release: make --default_brew_tag argument optional

Before this change see --default_brew_tag:

    $ errata-tool release create async --help
    usage: errata-tool release create async [-h] --name NAME --product PRODUCT
                                            --product_version PRODUCT_VERSION
                                            --program_manager PROGRAM_MANAGER
                                            --default_brew_tag DEFAULT_BREW_TAG
                                            [--blocker_flags BLOCKER_FLAGS]

    optional arguments:
      -h, --help            show this help message and exit
      --name NAME           eg. "rhceph-2.4"
      --product PRODUCT     eg. "RHCEPH"
      --product_version PRODUCT_VERSION
                            eg. "RHEL-7-CEPH-3"
      --program_manager PROGRAM_MANAGER
                            eg. "anharris"
      --default_brew_tag DEFAULT_BREW_TAG
                            eg. "ceph-3.0-rhel-7-candidate"
      --blocker_flags BLOCKER_FLAGS
                            eg. "ceph-2.y"

(and respectively for ystream and zstream)

After this change see again --default_brew_tag:

    $ errata-tool release create async --help
    usage: errata-tool release create async [-h] --name NAME --product PRODUCT
                                            --product_version PRODUCT_VERSION
                                            --program_manager PROGRAM_MANAGER
                                            [--default_brew_tag DEFAULT_BREW_TAG]
                                            [--blocker_flags BLOCKER_FLAGS]

    optional arguments:
      -h, --help            show this help message and exit
      --name NAME           eg. "rhceph-2.4"
      --product PRODUCT     eg. "RHCEPH"
      --product_version PRODUCT_VERSION
                            eg. "RHEL-7-CEPH-3"
      --program_manager PROGRAM_MANAGER
                            eg. "anharris"
      --default_brew_tag DEFAULT_BREW_TAG
                            eg. "ceph-3.0-rhel-7-candidate"
      --blocker_flags BLOCKER_FLAGS
                            eg. "ceph-2.y"

(and respectively for ystream and zstream)

Fixes: red-hat-storage#148

errata_tool/cli/release.py

@@ -42,7 +42,7 @@ def add_parser(subparsers):
                             help='eg. "RHEL-7-CEPH-3"')
         parser.add_argument('--program_manager', required=True,
                             help='eg. "anharris"')
-        parser.add_argument('--default_brew_tag', required=True,
+        parser.add_argument('--default_brew_tag',
                             help='eg. "ceph-3.0-rhel-7-candidate"')
 
     for parser in (ystream_create_parser, zstream_create_parser):

errata_tool/tests/cli/test_release_cli.py

@@ -98,6 +98,18 @@ def test_create_ystream_missing_blocker(monkeypatch):
         main.main()
 
 
+def test_create_ystream_missing_default_brew_tag(monkeypatch):
+    monkeypatch.setattr('errata_tool.cli.release.Release', FakeMissingRelease)
+    argv = ['errata-tool', 'release', 'create', 'ystream',
+            '--name', 'rhceph-2.4',
+            '--product', 'RHCEPH',
+            '--product_version', 'RHEL-7-CEPH-2',
+            '--program_manager', 'anharris',
+            '--blocker_flags', 'ceph-2.y']
+    monkeypatch.setattr(sys, 'argv', argv)
+    main.main()
+
+
 def test_create_zstream_missing_args(monkeypatch):
     argv = ['errata-tool', 'release', 'create', 'zstream']
     monkeypatch.setattr(sys, 'argv', argv)
@@ -131,6 +143,18 @@ def test_create_zstream_missing_blocker(monkeypatch):
         main.main()
 
 
+def test_create_zstream_missing_default_brew_tag(monkeypatch):
+    monkeypatch.setattr('errata_tool.cli.release.Release', FakeMissingRelease)
+    argv = ['errata-tool', 'release', 'create', 'zstream',
+            '--name', 'rhceph-2.4',
+            '--product', 'RHCEPH',
+            '--product_version', 'RHEL-7-CEPH-2',
+            '--program_manager', 'anharris',
+            '--blocker_flags', 'ceph-2.y']
+    monkeypatch.setattr(sys, 'argv', argv)
+    main.main()
+
+
 def test_create_async_missing_args(monkeypatch):
     argv = ['errata-tool', 'release', 'create', 'async']
     monkeypatch.setattr(sys, 'argv', argv)
@@ -148,3 +172,15 @@ def test_create_async(monkeypatch):
             '--default_brew_tag', 'ceph-3.0-rhel-7-candidate']
     monkeypatch.setattr(sys, 'argv', argv)
     main.main()
+
+
+def test_create_async_missing_default_brew_tag(monkeypatch):
+    monkeypatch.setattr('errata_tool.cli.release.Release', FakeMissingRelease)
+    argv = ['errata-tool', 'release', 'create', 'async',
+            '--name', 'rhceph-2.4',
+            '--product', 'RHCEPH',
+            '--product_version', 'RHEL-7-CEPH-2',
+            '--program_manager', 'anharris',
+            '--blocker_flags', 'ceph-2.y']
+    monkeypatch.setattr(sys, 'argv', argv)
+    main.main()