cmake: fix build WITH_SYSTEM_BOOST=ON

[tchaikov]

FindBoost.cmake from upstream cmake now finds python libraries like

find_package(Boost 1.67 python36)

and it export targets like Boost::python36

but we are still linking against Boost::python, so to be compatible
with FindBoost.cmake, we need to update BuildBoost.cmake and
mgr/CMakeLists.txt accordingly. in other words, to export
Boost::python36 and to link Boost::python36.

Signed-off-by: Kefu Chai kchai@redhat.com

• References tracker ticket
• Updates documentation if necessary
• Includes tests for new functionality or reproducer for bug

[wjwithagen]

@tchaikov
Not sure if this is going to fly with the CMake stuff that is in FreeBSD packages.
I always have this struggle on a Boost upgrade with FreeBSD that CMake is lagging.
And there might be some different opinions on how to handle python 27 versus 36.
So I'll throw this into Jenkins and see what comes of it.

[tchaikov]

https://shaman.ceph.com/builds/ceph/wip-kefu-testing-2018-08-10-1333/a840fb77db52e72436a09180408aeef9a4375984/

[wjwithagen]

Have had several Jenkins runs already with this patch.
Latest:
http://cephdev.digiware.nl:8180/jenkins/job/ceph-master/2426/console

[tchaikov]

@wjwithagen thanks for testing!

[wjwithagen]

@tchaikov
As far as I can tell I need a small bit of this PR backported to mimic:
mimic : src/CMakeLists.txt:770
refers to Boost::python, which fails while building on FreeBSD.
Any chance to cherrypick anything, or should I just commit a PR against mimic?

[tchaikov]

no, i don't think so. as it does not break the build. i introduced this fix just to enable Ceph to find pre-built ceph-libboost-* packages when running make check . please follow the instructions at #26277 (comment) for backporting the changes.

[wjwithagen]

@tchaikov
I'm not quite getting what you mean?
I would need to have:
mimic : src/CMakeLists.txt:770 look like:

target_link_libraries(ceph-mgr
  osdc client heap_profiler
  osdc client heap_profiler
  global-static ceph-common
  global-static ceph-common
  Boost::python ${MGR_PYTHON_LIBRARIES} ${CMAKE_DL_LIBS})
  Boost::python${MGR_PYTHON_VERSION_MAJOR}${MGR_PYTHON_VERSION_MINOR}
  ${MGR_PYTHON_LIBRARIES} ${CMAKE_DL_LIBS})

But I think that cannot be cherrypicked, so it warants a separate PR.
I can still follow @smithfarm's suggestions on how to backport.

[tchaikov]

i was trying to answer your question.

Any chance to cherrypick anything,

no, i don't think so. as it does not break the build. i introduced this fix just to enable Ceph to find pre-built ceph-libboost-* packages when running make check .

or should I just commit a PR against mimic?

please follow the instructions at #26277 (comment) for backporting the changes.

[wjwithagen]

Tracker: http://tracker.ceph.com/issues/38213

[wjwithagen]

@smithfarm
backport PR #26300