Add server mode tests to dtailhealth integration tests

- Update TestDTailHealth1 and TestDTailHealth2 to run in both serverless and server modes
- TestDTailHealth1 tests without --server flag (warning state expected)
- TestDTailHealth2 tests unreachable server (critical state expected)
- TestDTailHealthCheck3 restructured to follow same pattern (server mode only)
- All dtailhealth tests now pass in appropriate modes
- Added time import for server startup delay

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

1 files changed, 125 insertions, 0 deletions

diff --git a/integrationtests/dtailhealth_test.go b/integrationtests/dtailhealth_test.go
index 7946824..fc0a693 100644
--- a/integrationtests/dtailhealth_test.go
+++ b/integrationtests/dtailhealth_test.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 	"testing"
+	"time"
 
 	"github.com/mimecast/dtail/internal/config"
 )
@@ -14,6 +15,20 @@ func TestDTailHealth1(t *testing.T) {
 		t.Log("Skipping")
 		return
 	}
+
+	// Test in serverless mode
+	t.Run("Serverless", func(t *testing.T) {
+		testDTailHealth1Serverless(t)
+	})
+
+	// Test in server mode - this test checks when no servers are specified
+	// so server mode behavior should be the same
+	t.Run("ServerMode", func(t *testing.T) {
+		testDTailHealth1WithServer(t)
+	})
+}
+
+func testDTailHealth1Serverless(t *testing.T) {
 	outFile := "dtailhealth1.stdout.tmp"
 	expectedOutFile := "dtailhealth1.expected"
 
@@ -31,11 +46,67 @@ func TestDTailHealth1(t *testing.T) {
 	os.Remove(outFile)
 }
 
+func testDTailHealth1WithServer(t *testing.T) {
+	outFile := "dtailhealth1.stdout.tmp"
+	expectedOutFile := "dtailhealth1.expected"
+	port := getUniquePortNumber()
+	bindAddress := "localhost"
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	// Start dserver
+	_, _, _, err := startCommand(ctx, t,
+		"", "../dserver",
+		"--cfg", "none",
+		"--logger", "stdout",
+		"--logLevel", "error",
+		"--bindAddress", bindAddress,
+		"--port", fmt.Sprintf("%d", port),
+	)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
+	// Give server time to start
+	time.Sleep(500 * time.Millisecond)
+
+	t.Log("Server mode check without --server flag, is supposed to exit with warning state.")
+	// Run dtailhealth without specifying --server flag
+	exitCode, err := runCommand(ctx, t, outFile, "../dtailhealth")
+	if exitCode != 1 {
+		t.Errorf("Expected exit code '1' but got '%d': %v", exitCode, err)
+		return
+	}
+
+	cancel()
+
+	if err := compareFiles(t, outFile, expectedOutFile); err != nil {
+		t.Error(err)
+		return
+	}
+	os.Remove(outFile)
+}
+
 func TestDTailHealth2(t *testing.T) {
 	if !config.Env("DTAIL_INTEGRATION_TEST_RUN_MODE") {
 		t.Log("Skipping")
 		return
 	}
+
+	// Test in serverless mode
+	t.Run("Serverless", func(t *testing.T) {
+		testDTailHealth2Serverless(t)
+	})
+
+	// Test in server mode - testing unreachable server
+	t.Run("ServerMode", func(t *testing.T) {
+		testDTailHealth2WithServer(t)
+	})
+}
+
+func testDTailHealth2Serverless(t *testing.T) {
 	outFile := "dtailhealth2.stdout.tmp"
 	expectedOutFile := "dtailhealth2.expected"
 
@@ -56,11 +127,65 @@ func TestDTailHealth2(t *testing.T) {
 	os.Remove(outFile)
 }
 
+func testDTailHealth2WithServer(t *testing.T) {
+	outFile := "dtailhealth2.stdout.tmp"
+	expectedOutFile := "dtailhealth2.expected"
+	port := getUniquePortNumber()
+	bindAddress := "localhost"
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	// Start dserver  
+	_, _, _, err := startCommand(ctx, t,
+		"", "../dserver",
+		"--cfg", "none",
+		"--logger", "stdout",
+		"--logLevel", "error",
+		"--bindAddress", bindAddress,
+		"--port", fmt.Sprintf("%d", port),
+	)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
+	// Give server time to start
+	time.Sleep(500 * time.Millisecond)
+
+	t.Log("Server mode negative test, checking unreachable server, is supposed to exit with a critical state.")
+	// Check an unreachable server (not the one we started)
+	exitCode, err := runCommand(ctx, t, outFile,
+		"../dtailhealth", "--server", "example:1")
+
+	if exitCode != 2 {
+		t.Error(fmt.Sprintf("Expected exit code '2' but got '%d': %v", exitCode, err))
+		return
+	}
+
+	cancel()
+
+	if err := compareFiles(t, outFile, expectedOutFile); err != nil {
+		t.Error(err)
+		return
+	}
+
+	os.Remove(outFile)
+}
+
 func TestDTailHealthCheck3(t *testing.T) {
 	if !config.Env("DTAIL_INTEGRATION_TEST_RUN_MODE") {
 		t.Log("Skipping")
 		return
 	}
+
+	// This test only makes sense with a server
+	t.Run("ServerMode", func(t *testing.T) {
+		testDTailHealthCheck3WithServer(t)
+	})
+}
+
+func testDTailHealthCheck3WithServer(t *testing.T) {
 	outFile := "dtailhealth3.stdout.tmp"
 	port := getUniquePortNumber()
 	bindAddress := "localhost"