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2 Commits

Author SHA1 Message Date
Ryan Moeller 088f97b921 Canonicalize Python shebangs
/usr/bin/env python3 is the suggested[1] shebang for Python in general
(likewise for python2) and is conventional across platforms. This eases
development on systems where python is not installed in /usr/bin
(FreeBSD for example) and makes it possible to develop in virtual
environments (venv) for isolating dependencies.

Many packaging guidelines discourage the use of /usr/bin/env, but since
this is the canonical way of writing shebangs in the Python community,
many packaging scripts are already equipped to handle substituting the
appropriate absolute path to python automatically.

Some RPM package builders lacking brp-mangle-shebangs need a small
fallback mechanism in the package spec to stamp the appropriate shebang
on installed Python scripts.

[1]: https://docs.python.org/3/using/unix.html?#miscellaneous

Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Ryan Moeller <ryan@ixsystems.com>
Closes #9314
2020-01-22 13:49:00 -08:00
Brian Behlendorf 6e72a5b9b6 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 <johnramsden@riseup.net>
Reviewed-by: Neal Gompa <ngompa@datto.com>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #8096
2019-01-06 10:39:41 -08:00