root: fix compose generation for patch releases release candidates (#21353)

* root: fix compose generation for patch releases release candidates

Signed-off-by: Marc 'risson' Schmitt <marc.schmitt@risson.space>

* add comment

Signed-off-by: Marc 'risson' Schmitt <marc.schmitt@risson.space>

---------

Signed-off-by: Marc 'risson' Schmitt <marc.schmitt@risson.space>

scripts/generate_compose.py

@@ -1,12 +1,21 @@
 #!/usr/bin/env python3
 
+from packaging.version import parse
 from yaml import safe_dump
 
 from authentik import authentik_version
 
-authentik_image = (
+version = authentik_version()
-    f"${{AUTHENTIK_IMAGE:-ghcr.io/goauthentik/server}}:${{AUTHENTIK_TAG:-{authentik_version()}}}"
+version_parsed = parse(version)
-)
+version_split = version_parsed.base_version.split(".")
+# If this is an rc version for a patch release (i.e. 2026.2.2-rc1), then don't include that in the
+# compose, and fallback to the previous released patch version
+if version_parsed.is_prerelease and version_split[-1] != "0":
+    previous_patch = int(version_split[-1]) - 1
+    version_split[-1] = str(previous_patch)
+    version = ".".join(version_split)
+
+authentik_image = f"${{AUTHENTIK_IMAGE:-ghcr.io/goauthentik/server}}:${{AUTHENTIK_TAG:-{version}}}"
 
 base = {
     "services": {