plugin/nomad: Add a Nomad plugin (#7467)

Signed-off-by: Olli Janatuinen <olli.janatuinen@gmail.com>

plugin/nomad/setup_test.go

@@ -0,0 +1,110 @@
+package nomad
+
+import (
+	"testing"
+
+	"github.com/coredns/caddy"
+
+	nomad "github.com/hashicorp/nomad/api"
+)
+
+func TestSetupNomad(t *testing.T) {
+	tests := []struct {
+		name        string
+		config      string
+		shouldErr   bool
+		expectedTTL uint32
+	}{
+		{
+			name: "valid_config_default_ttl",
+			config: `
+nomad service.nomad {
+    address http://127.0.0.1:4646
+    token test-token
+}`,
+			shouldErr:   false,
+			expectedTTL: uint32(defaultTTL),
+		},
+		{
+			name: "valid_config_custom_ttl",
+			config: `
+nomad service.nomad {
+    address http://127.0.0.1:4646
+    token test-token
+    ttl 60
+}`,
+			shouldErr:   false,
+			expectedTTL: 60,
+		},
+		{
+			name: "invalid_ttl_negative",
+			config: `
+nomad service.nomad {
+    address http://127.0.0.1:4646
+    token test-token
+    ttl -1
+}`,
+			shouldErr: true,
+		},
+		{
+			name: "invalid_ttl_too_large",
+			config: `
+nomad service.nomad {
+    address http://127.0.0.1:4646
+    token test-token
+    ttl 3601
+}`,
+			shouldErr: true,
+		},
+		{
+			name: "invalid_property",
+			config: `
+nomad service.nomad {
+    address http://127.0.0.1:4646
+    token test-token
+    invalid_property
+}`,
+			shouldErr: true,
+		},
+		{
+			name: "multiple_addresses",
+			config: `
+nomad service.nomad {
+    address http://127.0.0.1:4646 http://127.0.0.2:4646
+    token test-token
+}`,
+			shouldErr:   false,
+			expectedTTL: uint32(defaultTTL),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			c := caddy.NewTestController("dns", tt.config)
+			n := &Nomad{
+				ttl:     uint32(defaultTTL),
+				clients: make([]*nomad.Client, 0),
+				current: -1,
+			}
+
+			err := parse(c, n)
+			if tt.shouldErr && err == nil {
+				t.Fatalf("Test %s: expected error but got none", tt.name)
+			}
+			if !tt.shouldErr && err != nil {
+				t.Fatalf("Test %s: expected no error but got: %v", tt.name, err)
+			}
+			if tt.shouldErr {
+				return
+			}
+
+			if n.ttl != tt.expectedTTL {
+				t.Errorf("Test %s: expected TTL %d, got %d", tt.name, tt.expectedTTL, n.ttl)
+			}
+
+			if len(n.clients) == 0 {
+				t.Errorf("Test %s: expected at least one client to be created", tt.name)
+			}
+		})
+	}
+}