Refactored gen_yum_config_file function with common defaults

and required fields.

All references updated and tests passing:

```bash
$ git grep 'gen_yum_config_file('
pulp_2_tests/tests/rpm/api_v2/test_errata.py:        repo_path = gen_yum_config_file(
pulp_2_tests/tests/rpm/api_v2/test_modularity.py:        repo_path = gen_yum_config_file(
pulp_2_tests/tests/rpm/api_v2/test_rich_weak_dependencies.py:        repo_path = gen_yum_config_file(
pulp_2_tests/tests/rpm/cli/test_copy_units.py:        repo_path = gen_yum_config_file(

$ py.test --pyargs $(git grep 'gen_yum_config_file(')
collected 4 items
pulp_2_tests/tests/rpm/api_v2/test_errata.py::ApplyErratumTestCase::test_all PASSED
pulp_2_tests/tests/rpm/api_v2/test_modularity.py::PackageManagerModuleListTestCase::test_all PASSED
pulp_2_tests/tests/rpm/api_v2/test_rich_weak_dependencies.py::PackageManagerCosumeRPMTestCase::test_all PASSED
pulp_2_tests/tests/rpm/cli/test_copy_units.py::UpdateRpmTestCase::test_all PASSED
```

pulp_2_tests/tests/rpm/api_v2/test_errata.py

@@ -75,7 +75,6 @@ def _create_repo_file(self, cfg, repo):
 
         Also, schedule it for deletion. Return nothing.
         """
-        verify = cfg.get_hosts('api')[0].roles['api'].get('verify')
         sudo = () if cli.is_root(cfg) else ('sudo',)
         repo_path = gen_yum_config_file(
             cfg,
@@ -84,11 +83,7 @@ def _create_repo_file(self, cfg, repo):
                 repo['distributors'][0]['config']['relative_url']
             )),
             name=repo['_href'],
-            enabled=1,
-            gpgcheck=0,
-            metadata_expire=0,  # force metadata to load every time
-            repositoryid=repo['id'],
-            sslverify='yes' if verify else 'no',
+            repositoryid=repo['id']
         )
         self.addCleanup(cli.Client(cfg).run, sudo + ('rm', repo_path))
 

pulp_2_tests/tests/rpm/api_v2/test_modularity.py

@@ -181,7 +181,6 @@ def test_all(self):
         sync_repo(cfg, repo)
         publish_repo(cfg, repo)
         repo = client.get(repo['_href'], params={'details': True})
-        verify = cfg.get_hosts('api')[0].roles['api'].get('verify')
         sudo = () if cli.is_root(cfg) else ('sudo',)
         repo_path = gen_yum_config_file(
             cfg,
@@ -190,11 +189,7 @@ def test_all(self):
                 repo['distributors'][0]['config']['relative_url']
             )),
             name=repo['_href'],
-            enabled=1,
-            gpgcheck=0,
-            metadata_expire=0,  # force metadata to load every time
-            repositoryid=repo['id'],
-            sslverify='yes' if verify else 'no',
+            repositoryid=repo['id']
         )
         cli_client = cli.Client(cfg)
         self.addCleanup(cli_client.run, sudo + ('rm', repo_path))

pulp_2_tests/tests/rpm/api_v2/test_rich_weak_dependencies.py

@@ -121,7 +121,6 @@ def test_all(self):
         repo = client.get(repo['_href'], params={'details': True})
         sync_repo(cfg, repo)
         publish_repo(cfg, repo)
-        verify = cfg.get_hosts('api')[0].roles['api'].get('verify')
         sudo = () if cli.is_root(cfg) else ('sudo',)
         repo_path = gen_yum_config_file(
             cfg,
@@ -130,11 +129,7 @@ def test_all(self):
                 repo['distributors'][0]['config']['relative_url']
             )),
             name=repo['_href'],
-            enabled=1,
-            gpgcheck=0,
-            metadata_expire=0,  # force metadata to load every time
-            repositoryid=repo['id'],
-            sslverify='yes' if verify else 'no',
+            repositoryid=repo['id']
         )
         cli_client = cli.Client(cfg)
         self.addCleanup(cli_client.run, sudo + ('rm', repo_path))

pulp_2_tests/tests/rpm/cli/test_copy_units.py

@@ -223,7 +223,6 @@ def test_all(self):
         client = cli.Client(cfg)
         pkg_mgr = cli.PackageManager(cfg)
         sudo = () if cli.is_root(cfg) else ('sudo',)
-        verify = cfg.get_hosts('api')[0].roles['api'].get('verify')
 
         # Create the second repository.
         repo_id = self.create_repo(cfg)
@@ -239,12 +238,8 @@ def test_all(self):
         repo_path = gen_yum_config_file(
             cfg,
             baseurl=urljoin(cfg.get_base_url(), 'pulp/repos/' + repo_id),
-            enabled=1,
-            gpgcheck=0,
-            metadata_expire=0,  # force metadata to load every time
             name=repo_id,
-            repositoryid=repo_id,
-            sslverify='yes' if verify else 'no',
+            repositoryid=repo_id
         )
         self.addCleanup(client.run, sudo + ('rm', repo_path))
         pkg_mgr.install(rpm_name)

pulp_2_tests/tests/rpm/utils.py

@@ -178,7 +178,7 @@ def rpm_rich_weak_dependencies(cfg):
     return Version(response.stdout.split()[2]) >= Version(RPM_PKG_RICH_WEAK_VERSION)
 
 
-def gen_yum_config_file(cfg, repositoryid, **kwargs):
+def gen_yum_config_file(cfg, repositoryid, baseurl, name, **kwargs):
     """Generate a yum configuration file and write it to ``/etc/yum.repos.d/``.
 
     Generate a yum configuration file containing a single repository section,
@@ -189,10 +189,27 @@ def gen_yum_config_file(cfg, repositoryid, **kwargs):
     :param repositoryid: The section's ``repositoryid``. Used when naming the
         configuration file and populating the brackets at the head of the file.
         For details, see yum.conf(5).
+    :param baseurl: The required option ``baseurl`` specifying the url of repo.
+        For details, see yum.conf(5)
+    :param name: The required option ``name`` specifying the name of repo.
+        For details, see yum.conf(5).
     :param kwargs: Section options. Each kwarg corresponds to one option. For
         details, see yum.conf(5).
     :returns: The path to the yum configuration file.
     """
+    # required repo options
+    kwargs.setdefault('name', name)
+    kwargs.setdefault('baseurl', baseurl)
+    # assume some common used defaults
+    kwargs.setdefault('enabled', 1)
+    kwargs.setdefault('gpgcheck', 0)
+    kwargs.setdefault('metadata_expire', 0)  # force metadata load every time
+    # if sslverify is not provided in kwargs it is inferred from cfg
+    kwargs.setdefault(
+        'sslverify',
+        'yes' if cfg.get_hosts('api')[0].roles['api'].get('verify') else 'no'
+    )
+
     path = os.path.join('/etc/yum.repos.d/', repositoryid + '.repo')
     with StringIO() as section:
         section.write('[{}]\n'.format(repositoryid))