Adding Python support for Ganglia - gmond on Centos / RHEL
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While creating Ganglia RPM packages for my Centos repository I got stuck with a lack of Python support in Ganglia - gmond. I'll try to to explain details of this whole issue.
First of all one could just install ganglia-gmond packages from Epel repo - and that will make the general case. I checked EPEL packages and those contain modpython.so so go for it ;) But I just couldn't go that way as I had to create my own packages.
First of all - let's check the compilation params regarding to Python:
[root@vm-2-repo ganglia-gmond-3.6.0]# ./configure --help | grep -i python
--disable-python exclude mod_python and support for metric modules written in python
--with-python=PATH Specify prefix for python or full path to interpreter
So by default there should be Python support builtin. But after compiling & building there's no modpython.so library on /usr/lib64/ganglia and that is weird. Digging deeper in config.log there's:
configure:11482: checking for python
configure:11500: found /usr/bin/python
configure:11512: result: /usr/bin/python
configure:11528: checking Python version
configure:11532: result: 2.6
configure:11554: checking Python support
configure:11556: result: no
Hmm - that's really weird. Let's go even more deeper - now with configure.ac:
AC_ARG_WITH( python,
[ --with-python=PATH Specify prefix for python or full path to interpreter],
[if test x"$withval" != xno; then enable_python="yes"; PYTHON_BIN="$withval"; fi])
[...]
AC_ARG_ENABLE( python,
[ --disable-python exclude mod_python and support for metric modules written
in python],
[ if test x"$enableval" != xyes; then enable_python="no"; fi ], [ enable_python="yes" ] )
Ok so it's true - by default there should be Python support. Let's check further (still configure.ac):
if test x"$enable_python" = xyes; then
echo
echo Checking for python
# check for Python executable
if test -z "$PYTHON_BIN"; then
AC_PATH_PROG(PYTHON_BIN, python)
else
if test -d "$PYTHON_BIN"; then
PYTHON_BIN="$PYTHON_BIN/bin/python"
fi
fi
if test -n "$PYTHON_BIN"; then
# find out python version
AC_MSG_CHECKING(Python version)
PyVERSION=`$PYTHON_BIN -c ['import sys; print sys.version[:3]'`]
PyMAJVERSION=`$PYTHON_BIN -c ['import sys; print sys.version[:1]'`]
AC_MSG_RESULT($PyVERSION)
PYTHON_VERSION=$PyVERSION
AC_SUBST(PYTHON_VERSION)
PyEXEC_INSTALLDIR=`$PYTHON_BIN -c "import sys; print sys.exec_prefix"`
if test -f "$PyEXEC_INSTALLDIR/include/python/Python.h"; then
PYTHON_INCLUDES="-I$PyEXEC_INSTALLDIR/include/python"
else
if test -f "$PyEXEC_INSTALLDIR/include/python$PyVERSION/Python.h"; then
PYTHON_INCLUDES="-I$PyEXEC_INSTALLDIR/include/python$PyVERSION"
else
PYTHON_INCLUDES=""
enable_python="no"
fi
fi
AC_SUBST(PYTHON_INCLUDES)
else
enable_python="no"
fi
fi
Ah crap - and here it is. Python support will be disabled and modpython.so library won't be created when there's no header files for Python on our OS. You can make sure if there is Python.h by using locate / find / whatever.
Solution? Just:
yum install python-devel
And that will make it.