join: make Azure instance names k8s compliant (#807)

join: make Azure instance names k8s compliant

joinservice/internal/kubernetes/kubernetes_test.go

@@ -0,0 +1,63 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+package kubernetes
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"go.uber.org/goleak"
+)
+
+func TestMain(m *testing.M) {
+	goleak.VerifyTestMain(m)
+}
+
+func TestK8sCompliantHostname(t *testing.T) {
+	testCases := map[string]struct {
+		input    string
+		expected string
+		wantErr  bool
+	}{
+		"no change": {
+			input:    "test",
+			expected: "test",
+		},
+		"uppercase": {
+			input:    "TEST",
+			expected: "test",
+		},
+		"underscore": {
+			input:    "test_node",
+			expected: "test-node",
+		},
+		"empty": {
+			input:    "",
+			expected: "",
+			wantErr:  true,
+		},
+		"error": {
+			input:    "test_node_",
+			expected: "",
+			wantErr:  true,
+		},
+	}
+
+	for name, tc := range testCases {
+		t.Run(name, func(t *testing.T) {
+			assert := assert.New(t)
+
+			actual, err := k8sCompliantHostname(tc.input)
+			if tc.wantErr {
+				assert.Error(err)
+				return
+			}
+			assert.NoError(err)
+			assert.Equal(tc.expected, actual)
+		})
+	}
+}