pyzfs: python3 support (build system)

Almost all of the Python code in the respository has been updated
to be compatibile with Python 2.6, Python 3.4, or newer.  The only
exceptions are arc_summery3.py which requires Python 3, and pyzfs
which requires at least Python 2.7.  This allows us to maintain a
single version of the code and support most default versions of
python.  This change does the following:

* Sets the default shebang for all Python scripts to python3.  If
  only Python 2 is available, then at install time scripts which
  are compatible with Python 2 will have their shebangs replaced
  with /usr/bin/python.  This is done for compatibility until
  Python 2 goes end of life.  Since only the installed versions
  are changed this means Python 3 must be installed on the system
  for test-runner when testing in-tree.

* Added --with-python=<2|3|3.4,etc> configure option which sets
  the PYTHON environment variable to target a specific python
  version.  By default the newest installed version of Python
  will be used or the preferred distribution version when
  creating pacakges.

* Fixed --enable-pyzfs configure checks so they are run when
  --enable-pyzfs=check and --enable-pyzfs=yes.

* Enabled pyzfs for Python 3.4 and newer, which is now supported.

* Renamed pyzfs package to python<VERSION>-pyzfs and updated to
  install in the appropriate site location.  For example, when
  building with --with-python=3.4 a python34-pyzfs will be
  created which installs in /usr/lib/python3.4/site-packages/.

* Renamed the following python scripts according to the Fedora
  guidance for packaging utilities in /bin

  - dbufstat.py     -> dbufstat
  - arcstat.py      -> arcstat
  - arc_summary.py  -> arc_summary
  - arc_summary3.py -> arc_summary3

* Updated python-cffi package name.  On CentOS 6, CentOS 7, and
  Amazon Linux it's called python-cffi, not python2-cffi.  For
  Python3 it's called python3-cffi or python3x-cffi.

* Install one version of arc_summary.  Depending on the version
  of Python available install either arc_summary2 or arc_summary3
  as arc_summary.  The user output is only slightly different.

Reviewed-by: John Ramsden <[email protected]>
Reviewed-by: Neal Gompa <[email protected]>
Reviewed-by: loli10K <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #8096

1 files changed, 56 insertions, 23 deletions

diff --git a/rpm/generic/zfs.spec.in b/rpm/generic/zfs.spec.in
index 55edbc83f..533792989 100644
--- a/rpm/generic/zfs.spec.in
+++ b/rpm/generic/zfs.spec.in
@@ -53,16 +53,6 @@
 %bcond_with    asan
 %bcond_with    systemd
 
-# Python permits the !/usr/bin/python shebang for scripts that are cross
-# compatible between python2 and python3, but Fedora 28 does not.  Fedora
-# wants us to choose python3 for cross-compatible scripts.  Since we want
-# to support python2 and python3 users, exclude our scripts from Fedora 28's
-# RPM build check, so that we don't get a bunch of build warnings.
-#
-# Details: https://github.com/zfsonlinux/zfs/issues/7360
-#
-%global __brp_mangle_shebangs_exclude_from arc_summary.py|arcstat.py|dbufstat.py|test-runner.py|zts-report.py
-
 # Generic enable switch for systemd
 %if %{with systemd}
 %define _systemd 1
@@ -85,6 +75,32 @@
 %define _systemd 1
 %endif
 
+# When not specified default to distribution provided version.  This
+# is normally Python 3, but for RHEL <= 7 only Python 2 is provided.
+%if %{undefined __use_python}
+%if 0%{?rhel} && 0%{?rhel} <= 7
+%define __python              /usr/bin/python2
+%define __python_pkg_version  2
+%define __python_cffi_pkg     python-cffi
+%else
+%define __python              /usr/bin/python3
+%define __python_pkg_version  3
+%define __python_cffi_pkg     python3-cffi
+%endif
+%else
+%define __python              %{__use_python}
+%define __python_pkg_version  %{__use_python_pkg_version}
+%define __python_cffi_pkg     python%{__python_pkg_version}-cffi
+%endif
+
+# By default python-pyzfs is enabled, with the exception of
+# RHEL 6 which by default uses Python 2.6 which is too old.
+%if 0%{?rhel} == 6
+%bcond_with    pyzfs
+%else
+%bcond_without pyzfs
+%endif
+
 Name:           @PACKAGE@
 Version:        @VERSION@
 Release:        @RELEASE@%{?dist}
@@ -135,7 +151,7 @@ Requires:  util-linux
 Requires:  sysstat
 
 %description
-This package contains the ZFS command line utilities.
+This package contains the core ZFS command line utilities.
 
 %package -n libzpool2
 Summary:        Native ZFS pool library for Linux
@@ -219,6 +235,7 @@ Requires:       acl
 Requires:       sudo
 Requires:       sysstat
 Requires:       libaio
+Requires:       python%{__python_pkg_version}
 %if 0%{?rhel}%{?fedora}%{?suse_version}
 BuildRequires:  libaio-devel
 %endif
@@ -240,23 +257,23 @@ Requires:       grep
 This package contains a dracut module used to construct an initramfs
 image which is ZFS aware.
 
-%if 0%{?_pyzfs}
-%package -n pyzfs
-Summary:        Python wrapper for libzfs_core
+%if %{with pyzfs}
+%package -n python%{__python_pkg_version}-pyzfs
+Summary:        Python %{python_version} wrapper for libzfs_core
 Group:          Development/Languages/Python
 License:        Apache-2.0
 BuildArch:      noarch
 Requires:       libzfs2 = %{version}
 Requires:       libnvpair1 = %{version}
 Requires:       libffi
-Requires:       python >= 2.7
-Requires:       python-cffi
+Requires:       python%{__python_pkg_version}
+Requires:       %{__python_cffi_pkg}
 %if 0%{?rhel}%{?fedora}%{?suse_version}
-BuildRequires:  python-devel
+BuildRequires:  python%{__python_pkg_version}-devel
 BuildRequires:  libffi-devel
 %endif
 
-%description -n pyzfs
+%description -n python%{__python_pkg_version}-pyzfs
 This package provides a python wrapper for the libzfs_core C library.
 %endif
 
@@ -299,6 +316,12 @@ image which is ZFS aware.
     %define systemd --enable-sysvinit --disable-systemd
 %endif
 
+%if %{with pyzfs}
+    %define pyzfs --enable-pyzfs
+%else
+    %define pyzfs --disable-pyzfs
+%endif
+
 %setup -q
 
 %build
@@ -307,11 +330,13 @@ image which is ZFS aware.
     --with-udevdir=%{_udevdir} \
     --with-udevruledir=%{_udevruledir} \
     --with-dracutdir=%{_dracutdir} \
+    --with-python=%{__python} \
     --disable-static \
     %{debug} \
     %{debuginfo} \
     %{asan} \
-    %{systemd}
+    %{systemd}\
+    %{pyzfs}
 make %{?_smp_mflags}
 
 %install
@@ -379,12 +404,20 @@ systemctl --system daemon-reload >/dev/null || true
 %endif
 
 %files
+# Core utilities
 %{_sbindir}/*
-%{_bindir}/*
-%{_libexecdir}/%{name}
+%{_bindir}/raidz_test
+%{_bindir}/zgenhostid
+# Optional Python 2/3 scripts
+%{_bindir}/arc_summary
+%{_bindir}/arcstat
+%{_bindir}/dbufstat
+# Man pages
 %{_mandir}/man1/*
 %{_mandir}/man5/*
 %{_mandir}/man8/*
+# Configuration files and scripts
+%{_libexecdir}/%{name}
 %{_udevdir}/vdev_id
 %{_udevdir}/zvol_id
 %{_udevdir}/rules.d/*
@@ -426,8 +459,8 @@ systemctl --system daemon-reload >/dev/null || true
 %doc contrib/dracut/README.dracut.markdown
 %{_dracutdir}/modules.d/*
 
-%if 0%{?_pyzfs}
-%files -n pyzfs
+%if %{with pyzfs}
+%files -n python%{__python_pkg_version}-pyzfs
 %doc contrib/pyzfs/README
 %doc contrib/pyzfs/LICENSE
 %defattr(-,root,root,-)