SME Server:Documentation:Developers Manual:Chapter14

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The SME Server development environment

Configuring your development environment

The SME Server source code is checked into CVS at SourceForge. The project has a SourceForge page at https://sourceforge.net/projects/smeserver/. All packages are built using mezzanine, and an overview of mezzanine is provided here: https://wiki.caosity.org/tiki-index.php?page=Package+Maintenance

Reminder: The SME Server is released under the GPL

The SME Server source code is released under the GPL. You must release the source code to all modifications. If you make improvements, please raise a bug and attach a patch so the change can be discussed and pulled back into the base for everyone to share.

Do I need a SourceForge account?

Not really. Only developers who are going to put patches back into CVS and build new packages need SourceForge CVS access. The sources are freely available and patches are gratefully received. Just follow the instructions in this section and attach the patch(es) to the Bugzilla entry, explaining why the change should be made.

Add some useful aliases

Mezzanine needs to know to use the SourceForge CVS repository in order to checkout/get or import a package. Once a package is checked out from SourceForge, mezzanine/CVS will remember where it came from and check it back into the same CVS repository. You should not set the CVSROOT environment variable as it makes it too easy to accidentally import code into the wrong CVS repository when working with multiple repositories.

Add the following lines to ~/.bashrc (or a file such as /etc/profile.d/smebuild.sh to configure it for all users on this machine): 

export CVS_RSH=ssh # tell CVS to use ssh
 
 # DO NOT set CVSROOT
 sf_cvsroot=smeserver.cvs.sourceforge.net:/cvsroot/smeserver
 sf_cvsroot_anon=:pserver:anonymous@smeserver.cvs.sourceforge.net:/cvsroot/smeserver
 
 alias mzgetsf="mzget --dir $sf_cvsroot"
 alias mzimportsf="mzimport --dir $sf_cvsroot"
 
 alias mzgetsf_anon="mzget --dir $sf_cvsroot_anon"

You can now use the mzgetsf_anon (or msgetsf if you have a developer account) to retrieve a package from SourceForge. If you use mzget, you will get an error message to remind you that CVSROOT has not been set, and should not be set. Note that you can use the other mezzanine commands, such as mzclean and mzsync normally as the CVS repository is already known. 

[gordonr@smebuild tmp]$ mzget smeserver-yum
cvs checkout: No CVSROOT specified!  Please use the `-d' option
cvs [checkout aborted]: or set the CVSROOT environment variable.
An unknown error must have occured, because the command returned 256

Create your work area

It is a good idea to perform all of your checkouts in a standard directory hierarchy. This makes it easier to move around between the packages. On a shared build server, it also makes it easier for people to recover your work if required (for example when you are on holidays). If you want to use filesharing to edit files from a networked PC, you might like to use ~/home/smeserver/. On a shared build server, you might even use something like /builds/users/$LOGNAME/smeserver/ so the files are not in your home directory and are accessible to all developers.

Note: Reminder: All files must be checked in using Unix text format. 

[gordonr@smebuild ~]$ mkdir ~/smeserver

[gordonr@smebuild ~]$ cd ~/smeserver

Modifying an SME Server package

Raise a Bugzilla entry

Before you make any changes to a package, you need to have a Bugzilla entry which specifies the problem and preferably proposes a fix. Raising the bug before you do the work allows others to comment on the proposed approach and can save significant time when you go to submit the changes. The change should also be approved by the Development Manager if it is meant for near-term release. You will need the Bugzilla bugid when you check in the changes.

All changes must have an associated Bugzilla entry. The bug tracker is here: http://www.contribs.org/bugzilla/

If a relevant bug does not exist, raise one. If the bug exists, assign it to yourself to show that you are working on it:

For this exercise, let's look at bug 1174 "yum-import-keys should not import duplicates" http://www.contribs.org/bugzilla/show_bug.cgi?id=1174.

Choose the package(s) to modify

If you are modifying an existing file, the simplest way to determine the package is to install the relevant version and run rpm -qf on the file to be modified: 

[gordonr@smebuild actions]$ rpm -qf /etc/e-smith/events/actions/yum-import-keys
smeserver-yum-1.1.2-05

and so, we want to modify the smeserver-yum package.

Note: You can view a complete list of the packages checked into SourceForge CVS http://smeserver.cvs.sourceforge.net/smeserver/. On rare occasions, the sources of particular packages may be slightly out of date as there is a small delay (typically only a few hours) between changes to the developer CVS and the anonymous CVS. In practice, this rarely matters and at worst it requires a merging of your changes with any other recent changes to the package.

All packages on the SME Server ISO/CD must be checked into SourceForge CVS. The only exceptions are packages which come from the following upstream repositories: CentOS and dag.

mzgetsf_anon: SourceForge anonymous CVS checkout

You can now retrieve one of the packages from SourceForge. In this case, we want to modify the smeserver-yum package, so let's retrieve it from SourceForge: 

[gordonr@smebuild smeserver]$ mzgetsf_anon smeserver-yum
U smeserver-yum/ChangeLog
U smeserver-yum/F/smeserver-yum.spec
U smeserver-yum/P/smeserver-yum-1.2.0-DisplayStatus.patch
U smeserver-yum/P/smeserver-yum-1.2.0-DisplayStatus.patch2
U smeserver-yum/P/smeserver-yum-1.2.0-ModifyUpdateDBs.patch
U smeserver-yum/S/smeserver-yum-1.2.0.tar.gz

Note: Use mzgetsf if you have a SME Server developer account.

Mezzanine package hierarchy

[gordonr@smebuild smeserver]$ cd smeserver-yum/

[gordonr@smebuild smeserver-yum]$ ls
ChangeLog  CVS  F  P  S  smeserver-yum

If you examine the checked out package, you will see the following directories:

  • The SME Server project does not use the ChangeLog file as we maintain all of our changes in the %changelog section of the SPEC file.
  • The CVS directory contains CVS state information, such as the location of the CVS repository: [gordonr@smebuild smeserver-yum]$ ls CVS
Entries  Entries.Log  Repository  Root
  • The F directory contains the SPEC for this package: [gordonr@smebuild smeserver-yum]$ ls F
CVS  smeserver-yum.spec
  • The P directory contains any patches which are required to update the source in the tarball(s) to the current version: [gordonr@smebuild smeserver-yum]$ ls P
CVS
smeserver-yum-1.2.0-DisplayStatus.patch
smeserver-yum-1.2.0-DisplayStatus.patch2
smeserver-yum-1.2.0-ModifyUpdateDBs.patch
  • The S directory contains the source tarball(s): [gordonr@smebuild smeserver-yum]$ ls S
CVS  smeserver-yum-1.2.0.tar.gz

Note: The smeserver-yum subdirectory is a leftover from an incorrect package import. It can be ignored and will be removed when maintenance is next performed on the CVS repository.

mzclean: Clean out modified files

Before making changes to a package, you should ensure that you have a clean copy of the latest sources. Remember - other people may also be working on the package and making changes in SourceForge. You can perform a "merge" when you check in your changes, but it is easiest to start with an up-to-date copy. It is even possible that someone else has already fixed the bug you are working on! 

[gordonr@smebuild smeserver-yum]$ mzclean
Cleaning and resyncing smeserver-yum, please wait....
Removing work....
Cleanup of smeserver-yum complete.

[gordonr@smebuild smeserver-yum]$ ls
ChangeLog  CVS  F  P  S

Tip: Ensure that you have copied any modified files out of your work tree prior to runing mzclean.

Note that the stray smeserver-yum subdirectory has been removed.

mzprep: Build working tree

The mzprep command runs rpmbuild -bp on your SPEC file, sources and patches to generate a working tree. You can make changes in the working tree and use mezzanine to generate the patches between the previous version and your new files. 

[gordonr@smebuild smeserver-yum]$ mzprep
Creating working directory /home/e-smith/files/users/gordonr/tmp/sf/smeserver-yum/work....
You may now chdir to work to make changes.
Use "mzpatch -n <patch_name>" to generate a patch when done.

[gordonr@smebuild smeserver-yum]$ ls
ChangeLog  CVS  F  P  S  work

The only obvious change is the creation of a work/ subdirectory. Let's have a look in there. Under the work/ directory is smeserver-yum-1.2.0/ which contains the patched sources for this version of smeserver-yum. 

[gordonr@smebuild smeserver-yum]$ ls work/
smeserver-yum-1.2.0

Under smeserver-yum-1.2.0/ are the createlinks script, the root hierarchy and a few generated files, explained below. 

[gordonr@smebuild smeserver-yum]$ ls work/smeserver-yum-1.2.0/
createlinks      debugsources.list  smeserver-yum-1.1.2-26-filelist
debugfiles.list  root

SME Server package directory layout

Table 14-1. SME Server package directory layout

Directory/File Description createlinks Builds action, panel and initscript links.
po Package translations, if gettext is used.
root The top-level directory of the package, which will be the / directory of the installed system. So, root/usr/lib/perl5/site_perl becomes /usr/lib/perl5/site_perl on the installed system. Note that the somewhat confusing root/root is the /root directory of the installed system.
update-po Helper script to generate translation binary files, if gettext is used.
debugsources.list debugfiles.list Generated by RPM build - lists this files which are built with debug flags
smeserver-yum-1.1.2-26-filelist Generated by RPM build - lists the files to be packaged, and their permissions and ownership

The root directory hierarchy

The work/smeserver-yum-1.2.0/root/ hierarchy contains the files which will be installed on the target machine. 

[gordonr@smebuild smeserver-yum]$ ls work/smeserver-yum-1.2.0/root/
etc  sbin  service  usr  var

Modifying a file

OK - now we can actually make a change. We want to modify the file which will be installed as /etc/e-smith/events/actions/yum-import-keys, so the actual file we need to modify is: work/smeserver-yum-1.2.0/root/etc/e-smith/events/actions/yum-import-keys.

Use your favourite editor (in Unix text mode) to modify the file, adding a comment where the change needs to be made. Here's a diff showing such a comment: 

[gordonr@smebuild tmp]$ diff -u yum-import-keys.orig yum-import-keys
--- yum-import-keys.orig        2006-05-22 16:28:51.734609534 +1000
+++ yum-import-keys     2006-05-22 16:28:39.006814950 +1000
@@ -30,6 +30,7 @@
 for my $key ( grep {!/^\./} readdir(DIR) )
 {
     warn "Importing key $key\n";
+    # TODO: Skip keys which have previously been imported

     system("rpm", "--import", $key) == 0 or
        warn "Couldn't rpm --import $key\n";

mzpatch: Create a patch

Mezzanine automates the creation of patches through the mzpatch command.

Note: Always run mzpatch from the top-level directory of your package (e.g. ~/smeserver/smeserver-yum/). 

[gordonr@smebuild actions]$ cd ~/smeserver/smeserver-yum/

[gordonr@smebuild smeserver-yum]$ ls P
CVS
smeserver-yum-1.2.0-DisplayStatus.patch
smeserver-yum-1.2.0-DisplayStatus.patch2
smeserver-yum-1.2.0-ModifyUpdateDBs.patch

You will see from the listing above that the patches should be named package-version-patchname.patch. You should also ensure that the patch name you are about to choose doesn't already exist, or you may overwrite an older version of the patch. 

[gordonr@smebuild smeserver-yum]$ mzpatch -n smeserver-yum-1.2.0-ImportKeysComment.patch
Creating working directory /home/e-smith/files/users/gordonr/tmp/sf/smeserver-yum/work....
Created P/smeserver-yum-1.2.0-ImportKeysComment.patch (11 lines).
cvs [server aborted]: "add" requires write access to the repository
You do not have write access to the master repository.
srctool:  Error:  Addition of P/smeserver-yum-1.2.0-ImportKeysComment.patch failed.
[gordonr@smebuild smeserver-yum]$ ls P
CVS
smeserver-yum-1.2.0-DisplayStatus.patch
smeserver-yum-1.2.0-DisplayStatus.patch2
smeserver-yum-1.2.0-ImportKeysComment.patch
smeserver-yum-1.2.0-ModifyUpdateDBs.patch

Mezzanine has created the patch, but it has not committed it to CVS. This allows you to revise the patch until it works, prior to committing it. If you do not have a developer account you will get an error when mezzanine attempts to reserve the patch name in CVS, but the patch will still be created in the P directory.

The patch looks quite similar to the one we saw previously, except for the pathname to the modified file: 

[gordonr@smebuild smeserver-yum]$ cat P/smeserver-yum-1.2.0-ImportKeysComment.patch
diff -Nur -x '*.orig' -x '*.rej' smeserver-yum-1.2.0/root/etc/e-smith/events/actions/yum-import-keys mezzanine_patched_smeserver-yum-1.2.0/root/etc/e-smith/events/actions/yum-import-keys
--- smeserver-yum-1.2.0/root/etc/e-smith/events/actions/yum-import-keys 2005-09-26 12:30:54.000000000 +1000
+++ mezzanine_patched_smeserver-yum-1.2.0/root/etc/e-smith/events/actions/yum-import-keys       2006-05-22 16:35:57.752811633 +1000
@@ -30,6 +30,7 @@
 for my $key ( grep {!/^\./} readdir(DIR) )
 {
     warn "Importing key $key\n";
+    # TODO: Skip keys which have previously been imported

     system("rpm", "--import", $key) == 0 or
        warn "Couldn't rpm --import $key\n";

Building a new package, with the patch

The next step is to change the package SPEC file so that the patch is applied.

Update the Release tag

The first change you should make is to update the "Release" tag in the SPEC file. You should do this by appending your initials and sequence number to the Release number. In most SME Server SPEC files, the Release number is set via the release macro, and so you should set it there. 

Summary: YUM, an rpm updater
%define name smeserver-yum
Name: %{name}
%define version 1.2.0
- %define release 05
+ %define release 05ff01

Please just append your initials and a sequence number to the release tag. Do not change the package name (e.g. to smeserver-yum-fred) or the version number. This policy makes it obvious that your update is a patch based on smeserver-yum-1.2.0-05.

If a change has been approved by the Development Manager, it is given an official version/release number (e.g. smeserver-yum-1.2.0-06). Always tag unofficial changes with your initials and sequence number.

If an upstream (e.g. CentOS) package needs to be patched and it is not possible to wait for the patch to come from the upstream source, the release number should be modified with the special tag sme and a sequence number (e.g. clamav-0.88.2-1sme01). The sme tag is reserved for changes approved by the Development Manager.

Add a changelog entry

The SME Server project maintains history of packages changes in the %changelog section of the SPEC file. The changelog entry should be a simple description of the change of behaviour and must include a reference to an SME Server project Bugzilla entry (1174) and the new version number (1.2.0-05ff01): 

%changelog
 + * Mon May 22 2006 Fred Frog <fred@example.com> 1.2.0-05ff01
 + - Initial work on avoiding duplicate RPM keys [SME: 1174]
 
 * Mon May  1 2006 Charlie Brady <charlieb@e-smith.com> 1.2.0-05
 - Remove stray yum.pm.orig file. [SME: 1350]

The first line of the changelog entry shows when the change was made, by whom and notes the new version number. The other lines describe the change and refer to the Bugzilla entry or entries, using the format [SME: 1174] as a shorthand.

Add a patch reference

You now need to tell RPM to retrieve and apply the new patch. This needs to be done in two places, which is annoying, but allows for patches to be carried around, but not applied (e.g. because they are not quite finished). The first change is near the top of the file: 

Patch0: smeserver-yum-1.2.0-DisplayStatus.patch
Patch1: smeserver-yum-1.2.0-ModifyUpdateDBs.patch
Patch2: smeserver-yum-1.2.0-DisplayStatus.patch2
+ Patch3: smeserver-yum-1.2.0-ImportKeysComment.patch

The second change is in the %prep section: 

%prep
%setup
%patch0 -p1
%patch1 -p1
%patch2 -p1
rm root/usr/lib/perl5/site_perl/esmith/FormMagick/Panel/yum.pm.orig
+ %patch3 -p1
mzbuild: Build a new package

With all that done, you should be able to build a new package using mzbuild: 

[gordonr@smebuild smeserver-yum]$ mzbuild

[...]
Executing(%clean): /bin/sh -e /var/tmp/rpm-tmp.35037
+ umask 022
+ cd /home/e-smith/files/users/gordonr/smeserver/smeserver-yum/build.mezz/BUILD
+ cd smeserver-yum-1.2.0
+ /bin/rm -rf /var/tmp/mezzanine-buildroot.18508
+ exit 0
Package build succeeded.  Output files are:

smeserver-yum-1.2.0-05ff01.src.rpm
smeserver-yum-1.2.0-05ff01.noarch.rpm
Check the package

You should now perform some simple checks on the package before installing it for testing.

  • Does the built package have your initials in the release tag? We never want to have two packages with the same name and version number. [gordonr@smebuild smeserver-yum]$ ls *.rpm
smeserver-yum-1.2.0-05ff01.noarch.rpm  smeserver-yum-1.2.0-05ff01.src.rpm
  • Did you update the changelog? It's easy to forget, but vital to do. [gordonr@smebuild smeserver-yum]$ rpm -qp --changelog \ smeserver-yum-1.2.0-05ff01.noarch.rpm | head -8 * Mon May 22 2006 Fred Frog <fred@example.com> 1.2.0-05ff01 - Initial work on avoiding duplicate RPM keys [SME: 1174] * Mon May 01 2006 Charlie Brady <charlieb@e-smith.com> 1.2.0-05 - Remove stray yum.pm.orig file. [SME: 1350]
  • Did you remember to apply the patch? It happens, and leads to head scratching "I knew I made that change". [gordonr@smebuild smeserver-yum]$ mzbuild | grep patch
+ echo 'Patch #0 (smeserver-yum-1.2.0-DisplayStatus.patch):'
Patch #0 (smeserver-yum-1.2.0-DisplayStatus.patch):
+ patch -p1 -s
+ echo 'Patch #1 (smeserver-yum-1.2.0-ModifyUpdateDBs.patch):'
Patch #1 (smeserver-yum-1.2.0-ModifyUpdateDBs.patch):
+ patch -p1 -s
+ echo 'Patch #2 (smeserver-yum-1.2.0-DisplayStatus.patch2):'
Patch #2 (smeserver-yum-1.2.0-DisplayStatus.patch2):
+ patch -p1 -s
+ echo 'Patch #3 (smeserver-yum-1.2.0-ImportKeysComment.patch):'
Patch #3 (smeserver-yum-1.2.0-ImportKeysComment.patch):
+ patch -p1 -s

Test your new package

You should now upgrade your test system: 

[gordonr@sevendev1 tmp]$ sudo rpm -Uvh smeserver-yum-1.2.0-05ff01.noarch.rpm
Preparing...                ########################################### [100%]
   1:smeserver-yum          ########################################### [100%]

and test that you have fixed the bug.

Lather, rinse, repeat

If you haven't fixed the bug, repeat the cycle: make changes, build a new patch, update the release number (e.g. to 05ff02, 05ff03, etc.), build a new package, test. Don't worry about using up release numbers.

Note: Actually fixing bug 1174 is left as an exercise for the reader. Fame and fortune (or at least thanks) await the person who does.

Attach your patch(es) to the bug

You should now attach your patch(es) and SPEC file changes to the appropriate Bugzilla entry. If the change is the simple application of a patch, you do not need to attach the whole SPEC file - just the changelog entry.

Please attach the patch(es) and ensure that they are in Unix text format. Patches make it obvious which sections of code have been changed and attaching them ensures that their formatting is preserved.

SourceForge developer CVS access

If you are going to work on many bugs, or wish to help with the many tasks involved in a release, you should create a SourceForge developer account.

You do not need a SourceForge account in order to do development. You can contribute very effectively by producing patches and attaching them to the Bugzilla entries.

Create a SourceForge account

  • Create a SourceForge user id
  • Contact the Development Manager (or one of the other project admins) listed on the SourceForge project page, detailing the packages you would like to work on
  • The project admin will add you as a developer
  • Upload an SSH2 key to SourceForge, following the SourceForge documentation: https://sourceforge.net/docs/F02/en/#key_posting
  • You will also need to generate another SSH2 key for access to the smebuild build server

mzgetsf: SourceForge developer CVS checkout

Once you have SourceForge CVS access, you can use mzgetsf (instead of mzgetsf_anon) to retrieve the sources. Your copy will be writable and you will be able to put changes back to CVS. When you run mzpatch you should not see an error during the cvs add step. 

[gordonr@smebuild smeserver-yum]$ mzpatch -n smeserver-yum-1.2.0-ImportKeysComment.patch
Creating working directory /home/e-smith/files/users/gordonr/smeserver/smeserver-yum/work....
Created P/smeserver-yum-1.2.0-ImportKeysComment.patch (11 lines).
cvs add: use 'cvs commit' to add this file permanently
Patch added to SCM.  Use 'mzput' to upload to repository.

mzput: Put the changes back to CVS

Instead of attaching the patch to the Bugzilla entry, you will be able to put it back to CVS. Mezzanine normally edits the ChangeLog, but we don't need to do that as we keep the changes in the %changelog section of the SPEC file. The -m option to mzput allows a simple comment to be appended, which is all that is required: 

[gordonr@smebuild smeserver-yum]$ mzput -m 'See changelog'

Build the official package

Official packages have unadorned release tags (e.g. smeserver-yum-1.2.0-05) and must be built on the official build servers. There are three steps involved - build the RPMs (mzbuild), sign the RPMs (rpm --addsign *.rpm) and release the RPMs (release_rpms *.rpm).

mzimportsf: SourceForge package import

If a package has not already been checked into SourceForge CVS, you can use mzimportsf to import it. You should be careful to run this command from a directory which does not contain an imported package or mezzanine may import the package underneath the existing package.

mzmerge: Merge changed source RPM

If a new source RPM has been built without corresponding changes in SourceForge CVS, you can use mzmerge to merge in the changes. This can also be used to merge in changes from a modified upstream package. Care should be exercised with this command, especially if you want to maintain previous patches.

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