasonable defaults.
• It generates the upstream tarball and its required symlink if they are missing.
• It doesn’t overwrite the existing configuration files in the debian/ directory.
• It supports the multiarch package.
• It creates good template files such as the debian/copyright file compliant with DEP-5.

After debmake debuild command build the package

Commands to build

Here is a summary of commands similar to the debuild command.

• The debian/rules file defines how the Debian binary package is built.
• The dpkg-buildpackage command is the official command to build the Debian binary package. For normal binary build, it executes roughly:
  • “dpkg-source --before-build” (apply Debian patches, unless they are already applied)
  • “fakeroot debian/rules clean”
  • “dpkg-source --build” (build the Debian source package)
  • “fakeroot debian/rules build”
  • “fakeroot debian/rules binary”
  • “dpkg-genbuildinfo” (generate a *.buildinfo file)
  • “dpkg-genchanges” (generate a *.changes file)
  • “fakeroot debian/rules clean”
  • “dpkg-source --after-build” (unapply Debian patches, if they are applied during --before-build)
  • “debsign” (sign the *.dsc and *.changes files)

• The debuild command is a wrapper script of the dpkg-buildpackage command to build the Debian binary package under the proper environment variables.
• The pdebuild command is a wrapper script to build the Debian binary package under the proper chroot environment with the proper environment variables.
• The git-pbuilder command is another wrapper script to build the Debian binary package under the proper chroot environment with the proper environment variables. This provides an easier command line UI to switch among different build environments.

Example

Here is an example of creating a simple Debian package from a simple C source using the Makefile as its build system.

Structure of directory:

   mkdir debhello-0.0
   ├── Makefile
   └── src
          └── hello.c

Source code:

   $ cat src/hello.c
   #include <stdio.h>
   int main(){
       printf("Hello, world!\n");
       return 0;
   }

Makefile:

   $ cat Makefile
   prefix = /usr/local
   all: src/hello
   src/hello: src/hello.c
       @echo "CFLAGS=$(CFLAGS)" | \
           fold -s -w 70 | \
           sed -e 's/^/# /'
       $(CC) $(CPPFLAGS) $(CFLAGS) $(LDCFLAGS) -o $@ $^
   install: src/hello
       install -D src/hello \
           $(DESTDIR)$(prefix)/bin/hello
   clean:
       -rm -f src/hello
   distclean: clean
   uninstall:
       -rm -f $(DESTDIR)$(prefix)/bin/hello
   .PHONY: all install clean distclean uninstall

Create tarball:

   tar -czf debhello-0.0.tar.gz debhello-0.0/

After that is possible to start with packaging:

   cd debhello-0.0/
   debmake

Adjsut the override_dh_usrlocal:

   cat debian/rules
   #!/usr/bin/make -f
   # You must remove unused comment lines for the released package.
   export DH_VERBOSE = 1
   #export DEB_BUILD_MAINT_OPTIONS = hardening=+all
   export DEB_CFLAGS_MAINT_APPEND  = -Wall -pedantic
   export DEB_LDFLAGS_MAINT_APPEND = -Wl,--as-needed
   %:
       dh $@
   override_dh_usrlocal:
   #override_dh_auto_install:
   #    dh_auto_install -- LIBDIR=/usr/local/lib
   #override_dh_install:
   #    dh_install --list-missing -X.pyc -X.pyo

Build

   dpkg-buildpackage -B

Check that all binaries are installed in DEB

   cd ..
   sudo dpkg -c debhello_0.0-1_amd64.deb
   hello

If you have the DSC file you just need to:

   dpkg-source -x foo_version.dsc

change into the extracted source directory. Then run:

   dpkg-buildpackage -rfakeroot -b

More info at :

debmake-doc

How to build a package from tar.gz ( more complex example )

debmake-complex

Where does the debian repositories live:

Examples:

• GLIBC: https://salsa.debian.org/glibc-team/glibc/tree/sid
• GCC: https://salsa.debian.org/toolchain-team/gcc-cross

Links

   https://wiki.debian.org/BuildingTutorial

How to contribute to the project: Starling X build in Debian

Starling X multi-os packaging is a side github project with examples of Debian rules and control files.

An example of the control, install and rules files can be seen here:

• https://github.com/marcelarosalesj/x.stx-fault/tree/debian/fm-common/debian

Directory layout specification

StarlingX: Define directory layout for MultiOS