[Engine-devel] Jar versions in ovirt-engine

[Juan Hernandez]

On 04/19/2012 04:21 PM, Doron Fediuck wrote:
> On 19/04/12 17:17, Juan Hernandez wrote:
>> On 04/19/2012 04:10 PM, Doron Fediuck wrote:
>>> On 19/04/12 16:53, Juan Hernandez wrote:
>>>> On 04/19/2012 03:22 PM, Doron Fediuck wrote:
>>>>> On 19/04/12 13:26, Juan Hernandez wrote:
>>>>>> On 04/19/2012 12:00 PM, Doron Fediuck wrote:
>>>>>>> On 18/04/12 14:04, Juan Hernandez wrote:
>>>>>>>> On 04/18/2012 09:51 AM, Ofer Schreiber wrote:
>>>>>>>>> Ever wondered why the version of oVirt's first release is 3.0.0_0001?
>>>>>>>>> The answer is simple - We use ovirt-engine jar's version as our "main" release version.
>>>>>>>>>
>>>>>>>>> Personally, I think the current versioning scheme is ugly. Actually, I can't name even one open-source project using "_" in it's version.
>>>>>>>>>
>>>>>>>>> What can we do about it? We have couple of options:
>>>>>>>>> 1. Leave the engine alone, and use a separate versioning scheme (e.g - use just 3.1.0 as the main version for next release)
>>>>>>>>> 2. Remove "_" from engine jars
>>>>>>>>> 3. Do nothing.
>>>>>>>>>
>>>>>>>>> I'd like to hear your thoughts, as well as the reasons to use such an unusual versioning scheme.
>>>>>>>>>
>>>>>>>>> ---
>>>>>>>>> Ofer Schreiber
>>>>>>>>> oVirt Release Manager
>>>>>>>>> _______________________________________________
>>>>>>>>> Arch mailing list
>>>>>>>>> Arch at ovirt.org
>>>>>>>>> http://lists.ovirt.org/mailman/listinfo/arch
>>>>>>>>
>>>>>>>> From my point of view using the 0001 suffix in the names of the jar
>>>>>>>> files is not a big problem, but I agree that using it in the release
>>>>>>>> number is ugly, and it produces issues/discussions during packaging. I
>>>>>>>> vote for option #1: use 3.1.0 for the next main version.
>>>>>>>>
>>>>>>>
>>>>>>> The original versioning scheme was due to a bug in maven2.
>>>>>>>
>>>>>>> Juan, I've read some of the Java packaging concepts, but didn't see
>>>>>>> (or missed) thoughts about modular versioning (ie- artifacts).
>>>>>>>
>>>>>>> Here are the things to consider here;
>>>>>>>
>>>>>>> - Current RPM's are using the version declared in the POM files.
>>>>>>> Should this concept remain?
>>>>>>> * I think it should remain, as other packaging systems should
>>>>>>> be able to use it as well and end-up is the similar project version.
>>>>>>
>>>>>> I can talk from the Fedora point of view only, as that is what I know a bit.
>>>>>>
>>>>>> In Fedora there can be only one version of a given jar file installed in
>>>>>> the system, so there is no point in adding a version number to the name
>>>>>> of that jar file: the version number is already in the package
>>>>>> containing that jar file. In fact if the build generates jar files with
>>>>>> version numbers in the name the RPM should remove those jar files. That
>>>>>> is why I say that having any kind of numbers in the names of the jars is
>>>>>> not important: we have to remove them anyway.
>>>>>>
>>>>>> Packaging guidelines (see [1]) recommend to avoid version numbers in the
>>>>>> jar files, and I think that makes sense.
>>>>>>
>>>>> This would be the easy solution.
>>>>
>>>> Again talking only about Fedora:
>>>>
>>>> Having just one version of every jar is not simple at all, in fact it
>>>> requires a lot of work to make sure that the selected versions work
>>>> properly together.
>>>>
>>> See below, we actually share the same view...
>>>
>>>>> What happens when you have more than a single Java app, and both
>>>>> using different versions of the same jar file? This means that one
>>>>> of the app's will need to bring it along and use it locally, rather
>>>>> than system-level usage.
>>>>
>>>> What happens is that both applications have to be patched so that they
>>>> work correctly with the same version of that jar file. If possible the
>>>> patches are pushed upstream, if not they applied as part of the package.
>>>> Embedding another version of that jar file in one of the applications is
>>>> not allowed, in fact that is something that packagers have to undo quite
>>>> often.
>>>>
>>> See below... converging into the latest jar is what I figured that
>>> will happen. Still, as I see it such constraints are not really needed.
>>>>> I'm guessing if we assume such a constraint the solution will be
>>>>> to force all app's to use latest jar version, which isn't trivial.
>>>>
>>>> I agree completely, it is not trivial at all, that is where packagers
>>>> expend most of their time.
>>>>
>>>>> So some distro's will allow of concept of slotted installation.
>>>>> This means I currently /have/ 2 working versions of postgres in
>>>>> my laptop (using Gentoo)-
>>>>>
>>>>> equery l postgresql-server
>>>>>  * Searching for postgresql-server ...
>>>>> [IP-] [  ] dev-db/postgresql-server-8.4.11:8.4
>>>>> [IP-] [  ] dev-db/postgresql-server-9.1.3:9.1
>>>>>
>>>>> The same works on my laptop for Maven, Java, Python and many others.
>>>>> If you think about it, Fedora supports slotted installation for
>>>>> kernels, and then added alternatives to do that with other packages
>>>>> as well (mta, Java..). So there's a need and a way to handle several
>>>>> versions of the same library (regardless of the language), and
>>>>> we should be careful when taking such assumptions. At least try
>>>>> to be as flexible as possible, to allow others to join in.
>>>>
>>>> In Fedora that is allowed only for major versions: java-1.7.0 and
>>>> java-1.6.0, maven 2 and maven 3, so on, but not usually for minor
>>>> versions (there are exceptions).
>>>>
>>> It's a good start.
>>>
>>>>> So learning from Fedora I'd say- let the RPM install in a versioned
>>>>> folder (ie- /usr/lib/jvm/jre-1.5.0-gcj/..), and leave the jar
>>>>> files without versions for now. In the future we may need to change it
>>>>> as some disrto's may use sym links to indicate the latest jar.
>>>>> In such a case the RPM will stripdown the version from the artifact.
>>>>
>>>> What we are currently doing with the Fedora ovirt-engine package is that
>>>> jar files are installed to /usr/share/java/ovirt-engine, with names like
>>>> bll.jar, common.jar, compat.jar, etc. The RPM takes care of stripping
>>>> the version numbers generated by the upstream build. This doesn't
>>>> preclude other distros from doing it in a different way, using version
>>>> numbers or symlinks.
>>>>
>>> Why not /usr/share/java/ovirt-engine-3/ ? I do not see someone using
>>> engine3 and engine4 on the same machine, but he may need to have
>>> engine-config v3 to handle previous instance and engine-config v4
>>> to handle current instance, so we could have a good infra if we
>>> keep the major version.
>>
>> The only thing I have against ovirt-engine-3 is that the packaging
>> guidelines recommend to use /usr/share/java/%{name}, where %{name} is
>> the name of the package, and the package has already been approved with
>> the name ovirt-engine. Next major version (not 3.1, that is a minor
>> version) can perfectly be named ovirt-engine4 or ovirt4-engine.
> 
> Maybe open a bz for it so we'll remember?
> Make sure to add this thread so we'll know what happened....

There you go: https://bugzilla.redhat.com/814295