Merge pull request #13276 from fabriziopandini/simplify-GetUpgradePlanFromClusterClassVersions

🌱 Simplify GetUpgradePlanFromClusterClassVersions

Author: k8s-ci-robot

exp/topology/desiredstate/upgrade_plan.go

@@ -373,23 +373,30 @@ func GetUpgradePlanFromClusterClassVersions(clusterClassVersions []string) func(
 			return nil, nil, nil
 		}
 
-		// Pick all the known kubernetes versions starting from control plane version (excluded) to desired version.
+		// Pick all the candidate kubernetes versions starting from control plane version (excluded) to desired version.
 		upgradePlan := []string{}
-		start := false
-		end := false
 		for _, v := range clusterClassVersions {
 			semV, err := semver.ParseTolerant(v)
 			if err != nil {
 				return nil, nil, errors.Wrapf(err, "failed to parse version %s", v)
 			}
-			if (start && !end) || (!start && semV.Minor > currentControlPlaneSemVer.Minor) {
-				upgradePlan = append(upgradePlan, v)
+			// Ignore all candidate version older or equal to the current control plane version;
+			// also ignoring same versions but with different build tags, because those version will never
+			// end up in the computed upgrade plan (it starts from the next minor).
+			if version.Compare(semV, currentControlPlaneSemVer) <= 0 {
+				continue
 			}
-			if semV.String() == currentControlPlaneSemVer.String() || version.Compare(currentControlPlaneSemVer, semV, version.WithBuildTags()) < 0 {
-				start = true
+			// Safeguard to stop collecting candidate version when we are past desired version.
+			// Note This should never happen because web hook enforcing that the desired version is in the list of versions.
+			if version.Compare(semV, desiredSemVer, version.WithBuildTags()) == 1 {
+				break
 			}
-			if semV.String() == desiredSemVer.String() || version.Compare(desiredSemVer, semV, version.WithBuildTags()) < 0 {
-				end = true
+
+			upgradePlan = append(upgradePlan, v)
+
+			// Stop collecting candidate version when we arrive at the desired version.
+			if semV.String() == desiredSemVer.String() {
+				break
 			}
 		}
 

exp/topology/desiredstate/upgrade_plan_test.go

@@ -1090,6 +1090,21 @@ func TestGetUpgradePlanFromClusterClassVersions(t *testing.T) {
 			wantWorkersUpgradePlan:      nil,
 			wantErr:                     false,
 		},
+		{
+			name: "version with not sortable build tags",
+			clusterClassVersions: []string{
+				"v1.31.0+a", "v1.31.0+b", "v1.31.0+c", // this is the same minor of currentControlPlaneVersion, everything should be ignored.
+				"v1.31.1+a",
+				"v1.32.0+a", "v1.32.0+b", "v1.32.0+c",
+				"v1.33.0+b",
+				"v1.33.1+a", "v1.33.1+b", "v1.33.1+c", // desiredVersion ends with +b, +c should be ignored.
+			},
+			desiredVersion:              "v1.33.1+b",
+			currentControlPlaneVersion:  "v1.31.0+b",
+			wantControlPlaneUpgradePlan: []string{"v1.32.0+c", "v1.33.1+b"},
+			wantWorkersUpgradePlan:      nil,
+			wantErr:                     false,
+		},
 
 		// Kubernetes versions in CC is set when clusters already exists