globally replace pkg_resources.parse_version with non-aliased class

For a long time now, pkg_resources has depended on a (possibly vendored)
copy of the packaging module, and imports `Version` as `parse_version`.

Use the original class directly. Add a direct dependency on packaging to
make sure it's visibly required.

pkg_resources is deprecated and the recommended replacement is to
directly use packaging where relevant. The result is faster to load, and
more guaranteed to work e.g. in environments where setuptools isn't
installed by default.

pifpaf/drivers/ceph.py

@@ -14,7 +14,7 @@
 import os
 import uuid
 
-import pkg_resources
+import packaging
 
 from pifpaf import drivers
 
@@ -51,9 +51,9 @@ def _setUp(self):
 
         _, version = self._exec(["ceph", "--version"], stdout=True)
         version = version.decode("ascii").split()[2]
-        version = pkg_resources.parse_version(version)
+        version = packaging.version.Version(version)
 
-        if version < pkg_resources.parse_version("12.0.0"):
+        if version < packaging.version.Version("12.0.0"):
             extra = """
 mon_osd_nearfull_ratio = 1
 mon_osd_full_ratio = 1
@@ -66,7 +66,7 @@ def _setUp(self):
 """
 
         # Enable msgrv2 protocol if Nautilus or later.
-        if version >= pkg_resources.parse_version("14.0.0"):
+        if version >= packaging.version.Version("14.0.0"):
             msgrv2_extra = """
 mon_host = v2:127.0.0.1:%(port)d/0
 """ % dict(port=self.port)
@@ -156,7 +156,7 @@ def _setUp(self):
             wait_for_line=r"mon.a@0\(leader\).mds e1 print_map")
 
         # Start manager
-        if version >= pkg_resources.parse_version("12.0.0"):
+        if version >= packaging.version.Version("12.0.0"):
             self._exec(
                 mgr_opts,
                 wait_for_line="(mgr send_beacon active|waiting for OSDs)")
@@ -166,13 +166,13 @@ def _setUp(self):
         self._exec(ceph_opts + ["osd", "crush", "add", "osd.0", "1",
                                 "root=default"])
         self._exec(osd_opts + ["--mkfs", "--mkjournal"])
-        if version < pkg_resources.parse_version("0.94.0"):
+        if version < packaging.version.Version("0.94.0"):
             wait_for_line = "journal close"
         else:
             wait_for_line = "done with init"
         osd, _ = self._exec(osd_opts, wait_for_line=wait_for_line)
 
-        if version >= pkg_resources.parse_version("12.0.0"):
+        if version >= packaging.version.Version("12.0.0"):
             self._exec(ceph_opts + ["osd", "set-full-ratio", "0.95"])
             self._exec(ceph_opts + ["osd", "set-backfillfull-ratio", "0.95"])
             self._exec(ceph_opts + ["osd", "set-nearfull-ratio", "0.95"])

setup.cfg

@@ -25,6 +25,7 @@ install_requires =
     click
     jinja2
     fixtures
+    packaging
     psutil
     xattr ; sys_platform != 'win32'