do not error for remote chart if there's a missing local repo cache

Signed-off-by: Mike Seese <seesemichaelj@gmail.com>

pkg/downloader/chart_downloader.go

@@ -54,7 +54,7 @@ const (
 )
 
 // ErrNoOwnerRepo indicates that a given chart URL can't be found in any repos.
-var ErrNoOwnerRepo = errors.New("could not find a repo containing the given URL")
+var ErrNoOwnerRepo = errors.New("could not find a repo containing the given URL (try 'helm repo update')")
 
 // ChartDownloader handles downloading a chart.
 //
@@ -380,7 +380,8 @@ func (c *ChartDownloader) scanReposForURL(u string, rf *repo.File) (*repo.Entry,
 		idxFile := filepath.Join(c.RepositoryCache, helmpath.CacheIndexFile(r.Config.Name))
 		i, err := repo.LoadIndexFile(idxFile)
 		if err != nil {
-			return nil, errors.Wrap(err, "no cached repo found. (try 'helm repo update')")
+			// No cache for this repository; let's keep looking rather than erroring
+			continue
 		}
 
 		for _, entry := range i.Entries {

pkg/downloader/chart_downloader_test.go

@@ -28,8 +28,9 @@ import (
 )
 
 const (
-	repoConfig = "testdata/repositories.yaml"
-	repoCache  = "testdata/repository"
+	repoConfig     = "testdata/repositories.yaml"
+	repoCache      = "testdata/repository"
+	repoCacheEmpty = "testdata/repository-empty"
 )
 
 func TestResolveChartRef(t *testing.T) {
@@ -344,3 +345,30 @@ func TestScanReposForURL(t *testing.T) {
 		t.Fatalf("expected ErrNoOwnerRepo, got %v", err)
 	}
 }
+
+// In an scenario where a full URL is provided, chart_downloader will swallow the
+// ErrNoOwnerRepo error and return an HTTP client to download the chart. This specific
+// test shows that the chart will get downloaded in that scenario if the cache is empty
+// (hence `repoCacheEmpty`).
+func TestScanReposForURLWithEmptyCache(t *testing.T) {
+	c := ChartDownloader{
+		Out:              os.Stderr,
+		Verify:           VerifyLater,
+		RepositoryConfig: repoConfig,
+		RepositoryCache:  repoCacheEmpty,
+		Getters: getter.All(&cli.EnvSettings{
+			RepositoryConfig: repoConfig,
+			RepositoryCache:  repoCacheEmpty,
+		}),
+	}
+
+	u := "http://example.com/alpine-0.2.0.tgz"
+	rf, err := repo.LoadFile(repoConfig)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if _, err = c.scanReposForURL(u, rf); err != ErrNoOwnerRepo {
+		t.Fatalf("expected ErrNoOwnerRepo, got %v", err)
+	}
+}