Hi All-
TL;DR - I am proposing that we encourage versions in Brooklyn of the form "1.1.0" or "1.2-qualifier" such as
"1.2-SNAPSHOT", silently mapping when needed to OSGi as "1.1.0" or "1.2.0.qualifier" /
"1.2.0.SNAPSHOT"
Further to my last mail -- we have a bit of discord between various versioning
schemes--
* GitHub SemVer - which everyone talks lovingly about (though often not
knowledgeably, and it's stricter than I realized!)
* OSGi versioning - a precursor to (1), in widespread use but I've never heard
anyone say anything nice about it
* Maven - allows whatever you want but has recommendations and conventions most
people kinda follow
They all agree on up to three numbers at the start. It's what comes after that varies, usually either a
"-" (semver, maven, conventions) or "." (osgi), followed by qualifiers. If practice
almost everyone seems to do "-" followed by qualifiers -- however qualifiers in practice often
don't follow the strict constraints of semver (no leading zeroes, no underscores) nor some of the maven
recommendations (use of build number).
(Detailed summary on SemVer and OSGi versioning is included below for
reference.)
So far, Brooklyn hasn't had an opinion and I liked it that way. However when
registering OSGi bundles we MUST confirm with OSGi versioning there. I'm
pretty sure it's NOT desirable to enforce OSGi versioning on types, given that
few people use it. BUT we are moving to a world where I think we want type
versions (entity versions etc) to align with bundle versions: there is really
no point in types having different versions to their defining bundle! This
makes for an incompatibility between what people would naturally use and what
we have to use within OSGi.
With examples, my assumption is that people want to use and see strings like
"1.1-SNAPSHOT". But under the covers the OSGi bundle needs to have
"1.1.0.SNAPSHOT".
I propose we resolve this by recommending a version syntax which fits what most
things people are doing and which is bi-di mappable to OSGi. We use this
version everywhere except where a strict OSGi version is needed. We WARN if we
get a non-compliant version in a place which might be ambiguous. And we
minimise places where we need to rely on mapping. (The main place a mapping is
needed is if we need to create an OSGi version or compare with an OSGi version.)
Specifically I propose that Brooklyn type versions SHOULD be:
<major> ( "." <minor> ( "." <patch> ")? )? ( "-" <qualifier>) ?
where qualifier can have letters, numbers, "-" or "_" but NOT additional
".".
We construct an OSGi version, when needed, by replacing the first "-" with "." and inserting 0's if
needed for a missing minor/patch. So "1.1-SNAPSHOT" becomes "1.1.0.SNAPSHOT" when an OSGi version
is needed.
Note that the above is a SHOULD. The only strict requirement is the version string MUST
NOT contain a ":". (That breaks parsing.)
Where non-compliant versions are supplied, we WARN, but things work. We apply simple heuristics to create a valid OSGi version -- but the
problem is that we can no longer guarantee uniqueness ("0.0.0-a" and "0.0.0.a" would be conflated), and the result is
possibly quite different to the input (eg "v1" would become "0.0.0.v1"). For this reason if given a non-compliant
version string we WARN what the result is and that the resulting OSGi version could conflict with similar but not-identical version strings
-- but things work fine unless someone is trying to have different bundles for "0.0.0-a" and "0.0.0.a"!
(If version is taken from MANIFEST.MF we reverse map to find the brooklyn type versions, by changing the
".<qualifier>" to "-<qualifier>"; no warning is needed here however as there is
no risk of non-uniqueness.)
Returning to examples:
* If a user specifies "1.1-SNAPSHOT" that's what they will see everywhere except deep
within OSGi where they will see "1.1.0.SNAPSHOT"
* If a user includes a MANIFEST.MF they would have to use "1.1.0.SNAPSHOT" syntax there; they should still use "1.1-SNAPSHOT" in
the catalog.bom (or "1.1.0-SNAPSHOT" would be fine too). If they use "1.1.0.SNAPSHOT" in the catalog.bom things will work, but
they will get a warning, and "1.1.0-SNAPSHOT" is what will display in the UI. If a different number or qualifier (eg
"1.2.0-SNAPSHOT" or "1.1-beta") is used, it will give an ERROR because the mapping will make an inconsistent OSGi version.
I think the only other big options are to require OSGi everywhere (user unfriendly, and
bad for backwards compatibility) or completely decouple OSGi bundle version from type
versions (overly confusing). So while I'm reluctant to get in to the "versions
should look like XXX" I think it's worth it to play nicely in OSGi and semver, and
the above I think is the simplest and best way (even if the technicalities don't look so
simple on first read!).
That said if there are version strings people want that aren't going to be
well-supported with this proposal, please shout now!
Best
Alex
APPENDIX - Comparison of SemVer and OSGi
GITHUB SEMVER - https://github.com/mojombo/semver/blob/master/semver.md
*<major> "." <minor> "." <patch> ( "-" <pre_release_id> )? ( "+" <build_id> )?*
The first three parts are numbers.
Where <pre_release_id> and <build_id> are dot-separated tokens made up of letters,
digits, and "-".
Key things:
* numbers and and pre_release_id tokens must not consist of numbers with leading zeros (e.g. "1.01"
is not valid, nor is "1.0.0-01"; but "1.0.0+01" is)
* "-" immediately after the patch indicates pre-release and special precedence
rules apply
* build-id metadata should be ignored when computing precedence
OSGI VERSIONING - https://www.osgi.org/release-4-version-4-3-download/ -
sections 1.3.2 and 3.2.5
*<major> ( "." <minor> ( "." <micro> ( "." <qualifier> )? )? )?*
The first three parts are the same as semver, except leading zeros are allowed.
<qualifier> consists of letters, numbers, "-", and "_".
SUMMARY OF DIFFERENCES
(1) OSGi allows abbreviating when there is no qualifier data (e.g. "1.1") whereas semver
doesn't (has to be "1.1.0")
(2) OSGi requires a dot before the qualifier, whereas semver uses "-" or "+"
depending on what the qualifier is meant for
(3) OSGi permits underscores but not dots; semver permits dots to separate
non-empty tokens
END
