gfapi.py: support dynamic loading of versioned libraries

Currently gfapi.py only loads libraries by filename ending in ".so".  On
an installed system without development packages, the <lib>.so filenames
are not available. ctypes.util.find_library() can be used to detect the
files dynamically.

In addition to this, also fixing some minor indention errors and package
the library into the Python site-packages path. Python applications and
libraries can now access libgfapi through 'from glusterfs import gfapi'.

Change-Id: I71e38dabd3ade5dcf24813bf2fc25cda91b571c6
BUG: 1005146
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-on: http://review.gluster.org/5835
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>

Author: nixpanic

.gitignore

@@ -22,25 +22,27 @@ Makefile
 stamp-h1
 
 # Generated files
-ufo/.tox
-ufo/test/unit/.coverage
+api/examples/__init__.py*
+api/examples/setup.py
+argp-standalone/libargp.a
 contrib/uuid/uuid_types.h
-extras/who-wrote-glusterfs/gitdm
-extras/init.d/glusterd.plist
 extras/init.d/glusterd-Debian
 extras/init.d/glusterd-Redhat
 extras/init.d/glusterd-SuSE
+extras/init.d/glusterd.plist
 extras/ocf/glusterd
 extras/ocf/volume
-glusterfs.spec
+extras/who-wrote-glusterfs/gitdm
 glusterfs-api.pc
-libtool
-xlators/mount/fuse/utils/mount.glusterfs
-xlators/mount/fuse/utils/mount_glusterfs
-argp-standalone/libargp.a
+glusterfs.spec
 glusterfsd/src/glusterfsd
+libgfchangelog.pc
 libglusterfs/src/spec.lex.c
 libglusterfs/src/y.tab.c
 libglusterfs/src/y.tab.h
-libgfchangelog.pc
+libtool
 run-tests.sh
+ufo/.tox
+ufo/test/unit/.coverage
+xlators/mount/fuse/utils/mount.glusterfs
+xlators/mount/fuse/utils/mount_glusterfs

api/Makefile.am

@@ -1 +1 @@
-SUBDIRS = src
+SUBDIRS = src examples

api/examples/Makefile.am

@@ -1,4 +1,6 @@
-noinst_PROGRAMS = glfsxmp
+EXTRA_PROGRAMS = glfsxmp
 glfsxmp_SOURCES = glfsxmp.c
 glfsxmp_CFLAGS = $(GLFS_CFLAGS) -Wall
-glfsxmp_LDADD = $(GLFS_LIBS)
+glfsxmp_LDADD = $(GLFS_LIBS)
+
+EXTRA_DIST = gfapi.py

api/examples/gfapi.py

@@ -1,16 +1,17 @@
 #!/usr/bin/python
 
 from ctypes import *
+from ctypes.util import find_library
 import os
 import sys
 import time
 import types
 
 # Looks like ctypes is having trouble with dependencies, so just force them to
 # load with RTLD_GLOBAL until I figure that out.
-glfs = CDLL("libglusterfs.so",RTLD_GLOBAL)
-xdr = CDLL("libgfxdr.so",RTLD_GLOBAL)
-api = CDLL("libgfapi.so",RTLD_GLOBAL)
+glfs = CDLL(find_library("glusterfs"),RTLD_GLOBAL)
+xdr = CDLL(find_library("gfxdr"),RTLD_GLOBAL)
+api = CDLL(find_library("gfapi"),RTLD_GLOBAL)
 
 # Wow, the Linux kernel folks really play nasty games with this structure.  If
 # you look at the man page for stat(2) and then at this definition you'll note
@@ -98,10 +99,12 @@ def read_buffer (self, buf, flags=0):
         def write (self, data, flags=0):
                 return api.glfs_write(self.fd,data,len(data),flags)
 
-	def fallocate (self, mode, offset, len):
-		return api.glfs_fallocate(self.fd, mode, offset, len)
-	def discard (self, offset, len):
-		return api.glfs_discard(self.fd, offset, len)
+        def fallocate (self, mode, offset, len):
+            return api.glfs_fallocate(self.fd, mode, offset, len)
+
+        def discard (self, offset, len):
+            return api.glfs_discard(self.fd, offset, len)
+
 
 class Dir(object):
 
@@ -381,7 +384,7 @@ def test_fallocate (vol, path, data):
                 test_setxattr,
                 test_getxattr,
                 test_listxattr,
-		test_fallocate,
+                test_fallocate,
         )
 
         ok_to_fail = (

api/examples/setup.py.in

@@ -0,0 +1,29 @@
+from distutils.core import setup
+
+# generate a __init__.py for the package namespace
+fo = open('__init__.py', 'w')
+fo.write('__version__ = "@PACKAGE_VERSION@"\n')
+fo.close()
+
+DESC = """GlusterFS is a clustered file-system capable of scaling to
+several petabytes. It aggregates various storage bricks over Infiniband
+RDMA or TCP/IP interconnect into one large parallel network file system.
+GlusterFS is one of the most sophisticated file systems in terms of
+features and extensibility.  It borrows a powerful concept called
+Translators from GNU Hurd kernel. Much of the code in GlusterFS is in
+user space and easily manageable.
+
+This package contains the Python interface to the libgfapi library."""
+
+setup(
+    name='glusterfs-api',
+    version='@PACKAGE_VERSION@',
+    description='Python client library for the GlusterFS libgfapi',
+    long_description=DESC,
+    author='Gluster Community',
+    author_email='gluster-devel@nongnu.org',
+    license='LGPLv3',
+    url='http://gluster.org/',
+    package_dir={'gluster':''},
+    packages=['gluster']
+)

configure.ac

@@ -164,6 +164,8 @@ AC_CONFIG_FILES([Makefile
                 libgfchangelog.pc
                 api/Makefile
                 api/src/Makefile
+                api/examples/Makefile
+                api/examples/setup.py
 		geo-replication/Makefile
 		geo-replication/src/Makefile
 		geo-replication/syncdaemon/Makefile

glusterfs.spec.in

@@ -63,6 +63,12 @@
 %global           _with_systemd true
 %endif
 
+# From https://fedoraproject.org/wiki/Packaging:Python#Macros
+%if ( 0%{?rhel} && 0%{?rhel} <= 5 )
+%{!?python_sitelib: %global python_sitelib %(%{__python} -c "from distutils.sysconfig import get_python_lib; print(get_python_lib())")}
+%{!?python_sitearch: %global python_sitearch %(%{__python} -c "from distutils.sysconfig import get_python_lib; print(get_python_lib(1))")}
+%endif
+
 Summary:          Cluster File System
 %if ( 0%{_for_fedora_koji_builds} )
 Name:             glusterfs
@@ -315,6 +321,8 @@ This package provides the glusterfs server daemon.
 Summary:          Clustered file-system api library
 Group:            System Environment/Daemons
 Requires:         %{name} = %{version}-%{release}
+# we provide the Python package/namespace 'gluster'
+Provides:         python-gluster = %{version}-%{release}
 
 %description api
 GlusterFS is a clustered file-system capable of scaling to several
@@ -325,7 +333,7 @@ terms of features and extensibility.  It borrows a powerful concept
 called Translators from GNU Hurd kernel. Much of the code in GlusterFS
 is in user space and easily manageable.
 
-This package provides the glusterfs libgfapi library
+This package provides the glusterfs libgfapi library.
 
 %if ( 0%{!?_without_ocf:1} )
 %package resource-agents
@@ -437,9 +445,17 @@ regression testing of Gluster.
 
 %{__make} %{?_smp_mflags}
 
+pushd api/examples
+FLAGS="$RPM_OPT_FLAGS" %{__python} setup.py build
+popd
+
 %install
 %{__rm} -rf %{buildroot}
 %{__make} install DESTDIR=%{buildroot}
+# install the gfapi Python library in /usr/lib/python*/site-packages
+pushd api/examples
+%{__python} setup.py install --skip-build --verbose --root %{buildroot}
+popd
 # Install include directory
 %{__mkdir_p} %{buildroot}%{_includedir}/glusterfs
 %{__install} -p -m 0644 libglusterfs/src/*.h \
@@ -768,6 +784,7 @@ fi
 %exclude %{_libdir}/*.so
 %{_libdir}/libgfapi.*
 %{_libdir}/glusterfs/%{version}%{?prereltag}/xlator/mount/api*
+%{python_sitelib}/*
 
 %if ( 0%{!?_without_ocf:1} )
 %files resource-agents
@@ -858,6 +875,9 @@ if [ $1 -ge 1 ]; then
 fi
 
 %changelog
+* Thu Sep 30 2013 Niels de Vos <ndevos@redhat.com>
+- Package gfapi.py into the Python site-packages path (#1005146)
+
 * Tue Sep 17 2013 Harshavardhana <fharshav@redhat.com>
 - Provide a new package called "glusterfs-regression-tests" for standalone
   regression testing.