Introduce automatic module names into all libraries being built.

[JonathanGiles]

This is a proposal to fix #691, by adding automatic module names into the built manifest.mf files that ship within the jar files for each library. These names are all proposals and I am happy to change them as you suggest. Thanks.

Fixes #691

[codecov-io]

Codecov Report

Merging #781 into master will decrease coverage by 0.03%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master     #781      +/-   ##
============================================
- Coverage     78.58%   78.55%   -0.04%     
+ Complexity      778      777       -1     
============================================
  Files           101      101              
  Lines          2779     2779              
  Branches        268      268              
============================================
- Hits           2184     2183       -1     
- Misses          493      494       +1     
  Partials        102      102

Impacted Files	Coverage Δ	Complexity Δ
...elemetry/opentracingshim/SpanContextShimTable.java	89.28% <0%> (-7.15%)	7% <0%> (-1%)
...elemetry/sdk/trace/export/BatchSpansProcessor.java	89.65% <0%> (+0.86%)	7% <0%> (ø)	⬇️

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[jkwatson]

Is there any gradle magic we can do so we don't have repeat that jar section in every build.gradle? Some top level allSubModules thing, maybe?

[JonathanGiles]

I wondered the same thing. My Gradle these days is weak, so I was hoping someone else had guidance, otherwise I'll go and research.

[carlosalberto]

It should be possible to re-use this part, although I don't remember myself now the specifics. Once you do this, we should be able to merge this PR.

[jkwatson]

Also, please sign the CLA. :) Thanks very much for the contribution!

[JonathanGiles]

I did sign the CLA today, not sure how long it takes to update...

[jkwatson]

You might need to add a comment saying "I signed it"

[JonathanGiles]

I signed it

[jkwatson]

Guess not. Sometimes that kicks the CLAbot into action

[conniey]

Missing empty newline at the end of these.

[bogdandrutu]

Please fix this everywhere.

[JonathanGiles]

I've added an empty new line to the root build.gradle, as it did not have one (prior to my involvement). All other files no longer have been touched at the end of the file, so they remain as they were.

[thisthat]

Thank you for your contribution :)
I think we can group all these changes in the main build script. We could modify the jar.manifest section to:

jar.manifest {
        ext.moduleName = "io." + project.name.replaceAll("-",".")
        attributes('Implementation-Title': name,
                'Implementation-Version': version,
                'Automatic-Module-Name': moduleName,
                'Built-By': System.getProperty('user.name'),
                'Built-JDK': System.getProperty('java.version'),
                'Source-Compatibility': sourceCompatibility,
                'Target-Compatibility': targetCompatibility)
}

But I am not sure if "io." + project.name.replaceAll("-",".") does all the magic correctly

[JonathanGiles]

I think we should centralise it but still explicitly set the module names. From my experience doing it as you suggest tends to lead to... Surprises after it is too late. But happy to follow consensus...

[thisthat]

With a quick test, I see that there is some difference between package structure and module name. Therefore, I agree with you that setting explicitly the module names is a better strategy on the long term.

[JonathanGiles]

I managed to centralise the configuration into the root build.gradle. Please take another look and let me know of any further concerns. Thanks.

[carlosalberto]

LGTM.

[bogdandrutu]

we don't have "api" in the package names, does that matter?

[JonathanGiles]

No, it doesn't matter. Module names do not need to relate to the package name, although they are a good starting point for choosing a good module name.