Review file permission for otel collector config (#1037)

* Review file permission for otel collector config

* Merge v3, removed error from parameters

Author: john-david3

internal/collector/settings.go

@@ -73,6 +73,22 @@ func createURIs(cfg *config.Config) []string {
 	return []string{cfg.Collector.ConfigPath}
 }
 
+func createFile(confPath string) error {
+	// Create if doesn't exist.
+	_, createErr := os.Create(confPath)
+	if createErr != nil {
+		return createErr
+	}
+
+	// Set the file permissions to 600.
+	permissionErr := os.Chmod(confPath, configFilePermission)
+	if permissionErr != nil {
+		return permissionErr
+	}
+
+	return nil
+}
+
 // Generates a OTel Collector config to a file by injecting the Metrics Config to a Go template.
 func writeCollectorConfig(conf *config.Collector) error {
 	otelcolTemplate, err := template.New(otelTemplatePath).Parse(otelcolTemplate)
@@ -82,17 +98,16 @@ func writeCollectorConfig(conf *config.Collector) error {
 
 	confPath := filepath.Clean(conf.ConfigPath)
 
-	// Check if file exists.
+	// Check if file exists, if not create it.
 	_, err = os.Stat(confPath)
 	if err != nil {
 		if !os.IsNotExist(err) {
 			return err
 		}
 
-		// Create if doesn't exist.
-		_, createErr := os.Create(confPath)
-		if createErr != nil {
-			return createErr
+		fileErr := createFile(confPath)
+		if fileErr != nil {
+			return fileErr
 		}
 	}
 

internal/collector/settings_test.go

@@ -171,3 +171,19 @@ func TestTemplateWrite(t *testing.T) {
 	// Convert to string for human readable error messages.
 	assert.Equal(t, string(expected), string(actual))
 }
+
+func TestFilePermissions(t *testing.T) {
+	tmpDir := t.TempDir()
+
+	cfg := types.AgentConfig()
+	actualConfPath := filepath.Join(tmpDir, "nginx-agent-otelcol-test.yaml")
+	cfg.Collector.ConfigPath = actualConfPath
+
+	err := writeCollectorConfig(cfg.Collector)
+	require.NoError(t, err)
+
+	// Check file permissions are 600
+	fileInfo, err := os.Stat(actualConfPath)
+	require.NoError(t, err)
+	assert.Equal(t, os.FileMode(0o600), fileInfo.Mode())
+}