build on MacOS

Since we've switched to C++ 17, and the default clang shipped with Xcode 9 does not support all the C++ 17 language features, it's suggested to install clang using brew::

brew install llvm

and install all the necessary bits::

brew install snappy ccache cmake pkg-config bash gnu-getopt pip install cython

install FUSE if you want to build the FUSE support::

brew cask install osxfuse

then, under the source directory of Ceph::

mkdir build cd build export PKG_CONFIG_PATH=/usr/local/Cellar/nss/3.48/lib/pkgconfig:/usr/local/Cellar/openssl/1.0.2t/lib/pkgconfig cmake .. -DBOOST_J=4
-DCMAKE_C_COMPILER=/usr/local/opt/llvm/bin/clang
-DCMAKE_CXX_COMPILER=/usr/local/opt/llvm/bin/clang++
-DCMAKE_EXE_LINKER_FLAGS="-L/usr/local/opt/llvm/lib"
-DENABLE_GIT_VERSION=OFF
-DSNAPPY_ROOT_DIR=/usr/local/Cellar/snappy/1.1.7_1
-DWITH_BABELTRACE=OFF
-DWITH_BLUESTORE=OFF
-DWITH_CCACHE=OFF
-DWITH_CEPHFS=OFF
-DWITH_KRBD=OFF
-DWITH_LIBCEPHFS=OFF
-DWITH_LTTNG=OFF
-DWITH_LZ4=OFF
-DWITH_MANPAGE=ON
-DWITH_MGR=OFF
-DWITH_MGR_DASHBOARD_FRONTEND=OFF
-DWITH_RADOSGW=OFF
-DWITH_RDMA=OFF
-DWITH_SPDK=OFF
-DWITH_SYSTEMD=OFF
-DWITH_TESTS=OFF
-DWITH_XFS=OFF

The paths to nss and snappy might vary if newer versions of the packages are installed.

Also, please consider using boost v1.69 to address the bug of https://github.com/boostorg/atomic/issues/15.

Currently, the most practical uses for Ceph on MacOS might be FUSE and some other librados based applications.