Removed Python 2 and Python 3.5- support

Deprecation of Python versions below 3.6 gives opportunity to unify the
build and install requirements for OpenZFS packages. The minimal
supported Python version is 3.6 as this is the most recent Python
package CentOS/RHEL 7 users can get.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Rich Ercolani <rincebrain@gmail.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Signed-off-by: szubersk <szuberskidamian@gmail.com>
Closes #12925

.github/workflows/checkstyle.yaml

@@ -15,7 +15,7 @@ jobs:
       run: |
         sudo apt-get update
         sudo apt-get install --yes -qq build-essential autoconf libtool gawk alien fakeroot linux-headers-$(uname -r)
-        sudo apt-get install --yes -qq zlib1g-dev uuid-dev libattr1-dev libblkid-dev libselinux-dev libudev-dev libssl-dev python-dev python-setuptools python-cffi python3 python3-dev python3-setuptools python3-cffi
+        sudo apt-get install --yes -qq zlib1g-dev uuid-dev libattr1-dev libblkid-dev libselinux-dev libudev-dev libssl-dev python3 python3-dev python3-setuptools python3-cffi
         # packages for tests
         sudo apt-get install --yes -qq parted lsscsi ksh attr acl nfs-kernel-server fio
         sudo apt-get install --yes -qq mandoc cppcheck pax-utils devscripts

.github/workflows/zfs-tests-functional.yml

@@ -25,9 +25,8 @@ jobs:
           zlib1g-dev uuid-dev libblkid-dev libselinux-dev \
           xfslibs-dev libattr1-dev libacl1-dev libudev-dev libdevmapper-dev \
           libssl-dev libffi-dev libaio-dev libelf-dev libmount-dev \
-          libpam0g-dev pamtester python-dev python-setuptools python-cffi \
+          libpam0g-dev pamtester libcurl4-openssl-dev \
-          python-packaging python3 python3-dev python3-setuptools python3-cffi \
+          python3 python3-dev python3-setuptools python3-cffi python3-packaging
-          libcurl4-openssl-dev python3-packaging
     - name: Autogen.sh
       run: |
         sh autogen.sh

.github/workflows/zfs-tests-sanity.yml

@@ -21,9 +21,8 @@ jobs:
           zlib1g-dev uuid-dev libblkid-dev libselinux-dev \
           xfslibs-dev libattr1-dev libacl1-dev libudev-dev libdevmapper-dev \
           libssl-dev libffi-dev libaio-dev libelf-dev libmount-dev \
-          libpam0g-dev pamtester python-dev python-setuptools python-cffi \
+          libpam0g-dev pamtester libcurl4-openssl-dev \
-          python-packaging python3 python3-dev python3-setuptools python3-cffi \
+          python3 python3-dev python3-setuptools python3-cffi python3-packaging
-          python3-packaging libcurl4-openssl-dev
     - name: Autogen.sh
       run: |
         sh autogen.sh

.github/workflows/zloop.yml

@@ -22,7 +22,6 @@ jobs:
           xfslibs-dev libattr1-dev libacl1-dev libudev-dev libdevmapper-dev \
           libssl-dev libffi-dev libaio-dev libelf-dev libmount-dev \
           libpam0g-dev \
-          python-dev python-setuptools python-cffi python-packaging \
           python3 python3-dev python3-setuptools python3-cffi python3-packaging
     - name: Autogen.sh
       run: |

cmd/arc_summary/Makefile.am

@@ -1,13 +1,8 @@
 bin_SCRIPTS = arc_summary
 
 CLEANFILES = arc_summary
-EXTRA_DIST = arc_summary2 arc_summary3
+EXTRA_DIST = arc_summary3
-
-if USING_PYTHON_2
-SCRIPT = arc_summary2
-else
 SCRIPT = arc_summary3
-endif
 
 arc_summary: $(SCRIPT)
 	cp $< $@

cmd/arc_summary/arc_summary3

@@ -191,21 +191,13 @@ elif sys.platform.startswith('linux'):
         # there, so we fall back on modinfo
         command = ["/sbin/modinfo", request, "-0"]
 
-        # The recommended way to do this is with subprocess.run(). However,
-        # some installed versions of Python are < 3.5, so we offer them
-        # the option of doing it the old way (for now)
         info = ''
 
         try:
 
-            if 'run' in dir(subprocess):
+            info = subprocess.run(command, stdout=subprocess.PIPE,
-                info = subprocess.run(command, stdout=subprocess.PIPE,
+                                  check=True, universal_newlines=True)
-                                      universal_newlines=True)
+            raw_output = info.stdout.split('\0')
-                raw_output = info.stdout.split('\0')
-            else:
-                info = subprocess.check_output(command,
-                                               universal_newlines=True)
-                raw_output = info.split('\0')
 
         except subprocess.CalledProcessError:
             print("Error: Descriptions not available",

cmd/arcstat/arcstat.in

@@ -47,7 +47,7 @@
 # @hdr is the array of fields that needs to be printed, so we
 # just iterate over this array and print the values using our pretty printer.
 #
-# This script must remain compatible with Python 2.6+ and Python 3.4+.
+# This script must remain compatible with Python 3.6+.
 #
 
 import sys

cmd/dbufstat/dbufstat.in

@@ -27,7 +27,7 @@
 # Copyright (C) 2013 Lawrence Livermore National Security, LLC.
 # Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
 #
-# This script must remain compatible with Python 2.6+ and Python 3.4+.
+# This script must remain compatible with and Python 3.6+.
 #
 
 import sys

config/always-python.m4

@@ -1,7 +1,6 @@
 dnl #
 dnl # The majority of the python scripts are written to be compatible
-dnl # with Python 2.6 and Python 3.4.  Therefore, they may be installed
+dnl # with Python 3.6. This option is intended to
-dnl # and used with either interpreter.  This option is intended to
 dnl # to provide a method to specify the default system version, and
 dnl # set the PYTHON environment variable accordingly.
 dnl #
@@ -13,9 +12,7 @@ AC_DEFUN([ZFS_AC_CONFIG_ALWAYS_PYTHON], [
 		[with_python=check])
 
 	AS_CASE([$with_python],
-		[check], [AC_CHECK_PROGS([PYTHON], [python3 python2], [:])],
+		[check], [AC_CHECK_PROGS([PYTHON], [python3], [:])],
-		[2*], [PYTHON="python${with_python}"],
-		[*python2*], [PYTHON="${with_python}"],
 		[3*], [PYTHON="python${with_python}"],
 		[*python3*], [PYTHON="${with_python}"],
 		[no], [PYTHON=":"],
@@ -23,8 +20,7 @@ AC_DEFUN([ZFS_AC_CONFIG_ALWAYS_PYTHON], [
 	)
 
 	dnl #
-	dnl # Minimum supported Python versions for utilities:
+	dnl # Minimum supported Python versions for utilities: Python 3.6
-	dnl # Python 2.6 or Python 3.4
 	dnl #
 	AM_PATH_PYTHON([], [], [:])
 	AS_IF([test -z "$PYTHON_VERSION"], [
@@ -33,25 +29,16 @@ AC_DEFUN([ZFS_AC_CONFIG_ALWAYS_PYTHON], [
 	PYTHON_MINOR=${PYTHON_VERSION#*\.}
 
 	AS_CASE([$PYTHON_VERSION],
-		[2.*], [
-			AS_IF([test $PYTHON_MINOR -lt 6],
-				[AC_MSG_ERROR("Python >= 2.6 is required")])
-		],
 		[3.*], [
-			AS_IF([test $PYTHON_MINOR -lt 4],
+			AS_IF([test $PYTHON_MINOR -lt 6],
-				[AC_MSG_ERROR("Python >= 3.4 is required")])
+				[AC_MSG_ERROR("Python >= 3.6 is required")])
 		],
 		[:|2|3], [],
 		[PYTHON_VERSION=3]
 	)
 
 	AM_CONDITIONAL([USING_PYTHON], [test "$PYTHON" != :])
-	AM_CONDITIONAL([USING_PYTHON_2], [test "x${PYTHON_VERSION%%\.*}" = x2])
+	AC_SUBST([PYTHON_SHEBANG], [python3])
-	AM_CONDITIONAL([USING_PYTHON_3], [test "x${PYTHON_VERSION%%\.*}" = x3])
-
-	AM_COND_IF([USING_PYTHON_2],
-		[AC_SUBST([PYTHON_SHEBANG], [python2])],
-		[AC_SUBST([PYTHON_SHEBANG], [python3])])
 
 	dnl #
 	dnl # Request that packages be built for a specific Python version.

config/always-pyzfs.m4

@@ -18,7 +18,7 @@ AC_DEFUN([ZFS_AC_PYTHON_MODULE], [
 ])
 
 dnl #
-dnl # Determines if pyzfs can be built, requires Python 2.7 or later.
+dnl # Determines if pyzfs can be built, requires Python 3.6 or later.
 dnl #
 AC_DEFUN([ZFS_AC_CONFIG_ALWAYS_PYZFS], [
 	AC_ARG_ENABLE([pyzfs],
@@ -62,12 +62,11 @@ AC_DEFUN([ZFS_AC_CONFIG_ALWAYS_PYZFS], [
 	])
 
 	dnl #
-	dnl # Require python-devel libraries
+	dnl # Require python3-devel libraries
 	dnl #
 	AS_IF([test "x$enable_pyzfs" = xcheck  -o "x$enable_pyzfs" = xyes], [
 		AS_CASE([$PYTHON_VERSION],
-			[3.*], [PYTHON_REQUIRED_VERSION=">= '3.4.0'"],
+			[3.*], [PYTHON_REQUIRED_VERSION=">= '3.6.0'"],
-			[2.*], [PYTHON_REQUIRED_VERSION=">= '2.7.0'"],
 			[AC_MSG_ERROR("Python $PYTHON_VERSION unknown")]
 		)
 

contrib/pyzfs/setup.py.in

@@ -29,13 +29,12 @@ setup(
         "Development Status :: 4 - Beta",
         "Intended Audience :: Developers",
         "License :: OSI Approved :: Apache Software License",
-        "Programming Language :: Python :: 2",
-        "Programming Language :: Python :: 2.7",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.4",
-        "Programming Language :: Python :: 3.5",
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
+        "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
+        "Programming Language :: Python :: 3.10",
         "Topic :: System :: Filesystems",
         "Topic :: Software Development :: Libraries",
     ],
@@ -53,7 +52,7 @@ setup(
     setup_requires=[
         "cffi",
     ],
-    python_requires='>=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,<4',
+    python_requires='>=3.6,<4',
     zip_safe=False,
     test_suite="libzfs_core.test",
 )

rpm/generic/zfs.spec.in

@@ -3,7 +3,7 @@
 
 # Set the default udev directory based on distribution.
 %if %{undefined _udevdir}
-%if 0%{?fedora} >= 17 || 0%{?rhel} >= 7 || 0%{?centos} >= 7
+%if 0%{?fedora}%{?rhel}%{?centos}
 %global _udevdir    %{_prefix}/lib/udev
 %else
 %global _udevdir    /lib/udev
@@ -12,7 +12,7 @@
 
 # Set the default udevrule directory based on distribution.
 %if %{undefined _udevruledir}
-%if 0%{?fedora} >= 17 || 0%{?rhel} >= 7 || 0%{?centos} >= 7
+%if 0%{?fedora}%{?rhel}%{?centos}
 %global _udevruledir    %{_prefix}/lib/udev/rules.d
 %else
 %global _udevruledir    /lib/udev/rules.d
@@ -21,7 +21,7 @@
 
 # Set the default dracut directory based on distribution.
 %if %{undefined _dracutdir}
-%if 0%{?fedora} >= 17 || 0%{?rhel} >= 7 || 0%{?centos} >= 7
+%if 0%{?fedora}%{?rhel}%{?centos}
 %global _dracutdir  %{_prefix}/lib/dracut
 %else
 %global _dracutdir  %{_prefix}/share/dracut
@@ -57,59 +57,28 @@
 %bcond_with    asan
 %bcond_with    systemd
 %bcond_with    pam
+%bcond_without pyzfs
 
 # Generic enable switch for systemd
 %if %{with systemd}
 %define _systemd 1
 %endif
 
-# RHEL >= 7 comes with systemd
+# Distros below support systemd
-%if 0%{?rhel} >= 7
+%if 0%{?rhel}%{?fedora}%{?centos}%{?suse_version}
 %define _systemd 1
 %endif
 
-# Fedora >= 15 comes with systemd, but only >= 18 has
+# When not specified default to distribution provided version.
-# the proper macros
-%if 0%{?fedora} >= 18
-%define _systemd 1
-%endif
-
-# opensuse >= 12.1 comes with systemd, but only >= 13.1
-# has the proper macros
-%if 0%{?suse_version} >= 1310
-%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
-%define __python_setuptools_pkg   python-setuptools
-%else
 %define __python                  /usr/bin/python3
 %define __python_pkg_version      3
-%define __python_cffi_pkg         python3-cffi
-%define __python_setuptools_pkg   python3-setuptools
-%endif
 %else
 %define __python                  %{__use_python}
 %define __python_pkg_version      %{__use_python_pkg_version}
-%define __python_cffi_pkg         python%{__python_pkg_version}-cffi
-%define __python_setuptools_pkg   python%{__python_pkg_version}-setuptools
 %endif
 %define __python_sitelib          %(%{__python} -Esc "from distutils.sysconfig import get_python_lib; print(get_python_lib())")
 
-# 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}
@@ -132,7 +101,7 @@ Obsoletes:      spl
 # Renaming those on either side would conflict with all available documentation.
 Conflicts:      zfs-fuse
 
-%if 0%{?rhel}%{?fedora}%{?suse_version}
+%if 0%{?rhel}%{?centos}%{?fedora}%{?suse_version}
 BuildRequires:  gcc, make
 BuildRequires:  zlib-devel
 BuildRequires:  libuuid-devel
@@ -144,7 +113,7 @@ BuildRequires:  openssl-devel
 # crash+corrupt rpmdb
 # See issue #12071
 BuildRequires:  ncompress
-%if 0%{?fedora} >= 28 || 0%{?rhel} >= 8 || 0%{?centos} >= 8
+%if 0%{?fedora} || 0%{?rhel} >= 8 || 0%{?centos} >= 8
 BuildRequires:  libtirpc-devel
 %endif
 
@@ -277,7 +246,7 @@ Requires:       sudo
 Requires:       sysstat
 Requires:       libaio
 Requires:       python%{__python_pkg_version}
-%if 0%{?rhel}%{?fedora}%{?suse_version}
+%if 0%{?rhel}%{?centos}%{?fedora}%{?suse_version}
 BuildRequires:  libaio-devel
 %endif
 AutoReqProv:    no
@@ -300,6 +269,8 @@ This package contains a dracut module used to construct an initramfs
 image which is ZFS aware.
 
 %if %{with pyzfs}
+# Enforce `python36-` package prefix for CentOS 7
+# since dependencies come from EPEL and are named this way
 %package -n python%{__python_pkg_version}-pyzfs
 Summary:        Python %{python_version} wrapper for libzfs_core
 Group:          Development/Languages/Python
@@ -309,16 +280,26 @@ Requires:       libzfs5 = %{version}
 Requires:       libnvpair3 = %{version}
 Requires:       libffi
 Requires:       python%{__python_pkg_version}
-Requires:       %{__python_cffi_pkg}
+
-%if 0%{?rhel}%{?fedora}%{?suse_version}
+%if 0%{?centos} == 7
-%if 0%{?rhel} >= 8 || 0%{?centos} >= 8 || 0%{?fedora} >= 28
+Requires:       python36-cffi
-BuildRequires:  python3-packaging
 %else
-BuildRequires:  python-packaging
+Requires:       python%{__python_pkg_version}-cffi
 %endif
+
+%if 0%{?rhel}%{?centos}%{?fedora}%{?suse_version}
+%if 0%{?centos} == 7
+BuildRequires:  python36-packaging
+BuildRequires:  python36-devel
+BuildRequires:  python36-cffi
+BuildRequires:  python36-setuptools
+%else
+BuildRequires:  python%{__python_pkg_version}-packaging
 BuildRequires:  python%{__python_pkg_version}-devel
-BuildRequires:  %{__python_cffi_pkg}
+BuildRequires:  python%{__python_pkg_version}-cffi
-BuildRequires:  %{__python_setuptools_pkg}
+BuildRequires:  python%{__python_pkg_version}-setuptools
+%endif
+
 BuildRequires:  libffi-devel
 %endif
 
@@ -478,7 +459,7 @@ systemctl --system daemon-reload >/dev/null || true
 %{_bindir}/raidz_test
 %{_sbindir}/zgenhostid
 %{_bindir}/zvol_wait
-# Optional Python 2/3 scripts
+# Optional Python 3 scripts
 %{_bindir}/arc_summary
 %{_bindir}/arcstat
 %{_bindir}/dbufstat

tests/test-runner/bin/test-runner.py.in

@@ -15,19 +15,14 @@
 # Copyright (c) 2012, 2018 by Delphix. All rights reserved.
 # Copyright (c) 2019 Datto Inc.
 #
-# This script must remain compatible with Python 2.6+ and Python 3.4+.
+# This script must remain compatible with Python 3.6+.
 #
 
-# some python 2.7 system don't have a configparser shim
-try:
-    import configparser
-except ImportError:
-    import ConfigParser as configparser
-
 import os
 import sys
 import ctypes
 import re
+import configparser
 
 from datetime import datetime
 from optparse import OptionParser
@@ -37,7 +32,7 @@ from select import select
 from subprocess import PIPE
 from subprocess import Popen
 from threading import Timer
-from time import time
+from time import time, CLOCK_MONOTONIC_RAW
 
 BASEDIR = '/var/tmp/test_results'
 TESTDIR = '/usr/share/zfs/'
@@ -49,9 +44,6 @@ LOG_OUT = 'LOG_OUT'
 LOG_ERR = 'LOG_ERR'
 LOG_FILE_OBJ = None
 
-# some python 2.7 system don't have a concept of monotonic time
-CLOCK_MONOTONIC_RAW = 4  # see <linux/time.h>
-
 
 class timespec(ctypes.Structure):
     _fields_ = [

tests/test-runner/bin/zts-report.py.in

@@ -15,7 +15,7 @@
 # Copyright (c) 2017 by Delphix. All rights reserved.
 # Copyright (c) 2018 by Lawrence Livermore National Security, LLC.
 #
-# This script must remain compatible with Python 2.6+ and Python 3.4+.
+# This script must remain compatible with Python 3.6+.
 #
 
 import os
@@ -62,13 +62,13 @@ known_reason = 'Known issue'
 exec_reason = 'Test user execute permissions required for utilities'
 
 #
-# Some tests require a minimum python version of 3.5 and will be skipped when
+# Some tests require a minimum python version of 3.6 and will be skipped when
 # the default system version is too old.  There may also be tests which require
-# additional python modules be installed, for example python-cffi is required
+# additional python modules be installed, for example python3-cffi is required
 # by the pyzfs tests.
 #
-python_reason = 'Python v3.5 or newer required'
+python_reason = 'Python v3.6 or newer required'
-python_deps_reason = 'Python modules missing: python-cffi'
+python_deps_reason = 'Python modules missing: python3-cffi'
 
 #
 # Some tests require the O_TMPFILE flag which was first introduced in the

tests/zfs-tests/include/commands.cfg

@@ -71,8 +71,6 @@ export SYSTEM_FILES_COMMON='arp
     printf
     ps
     pwd
-    python
-    python2
     python3
     quotaon
     readlink

tests/zfs-tests/tests/functional/cli_root/zfs_program/zfs_program_json.ksh

@@ -92,27 +92,13 @@ typeset -a pos_cmds_out=(
     }
 }")
 
-#
-# N.B. json.tool is needed to guarantee consistent ordering of fields,
-# sed is needed to trim trailing space in CentOS 6's json.tool output
-#
-# As of Python 3.5 the behavior of json.tool changed to keep the order
-# the same as the input and the --sort-keys option was added.  Detect when
-# --sort-keys is supported and apply the option to ensure the expected order.
-#
-if python -m json.tool --sort-keys <<< "{}"; then
-	JSON_TOOL_CMD="python -m json.tool --sort-keys"
-else
-	JSON_TOOL_CMD="python -m json.tool"
-fi
-
 typeset -i cnt=0
 typeset cmd
 for cmd in ${pos_cmds[@]}; do
 	log_must zfs program $TESTPOOL $TESTZCP $TESTDS $cmd 2>&1
 	log_must zfs program -j $TESTPOOL $TESTZCP $TESTDS $cmd 2>&1
 	OUTPUT=$(zfs program -j $TESTPOOL $TESTZCP $TESTDS $cmd 2>&1 |
-	    $JSON_TOOL_CMD | sed 's/[[:space:]]*$//')
+	    python3 -m json.tool --sort-keys)
 	if [ "$OUTPUT" != "${pos_cmds_out[$cnt]}" ]; then
 		log_note "Got     :$OUTPUT"
 		log_note "Expected:${pos_cmds_out[$cnt]}"

tests/zfs-tests/tests/functional/pyzfs/pyzfs_unittest.ksh.in

@@ -30,7 +30,7 @@ verify_runnable "global"
 # Verify that the required dependencies for testing are installed.
 @PYTHON@ -c "import cffi" 2>/dev/null
 if [ $? -eq 1 ]; then
-	log_unsupported "python-cffi not found by Python"
+	log_unsupported "python3-cffi not found by Python"
 fi
 
 # We don't just try to "import libzfs_core" because we want to skip these tests

tests/zfs-tests/tests/functional/rsend/send_encrypted_files.ksh

@@ -87,7 +87,7 @@ log_must xattrtest -f 10 -x 3 -s 32768 -r -k -p /$TESTPOOL/$TESTFS2/xattrsadir
 # OpenZFS issue #7432
 log_must zfs set compression=on xattr=sa $TESTPOOL/$TESTFS2
 log_must touch /$TESTPOOL/$TESTFS2/attrs
-log_must eval "python -c 'print \"a\" * 4096' | \
+log_must eval "python3 -c 'print \"a\" * 4096' | \
 	set_xattr_stdin bigval /$TESTPOOL/$TESTFS2/attrs"
 log_must zfs set compression=off xattr=on $TESTPOOL/$TESTFS2
 

tests/zfs-tests/tests/functional/rsend/send_realloc_dnode_size.ksh

@@ -88,7 +88,7 @@ log_must zfs snapshot $POOL/fs@c
 # 4. Create an empty file and add xattrs to it to exercise reclaiming a
 #    dnode that requires more than 1 slot for its bonus buffer (Zol #7433)
 log_must zfs set compression=on xattr=sa $POOL/fs
-log_must eval "python -c 'print \"a\" * 512' |
+log_must eval "python3 -c 'print \"a\" * 512' |
     set_xattr_stdin bigval /$POOL/fs/attrs"
 log_must zfs snapshot $POOL/fs@d