cli/cmd: add tests for getKubeconfig

To make sure we do it right, as otherwise it might be destructive.

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

cli/cmd/utils_internal_test.go

@@ -0,0 +1,205 @@
+// Copyright 2020 The Lokomotive Authors
+//
+// 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 cmd
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/spf13/viper"
+)
+
+type kubeconfigSources struct {
+	flag       string
+	env        string
+	configFile string
+}
+
+func prepareKubeconfigSource(t *testing.T, k *kubeconfigSources) {
+	// Ensure viper flag is NOT empty.
+	viper.Set(kubeconfigFlag, k.flag)
+
+	if k.env == "" {
+		// Ensure KUBECONFIG is not set.
+		if err := os.Unsetenv(kubeconfigEnvVariable); err != nil {
+			t.Fatalf("unsetting %q environment variable: %v", kubeconfigEnvVariable, err)
+		}
+	}
+
+	if k.env != "" {
+		// Ensure KUBECONFIG IS set.
+		if err := os.Setenv(kubeconfigEnvVariable, k.env); err != nil {
+			t.Fatalf("setting %q environment variable: %v", kubeconfigEnvVariable, err)
+		}
+	}
+
+	// Ensure there is no lokocfg configuration in working directory.
+	tmpDir, err := ioutil.TempDir("", "lokoctl-tests-")
+	if err != nil {
+		t.Fatalf("creating tmp dir: %v", err)
+	}
+
+	t.Cleanup(func() {
+		if err := os.RemoveAll(tmpDir); err != nil {
+			t.Logf("removing temp dir %q: %v", tmpDir, err)
+		}
+	})
+
+	if err := os.Chdir(tmpDir); err != nil {
+		t.Fatalf("changing working directory to %q: %v", tmpDir, err)
+	}
+
+	if k.configFile != "" {
+		path := filepath.Join(tmpDir, "cluster.lokocfg")
+		if err := ioutil.WriteFile(path, []byte(k.configFile), 0600); err != nil {
+			t.Fatalf("writing file %q: %v", path, err)
+		}
+	}
+}
+
+func TestGetKubeconfigFlag(t *testing.T) {
+	expectedPath := "/foo"
+
+	k := &kubeconfigSources{
+		configFile: `cluster "packet" {
+  asset_dir = "/bad"
+
+  cluster_name      = ""
+  controller_count  = 0
+  facility          = ""
+  management_cidrs  = []
+  node_private_cidr = ""
+  project_id        = ""
+  ssh_pubkeys       = []
+  dns {
+    provider = ""
+    zone     = ""
+  }
+  worker_pool "foo" {
+    count = 0
+  }
+}`,
+		flag: expectedPath,
+		env:  "/badpath",
+	}
+
+	prepareKubeconfigSource(t, k)
+
+	kubeconfig, err := getKubeconfig()
+	if err != nil {
+		t.Fatalf("getting kubeconfig: %v", err)
+	}
+
+	if kubeconfig != expectedPath {
+		t.Fatalf("expected %q, got %q", expectedPath, kubeconfig)
+	}
+}
+
+func TestGetKubeconfigConfigFile(t *testing.T) {
+	expectedPath := assetsKubeconfig("/foo")
+
+	k := &kubeconfigSources{
+		configFile: `cluster "packet" {
+  asset_dir = "/foo"
+
+  cluster_name      = ""
+  controller_count  = 0
+  facility          = ""
+  management_cidrs  = []
+  node_private_cidr = ""
+  project_id        = ""
+  ssh_pubkeys       = []
+  dns {
+    provider = ""
+    zone     = ""
+  }
+  worker_pool "foo" {
+    count = 0
+  }
+}`,
+
+		env: "/badpath",
+	}
+
+	prepareKubeconfigSource(t, k)
+
+	kubeconfig, err := getKubeconfig()
+	if err != nil {
+		t.Fatalf("getting kubeconfig: %v", err)
+	}
+
+	if kubeconfig != expectedPath {
+		t.Fatalf("expected %q, got %q", expectedPath, kubeconfig)
+	}
+}
+
+func TestGetKubeconfigBadConfigFile(t *testing.T) {
+	expectedPath := ""
+
+	k := &kubeconfigSources{
+		configFile: `cluster "packet" {
+	asset_dir = "/foo"
+}`,
+	}
+
+	prepareKubeconfigSource(t, k)
+
+	kubeconfig, err := getKubeconfig()
+	if err == nil {
+		t.Errorf("getting kubeconfig with bad configuration should fail")
+	}
+
+	if kubeconfig != expectedPath {
+		t.Fatalf("if getting kubeconfig fails, empty path should be returned")
+	}
+}
+
+func TestGetKubeconfigEnvVariable(t *testing.T) {
+	expectedPath := "/foo"
+
+	k := &kubeconfigSources{
+		env: expectedPath,
+	}
+
+	prepareKubeconfigSource(t, k)
+
+	kubeconfig, err := getKubeconfig()
+	if err != nil {
+		t.Fatalf("getting kubeconfig: %v", err)
+	}
+
+	if kubeconfig != expectedPath {
+		t.Fatalf("expected %q, got %q", expectedPath, kubeconfig)
+	}
+}
+
+func TestGetKubeconfigDefault(t *testing.T) {
+	expectedPath := expandKubeconfigPath(defaultKubeconfigPath)
+
+	k := &kubeconfigSources{}
+
+	prepareKubeconfigSource(t, k)
+
+	kubeconfig, err := getKubeconfig()
+	if err != nil {
+		t.Fatalf("getting kubeconfig: %v", err)
+	}
+
+	if kubeconfig != expectedPath {
+		t.Fatalf("expected %q, got %q", expectedPath, kubeconfig)
+	}
+}