pkg/components/util: make HelmActionConfig use kubeconfig file content

As part of #608, this commit changes the implementation of
HelmActionConfig function to read the content of given kubeconfig file
and then use the content to construct Helm's actionConfig. This will
make easier changing the function signature to accept content of
kubeconfig file in the future changes.

Signed-off-by: Mateusz Gozdek <mateusz@kinvolk.io>

pkg/components/util/install.go

@@ -16,12 +16,13 @@ package util
 
 import (
 	"fmt"
+	"io/ioutil"
 
 	"helm.sh/helm/v3/pkg/action"
-	"helm.sh/helm/v3/pkg/kube"
 	"helm.sh/helm/v3/pkg/storage/driver"
 
 	"github.com/kinvolk/lokomotive/pkg/components"
+	"github.com/kinvolk/lokomotive/pkg/k8sutil"
 )
 
 // InstallComponent installs given component using given kubeconfig.
@@ -99,11 +100,20 @@ func InstallAsRelease(name string, c components.Component, kubeconfig string) er
 func HelmActionConfig(ns string, kubeconfig string) (*action.Configuration, error) {
 	actionConfig := &action.Configuration{}
 
+	kubeconfigContent, err := ioutil.ReadFile(kubeconfig) // #nosec G304
+	if err != nil {
+		return nil, fmt.Errorf("failed to read kubeconfig file %q: %v", kubeconfig, err)
+	}
+
+	getter, err := k8sutil.NewGetter(kubeconfigContent)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create Kubernetes client getter: %v", err)
+	}
+
 	// TODO: Add some logging implementation? We currently just pass an empty function for logging.
-	kubeConfig := kube.GetConfig(kubeconfig, "", ns)
 	logF := func(format string, v ...interface{}) {}
 
-	if err := actionConfig.Init(kubeConfig, ns, "secret", logF); err != nil {
+	if err := actionConfig.Init(getter, ns, "secret", logF); err != nil {
 		return nil, fmt.Errorf("failed initializing helm: %w", err)
 	}
 

pkg/components/util/install_test.go

@@ -0,0 +1,80 @@
+package util_test
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/kinvolk/lokomotive/pkg/components/util"
+)
+
+const (
+	validKubeconfig = `
+apiVersion: v1
+kind: Config
+clusters:
+- name: admin
+  cluster:
+    server: https://nonexistent:6443
+users:
+- name: admin
+  user:
+    token: "foo.bar"
+current-context: admin
+contexts:
+- name: admin
+  context:
+    cluster: admin
+    user: admin
+`
+)
+
+func TestHelmActionConfigFromValidKubeconfigFile(t *testing.T) {
+	tmpFile, err := ioutil.TempFile("", "lokoctl-tests-")
+	if err != nil {
+		t.Fatalf("creating tmp file should succeed, got: %v", err)
+	}
+
+	defer func() {
+		if err := os.Remove(tmpFile.Name()); err != nil {
+			t.Logf("failed to remove tmp file %q: %v", tmpFile.Name(), err)
+		}
+	}()
+
+	if _, err := tmpFile.Write([]byte(validKubeconfig)); err != nil {
+		t.Fatalf("writing to tmp file %q should succeed, got: %v", tmpFile.Name(), err)
+	}
+
+	if err := tmpFile.Close(); err != nil {
+		t.Fatalf("closing tmp file %q should succeed, got: %v", tmpFile.Name(), err)
+	}
+
+	if _, err := util.HelmActionConfig("foo", tmpFile.Name()); err != nil {
+		t.Fatalf("creating helm action config from valid kubeconfig file should succeed, got: %v", err)
+	}
+}
+
+func TestHelmActionConfigFromInvalidKubeconfigFile(t *testing.T) {
+	tmpFile, err := ioutil.TempFile("", "lokoctl-tests-")
+	if err != nil {
+		t.Fatalf("creating tmp file should succeed, got: %v", err)
+	}
+
+	defer func() {
+		if err := os.Remove(tmpFile.Name()); err != nil {
+			t.Logf("failed to remove tmp file %q: %v", tmpFile.Name(), err)
+		}
+	}()
+
+	if _, err := tmpFile.Write([]byte("foo")); err != nil {
+		t.Fatalf("writing to tmp file %q should succeed, got: %v", tmpFile.Name(), err)
+	}
+
+	if err := tmpFile.Close(); err != nil {
+		t.Fatalf("closing tmp file %q should succeed, got: %v", tmpFile.Name(), err)
+	}
+
+	if _, err := util.HelmActionConfig("foo", tmpFile.Name()); err == nil {
+		t.Fatalf("creating helm action config from invalid kubeconfig file should fail")
+	}
+}