pungi-koji: Allow user to specify version component count in latest symlink

This change adds an option which allows users to specify
the number of version components (i.e. values between dots)

The default behavior is preserved, and is equivalent to using
'-1' as the value.

- Negative values remove items from the end.
- Positive values specify the count of of components
- Zero will remove the version field entirely from the symlink
- When nonzero, at least one version component will appear

Merges: https://pagure.io/pungi/pull-request/1361
Signed-off-by: Lon Hohberger <lhh@redhat.com>

pungi/scripts/pungi_koji.py

@@ -151,6 +151,12 @@ def main():
         default=[],
         help="only create latest symbol link to this compose when compose status matches specified status",  # noqa: E501
     )
+    parser.add_argument(
+        "--latest-link-components",
+        type=int,
+        default=-1,
+        help="number of product version components used when creating latest symlink",  # noqa: E501
+    )
     parser.add_argument(
         "--print-output-dir",
         action="store_true",
@@ -203,6 +209,7 @@ def main():
 
     create_latest_link = not opts.no_latest_link
     latest_link_status = opts.latest_link_status or None
+    latest_link_components = opts.latest_link_components
 
     import kobo.conf
     import kobo.log
@@ -289,10 +296,13 @@ def main():
         compose,
         create_latest_link=create_latest_link,
         latest_link_status=latest_link_status,
+        latest_link_components=latest_link_components,
     )
 
 
-def run_compose(compose, create_latest_link=True, latest_link_status=None):
+def run_compose(
+    compose, create_latest_link=True, latest_link_status=None, latest_link_components=-1
+):
     import pungi.phases
     import pungi.metadata
     import pungi.util
@@ -501,15 +511,19 @@ def run_compose(compose, create_latest_link=True, latest_link_status=None):
 
     if latest_link:
         compose_dir = os.path.basename(compose.topdir)
-        if len(compose.conf["release_version"].split(".")) == 1:
-            symlink_name = "latest-%s-%s" % (
-                compose.conf["release_short"],
-                compose.conf["release_version"],
-            )
+        # Omit version entirely if latest_link_components == 0
+        if latest_link_components == 0:
+            symlink_name = "latest-%s" % compose.conf["release_short"]
         else:
+            hunks = compose.conf["release_version"].split(".")
+            # Set up our min/max so we don't overrun our array
+            if latest_link_components > 0:
+                latest_link_components = min(len(hunks), latest_link_components)
+            else:
+                latest_link_components = max(1, len(hunks) + latest_link_components)
             symlink_name = "latest-%s-%s" % (
                 compose.conf["release_short"],
-                ".".join(compose.conf["release_version"].split(".")[:-1]),
+                ".".join(hunks[:latest_link_components]),
             )
         if compose.conf.get("base_product_name", ""):
             symlink_name += "-%s-%s" % (