Support proper semver ranges for Helm charts

This commit changes the semver range parser to `blang/semver`, which
is also used to parse semver tags for GitRepository sources.

Author: hiddeco

config/samples/source_v1alpha1_helmchart.yaml

@@ -4,7 +4,7 @@ metadata:
   name: helmchart-sample
 spec:
   name: podinfo
-  version: '^2.0.0'
+  version: '>=2.0.0 <3.0.0'
   helmRepositoryRef:
     name: helmrepository-sample
   interval: 1m

controllers/helmchart_controller.go

@@ -26,7 +26,6 @@ import (
 
 	"github.com/go-logr/logr"
 	"helm.sh/helm/v3/pkg/getter"
-	"helm.sh/helm/v3/pkg/repo"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
@@ -36,9 +35,9 @@ import (
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/controller-runtime/pkg/controller"
-	"sigs.k8s.io/yaml"
 
 	"github.com/fluxcd/pkg/recorder"
+
 	sourcev1 "github.com/fluxcd/source-controller/api/v1alpha1"
 	"github.com/fluxcd/source-controller/internal/helm"
 )
@@ -174,30 +173,8 @@ func (r *HelmChartReconciler) SetupWithManagerAndOptions(mgr ctrl.Manager, opts
 }
 
 func (r *HelmChartReconciler) reconcile(ctx context.Context, repository sourcev1.HelmRepository, chart sourcev1.HelmChart) (sourcev1.HelmChart, error) {
-	indexBytes, err := ioutil.ReadFile(repository.Status.Artifact.Path)
-	if err != nil {
-		err = fmt.Errorf("failed to read Helm repository index file: %w", err)
-		return sourcev1.HelmChartNotReady(chart, sourcev1.StorageOperationFailedReason, err.Error()), err
-	}
-	index := &repo.IndexFile{}
-	if err := yaml.Unmarshal(indexBytes, index); err != nil {
-		return sourcev1.HelmChartNotReady(chart, sourcev1.StorageOperationFailedReason, err.Error()), err
-	}
-
-	// find referenced chart in index
-	cv, err := index.Get(chart.Spec.Name, chart.Spec.Version)
+	cv, err := helm.GetDownloadableChartVersionFromIndex(repository.Status.Artifact.Path, chart.Spec.Name, chart.Spec.Version)
 	if err != nil {
-		switch err {
-		case repo.ErrNoChartName:
-			err = fmt.Errorf("chart '%s' could not be found in Helm repository '%s'", chart.Spec.Name, repository.Name)
-		case repo.ErrNoChartVersion:
-			err = fmt.Errorf("no chart with version '%s' found for '%s'", chart.Spec.Version, chart.Spec.Name)
-		}
-		return sourcev1.HelmChartNotReady(chart, sourcev1.ChartPullFailedReason, err.Error()), err
-	}
-
-	if len(cv.URLs) == 0 {
-		err = fmt.Errorf("chart '%s' has no downloadable URLs", cv.Name)
 		return sourcev1.HelmChartNotReady(chart, sourcev1.ChartPullFailedReason, err.Error()), err
 	}
 
@@ -207,7 +184,6 @@ func (r *HelmChartReconciler) reconcile(ctx context.Context, repository sourcev1
 	u, err := url.Parse(ref)
 	if err != nil {
 		err = fmt.Errorf("invalid chart URL format '%s': %w", ref, err)
-		return sourcev1.HelmChartNotReady(chart, sourcev1.ChartPullFailedReason, err.Error()), err
 	}
 
 	c, err := r.Getters.ByScheme(u.Scheme)

controllers/helmchart_controller_test.go

@@ -101,7 +101,7 @@ var _ = Describe("HelmChartReconciler", func() {
 				},
 				Spec: sourcev1.HelmChartSpec{
 					Name:              "helmchart",
-					Version:           "*",
+					Version:           "",
 					HelmRepositoryRef: corev1.LocalObjectReference{Name: repositoryKey.Name},
 					Interval:          metav1.Duration{Duration: pullInterval},
 				},
@@ -203,7 +203,6 @@ var _ = Describe("HelmChartReconciler", func() {
 				},
 				Spec: sourcev1.HelmChartSpec{
 					Name:              "helmchart",
-					Version:           "*",
 					HelmRepositoryRef: corev1.LocalObjectReference{Name: repositoryKey.Name},
 					Interval:          metav1.Duration{Duration: 1 * time.Hour},
 				},
@@ -218,7 +217,7 @@ var _ = Describe("HelmChartReconciler", func() {
 				return ""
 			}, timeout, interval).Should(Equal("1.0.0"))
 
-			chart.Spec.Version = "~0.1.0"
+			chart.Spec.Version = "<0.2.0"
 			Expect(k8sClient.Update(context.Background(), chart)).Should(Succeed())
 			Eventually(func() string {
 				_ = k8sClient.Get(context.Background(), key, chart)

internal/helm/repository.go

@@ -0,0 +1,80 @@
+/*
+Copyright 2020 The Flux CD contributors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package helm
+
+import (
+	"fmt"
+	"io/ioutil"
+
+	"github.com/blang/semver"
+	"helm.sh/helm/v3/pkg/repo"
+	"sigs.k8s.io/yaml"
+)
+
+func GetDownloadableChartVersionFromIndex(path, chart, version string) (*repo.ChartVersion, error) {
+	b, err := ioutil.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read Helm repository index file: %w", err)
+	}
+	index := &repo.IndexFile{}
+	if err := yaml.Unmarshal(b, index); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal Helm repository index file: %w", err)
+	}
+
+	var cv *repo.ChartVersion
+	if version == "" || version == "*" {
+		cv, err = index.Get(chart, version)
+		if err != nil {
+			if err == repo.ErrNoChartName {
+				err = fmt.Errorf("chart '%s' could not be found in Helm repository index", chart)
+			}
+			return nil, err
+		}
+	} else {
+		entries, ok := index.Entries[chart]
+		if !ok {
+			return nil, fmt.Errorf("chart '%s' could not be found in Helm repository index", chart)
+		}
+
+		rng, err := semver.ParseRange(version)
+		if err != nil {
+			return nil, fmt.Errorf("semver range parse error: %w", err)
+		}
+		versionEntryLookup := make(map[string]*repo.ChartVersion)
+		var versionsInRange []semver.Version
+		for _, e := range entries {
+			v, _ := semver.ParseTolerant(e.Version)
+			if rng(v) {
+				versionsInRange = append(versionsInRange, v)
+				versionEntryLookup[v.String()] = e
+			}
+		}
+		if len(versionsInRange) == 0 {
+			return nil, fmt.Errorf("no match found for semver: %s", version)
+		}
+		semver.Sort(versionsInRange)
+
+		latest := versionsInRange[len(versionsInRange)-1]
+		cv = versionEntryLookup[latest.String()]
+	}
+
+	if len(cv.URLs) == 0 {
+		return nil, fmt.Errorf("no downloadable URLs for chart '%s' with version '%s'", cv.Name, cv.Version)
+	}
+
+	return cv, nil
+}