added more tests

pkg/envoy/proxy.go

@@ -286,9 +286,10 @@ func (p *Proxy) buildCommand(ctx context.Context, cfgPath string) *exec.Cmd {
 // removeArgAndGetValue Function to get new args after removing given key
 // and also returns the value of key
 func removeArgAndGetValue(stringAr []string, key string) ([]string, string) {
-	for index, value := range stringAr {
-		if value == key {
-			return append(stringAr[:index], stringAr[index+2:]...), stringAr[index+1]
+	for index, item := range stringAr {
+		if item == key {
+			valueToReturn := stringAr[index+1]
+			return append(stringAr[:index], stringAr[index+2:]...), valueToReturn
 		}
 	}
 	return stringAr, ""

pkg/envoy/proxy_test.go

@@ -209,3 +209,66 @@ func TestProxy_OverridingLoggerAndExtraArgs(t *testing.T) {
 		return p.cmd.Process.Signal(syscall.Signal(0)) == os.ErrProcessDone
 	}, 2*time.Second, 50*time.Millisecond)
 }
+
+func TestProxy_EnvoyExtraArgs(t *testing.T) {
+	bootstrapConfig := []byte(`hello world`)
+
+	// Test checks we are starting proxy with only one argument of log-level
+	// When log-level is present in both ProxyConfig and ExtraArgs
+	// We override the log-level with that of ExtraArgs
+	outputPath := testOutputPath()
+	t.Cleanup(func() { _ = os.Remove(outputPath) })
+
+	p, err := NewProxy(ProxyConfig{
+		Logger:            hclog.New(&hclog.LoggerOptions{Level: hclog.Warn, Output: io.Discard}),
+		EnvoyErrorStream:  io.Discard,
+		EnvoyOutputStream: io.Discard,
+		ExecutablePath:    "testdata/fake-envoy",
+		ExtraArgs:         []string{"--test-output", outputPath, "--log-level", "debug", "--concurrency", "1"},
+		BootstrapConfig:   bootstrapConfig,
+	})
+	require.NoError(t, err)
+	require.NoError(t, p.Run(context.Background()))
+	t.Cleanup(func() { _ = p.Stop() })
+
+	// Read the output written by fake-envoy. It might take a while, so poll the
+	// file for a couple of second
+	var output struct {
+		Args       []byte
+		ConfigData []byte
+	}
+	require.Eventually(t, func() bool {
+		outputBytes, err := os.ReadFile(outputPath)
+		if err != nil {
+			t.Logf("failed to read output file: %v", err)
+			return false
+		}
+		if err := json.Unmarshal(outputBytes, &output); err != nil {
+			t.Logf("failed to unmarshal output file: %v", err)
+			return false
+		}
+		return true
+	}, 2*time.Second, 50*time.Millisecond)
+
+	// Check that fake-envoy was able to read the config from the pipe.
+	require.Equal(t, bootstrapConfig, output.ConfigData)
+
+	// Check that we're correctly configuring the log level.
+	require.Contains(t, string(output.Args), "--log-level debug")
+
+	// Check that we're removing the logger in Proxy config and overriding it with extra args
+	require.NotContains(t, string(output.Args), "--log-level warn")
+
+	// Check that we're disabling hot restarts.
+	require.Contains(t, string(output.Args), "--disable-hot-restart")
+
+	// Check the process is still running.
+	require.NoError(t, p.cmd.Process.Signal(syscall.Signal(0)))
+
+	// Ensure Stop kills and reaps the process.
+	require.NoError(t, p.Stop())
+
+	require.Eventually(t, func() bool {
+		return p.cmd.Process.Signal(syscall.Signal(0)) == os.ErrProcessDone
+	}, 2*time.Second, 50*time.Millisecond)
+}