Add cache-path to repo_add, added extra test in repo_update_test to assert correct cache path usage

Signed-off-by: Trond Hindenes <trond@hindenes.com>

cmd/helm/repo_add.go

@@ -129,7 +129,7 @@ func (o *repoAddOptions) run(out io.Writer) error {
 	if err != nil {
 		return err
 	}
-
+	r.CachePath = settings.RepositoryCache
 	if _, err := r.DownloadIndexFile(); err != nil {
 		return errors.Wrapf(err, "looks like %q is not a valid chart repository or cannot be reached", o.url)
 	}

cmd/helm/repo_update_test.go

@@ -18,14 +18,15 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"io"
-	"strings"
-	"testing"
-
 	"helm.sh/helm/v3/internal/test/ensure"
 	"helm.sh/helm/v3/pkg/getter"
 	"helm.sh/helm/v3/pkg/repo"
 	"helm.sh/helm/v3/pkg/repo/repotest"
+	"io"
+	"io/ioutil"
+	"path/filepath"
+	"strings"
+	"testing"
 )
 
 func TestUpdateCmd(t *testing.T) {
@@ -79,3 +80,34 @@ func TestUpdateCharts(t *testing.T) {
 		t.Error("Update was not successful")
 	}
 }
+
+func TestUpdateChartsCustomCache(t *testing.T) {
+	defer resetEnv()()
+	defer ensure.HelmHome(t)()
+
+	ts, err := repotest.NewTempServer("testdata/testserver/*.*")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer ts.Stop()
+
+	r, err := repo.NewChartRepository(&repo.Entry{
+		Name: "charts",
+		URL:  ts.URL(),
+	}, getter.All(settings))
+	if err != nil {
+		t.Error(err)
+	}
+
+	cachePath := ensure.TempDir(t)
+	cacheFile := filepath.Join(cachePath, "charts-index.yaml")
+	r.CachePath = cachePath
+
+	b := bytes.NewBuffer(nil)
+	updateCharts([]*repo.ChartRepository{r}, b)
+
+	_, err = ioutil.ReadFile(cacheFile)
+	if err != nil {
+		t.Error(err)
+	}
+}