Remove use of rpmUtils.miscutils from cgcs-patch

The rpmUtils.miscutils.stringToVersion function will not be available
in CentOS8, as it is not currently provided for python3. A similar
function exists in cgcs_patch.patch_functions, using regex to parse
the version from an RPM filename. This update adds a new function,
expand_pkgver, implemented in a similar fashion using regex, providing
the same capability as rpmUtils.miscutils.stringToVersion.

Change-Id: I2a04f3dbf85d62c87ca1afcf988b672aafceb642
Story: 2006228
Task: 37871
Signed-off-by: Don Penney <don.penney@windriver.com>

cgcs-patch/cgcs-patch/cgcs_patch/patch_agent.py

@@ -19,9 +19,8 @@ import sys
 import yaml
 import shutil
 
-from rpmUtils.miscutils import stringToVersion  # pylint: disable=import-error
-
 from cgcs_patch.patch_functions import configure_logging
+from cgcs_patch.patch_functions import parse_pkgver
 from cgcs_patch.patch_functions import LOG
 import cgcs_patch.config as cfg
 from cgcs_patch.base import PatchService
@@ -519,8 +518,8 @@ class PatchAgent(PatchService):
                 #     1, if first arg is higher version
                 #     0, if versions are same
                 #     -1, if first arg is lower version
-                rc = rpm.labelCompare(stringToVersion(version),
-                                      stringToVersion(stored_ver))
+                rc = rpm.labelCompare(parse_pkgver(version),
+                                      parse_pkgver(stored_ver))
 
                 if rc > 0:
                     # Update version
@@ -709,8 +708,8 @@ class PatchAgent(PatchService):
                     compare_version = base_version
 
                 # Compare the installed version to what's in the repo
-                rc = rpm.labelCompare(stringToVersion(installed_version),
-                                      stringToVersion(compare_version))
+                rc = rpm.labelCompare(parse_pkgver(installed_version),
+                                      parse_pkgver(compare_version))
                 if rc == 0:
                     # Versions match, nothing to do.
                     continue

cgcs-patch/cgcs-patch/cgcs_patch/patch_controller.py

@@ -17,7 +17,7 @@ import rpm
 import os
 import gc
 
-from rpmUtils.miscutils import stringToVersion  # pylint: disable=import-error
+from cgcs_patch.patch_functions import parse_pkgver
 
 from wsgiref import simple_server
 from cgcs_patch.api import app
@@ -776,8 +776,8 @@ class PatchController(PatchService):
                         # Ignore epoch
                         patch_ver = patch_ver.split(':')[1]
 
-                    rc = rpm.labelCompare(stringToVersion(installed_ver),
-                                          stringToVersion(patch_ver))
+                    rc = rpm.labelCompare(parse_pkgver(installed_ver),
+                                          parse_pkgver(patch_ver))
 
                     if self.patch_data.metadata[patch_id]["repostate"] == constants.AVAILABLE:
                         # The RPM is not expected to be installed.

cgcs-patch/cgcs-patch/cgcs_patch/patch_functions.py

@@ -176,6 +176,24 @@ def parse_rpm_filename(filename):
     return (pkgname, arch, PackageVersion(epoch, version, release))
 
 
+def parse_pkgver(pkgver):
+    # Version format is:
+    # [<epoch>:]<version>-<release>
+    #
+    pattern = re.compile(r'((([^:]):)?)([^-]+)((-(.*))?)$')
+
+    m = pattern.match(pkgver)
+
+    if m is None:
+        raise ValueError("Package version does not match expected format: %s" % pkgver)
+
+    epoch = m.group(3)
+    version = m.group(4)
+    release = m.group(7)
+
+    return (epoch, version, release)
+
+
 class PackageVersion(object):
     """
     The PackageVersion class provides a structure for RPM version information,

cgcs-patch/cgcs-patch/cgcs_patch/tests/test_patch_agent.py

@@ -10,8 +10,6 @@ import sys
 import testtools
 
 sys.modules['rpm'] = mock.Mock()
-sys.modules['rpmUtils'] = mock.Mock()
-sys.modules['rpmUtils.miscutils'] = mock.Mock()
 
 import cgcs_patch.patch_agent  # noqa: E402
 

cgcs-patch/cgcs-patch/cgcs_patch/tests/test_patch_controller.py

@@ -10,8 +10,6 @@ import sys
 import testtools
 
 sys.modules['rpm'] = mock.Mock()
-sys.modules['rpmUtils'] = mock.Mock()
-sys.modules['rpmUtils.miscutils'] = mock.Mock()
 
 import cgcs_patch.patch_controller  # noqa: E402
 

cgcs-patch/cgcs-patch/cgcs_patch/tests/test_patch_utils.py

@@ -9,6 +9,7 @@ import socket
 import testtools
 
 import cgcs_patch.constants
+import cgcs_patch.patch_functions
 import cgcs_patch.utils
 
 
@@ -130,3 +131,16 @@ class CgcsPatchUtilsTestCase(testtools.TestCase):
 
         result = cgcs_patch.utils.ip_to_versioned_localhost(ip)
         self.assertEqual(expected_result, result)
+
+    def test_parse_pkgver(self):
+        versions = {
+            '0:1.2.3-r4': ('0', '1.2.3', 'r4'),
+            '4.3.2-1': (None, '4.3.2', '1'),
+            '8.1.4': (None, '8.1.4', None),
+            '5:7.5.3': ('5', '7.5.3', None),
+            'This is a weird version string': (None, 'This is a weird version string', None),
+        }
+
+        for ver, expected in versions.items():
+            result = cgcs_patch.patch_functions.parse_pkgver(ver)
+            self.assertEqual(result, expected)