improvements mid may 2025 (#24)

* General improvements and bug fixes. * Improve tests coverage. * fixup! Improve tests coverage. * Update README.md with latest changes. * Fix the uint32 * Resolve issue with race condition for logging. * fixup! Merge remote-tracking branch 'origin/main' into improvements-mid-apr-2025 * Fix the test of the rate limiter * Add default ratelimit.json file * Update dependencies. * Significant refactor. * fixup! Significant refactor. * fixup! Merge remote-tracking branch 'origin/main' into improvements-mid-apr-2025 * fixup! fixup! Merge remote-tracking branch 'origin/main' into improvements-mid-apr-2025 * fixup! fixup! fixup! Merge remote-tracking branch 'origin/main' into improvements-mid-apr-2025 * fixup! fixup! fixup! fixup! fixup! Merge remote-tracking branch 'origin/main' into improvements-mid-apr-2025 * fixup! fixup! fixup! fixup! fixup! fixup! Merge remote-tracking branch 'origin/main' into improvements-mid-apr-2025 * fixup! fixup! fixup! fixup! fixup! fixup! fixup! Merge remote-tracking branch 'origin/main' into improvements-mid-apr-2025 * fixup! fixup! fixup! fixup! fixup! fixup! fixup! fixup! Merge remote-tracking branch 'origin/main' into improvements-mid-apr-2025 * fixup! fixup! fixup! fixup! fixup! fixup! fixup! fixup! fixup! Merge remote-tracking branch 'origin/main' into improvements-mid-apr-2025 * fixup! fixup! fixup! fixup! fixup! fixup! fixup! fixup! fixup! fixup! Merge remote-tracking branch 'origin/main' into improvements-mid-apr-2025
2026-06-05 23:03:48 +00:00 · 2025-09-30 18:27:33 +01:00
parent 3bd96cbd8a
commit cedee416a8
80 changed files with 22799 additions and 647 deletions
@@ -0,0 +1,251 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"time"
+)
+
+// Error codes for structured error responses
+const (
+	ErrCodeConnectionRefused  = "CONNECTION_REFUSED"
+	ErrCodeConnectionReset    = "CONNECTION_RESET"
+	ErrCodeTimeout            = "TIMEOUT"
+	ErrCodeCircuitOpen        = "CIRCUIT_OPEN"
+	ErrCodeRateLimited        = "RATE_LIMITED"
+	ErrCodeInvalidRequest     = "INVALID_REQUEST"
+	ErrCodeBackendError       = "BACKEND_ERROR"
+	ErrCodeInternalError      = "INTERNAL_ERROR"
+	ErrCodeUnauthorized       = "UNAUTHORIZED"
+	ErrCodeForbidden          = "FORBIDDEN"
+	ErrCodeNotFound           = "NOT_FOUND"
+	ErrCodeServiceUnavailable = "SERVICE_UNAVAILABLE"
+	ErrCodeBadGateway         = "BAD_GATEWAY"
+	ErrCodeInvalidResponse    = "INVALID_RESPONSE"
+	ErrCodeQueryTooComplex    = "QUERY_TOO_COMPLEX"
+	ErrCodeCacheFailed        = "CACHE_FAILED"
+	ErrCodeContextCanceled    = "CONTEXT_CANCELED"
+)
+
+// ProxyError represents a structured error response
+type ProxyError struct {
+	Code       string                 `json:"code"`               // Machine-readable error code
+	Message    string                 `json:"message"`            // Human-readable error message
+	Details    string                 `json:"details,omitempty"`  // Additional error details
+	Retryable  bool                   `json:"retryable"`          // Whether the request can be retried
+	StatusCode int                    `json:"status_code"`        // HTTP status code
+	Timestamp  time.Time              `json:"timestamp"`          // When the error occurred
+	TraceID    string                 `json:"trace_id,omitempty"` // Trace ID for correlation
+	Metadata   map[string]interface{} `json:"metadata,omitempty"` // Additional context
+	Cause      error                  `json:"-"`                  // Original error (not serialized)
+}
+
+// Error implements the error interface
+func (e *ProxyError) Error() string {
+	if e.Details != "" {
+		return fmt.Sprintf("%s: %s (%s)", e.Code, e.Message, e.Details)
+	}
+	return fmt.Sprintf("%s: %s", e.Code, e.Message)
+}
+
+// Unwrap returns the underlying error
+func (e *ProxyError) Unwrap() error {
+	return e.Cause
+}
+
+// MarshalJSON implements custom JSON marshaling
+func (e *ProxyError) MarshalJSON() ([]byte, error) {
+	type Alias ProxyError
+	return json.Marshal(&struct {
+		*Alias
+		CauseMessage string `json:"cause,omitempty"`
+	}{
+		Alias: (*Alias)(e),
+		CauseMessage: func() string {
+			if e.Cause != nil {
+				return e.Cause.Error()
+			}
+			return ""
+		}(),
+	})
+}
+
+// NewProxyError creates a new structured error
+func NewProxyError(code, message string, statusCode int, retryable bool) *ProxyError {
+	return &ProxyError{
+		Code:       code,
+		Message:    message,
+		StatusCode: statusCode,
+		Retryable:  retryable,
+		Timestamp:  time.Now(),
+		Metadata:   make(map[string]interface{}),
+	}
+}
+
+// WithDetails adds details to the error
+func (e *ProxyError) WithDetails(details string) *ProxyError {
+	e.Details = details
+	return e
+}
+
+// WithCause adds the underlying cause
+func (e *ProxyError) WithCause(cause error) *ProxyError {
+	e.Cause = cause
+	return e
+}
+
+// WithTraceID adds a trace ID
+func (e *ProxyError) WithTraceID(traceID string) *ProxyError {
+	e.TraceID = traceID
+	return e
+}
+
+// WithMetadata adds metadata
+func (e *ProxyError) WithMetadata(key string, value interface{}) *ProxyError {
+	e.Metadata[key] = value
+	return e
+}
+
+// Common error constructors
+
+// NewConnectionError creates a connection-related error
+func NewConnectionError(err error) *ProxyError {
+	code := ErrCodeConnectionRefused
+	if err != nil {
+		errStr := err.Error()
+		if contains(errStr, "reset") {
+			code = ErrCodeConnectionReset
+		}
+	}
+
+	return NewProxyError(code, "Failed to connect to backend", 502, true).
+		WithCause(err)
+}
+
+// NewTimeoutError creates a timeout error
+func NewTimeoutError(err error) *ProxyError {
+	return NewProxyError(ErrCodeTimeout, "Request timed out", 504, false).
+		WithCause(err)
+}
+
+// NewCircuitOpenError creates a circuit breaker open error
+func NewCircuitOpenError() *ProxyError {
+	return NewProxyError(ErrCodeCircuitOpen, "Service temporarily unavailable due to circuit breaker", 503, false).
+		WithDetails("The backend service is currently experiencing issues. Please try again later.")
+}
+
+// NewRateLimitError creates a rate limit error
+func NewRateLimitError(userID, role string) *ProxyError {
+	return NewProxyError(ErrCodeRateLimited, "Rate limit exceeded", 429, false).
+		WithDetails("You have exceeded the rate limit for your role").
+		WithMetadata("user_id", userID).
+		WithMetadata("role", role)
+}
+
+// NewBackendError creates a backend error from status code
+func NewBackendError(statusCode int, body string) *ProxyError {
+	code := ErrCodeBackendError
+	message := "Backend returned an error"
+	retryable := false
+
+	switch {
+	case statusCode == 429:
+		code = ErrCodeRateLimited
+		message = "Backend rate limit exceeded"
+		retryable = true
+	case statusCode == 503:
+		code = ErrCodeServiceUnavailable
+		message = "Backend service unavailable"
+		retryable = true
+	case statusCode == 502 || statusCode == 504:
+		code = ErrCodeBadGateway
+		message = "Bad gateway"
+		retryable = true
+	case statusCode >= 500:
+		code = ErrCodeBackendError
+		message = "Backend server error"
+		retryable = true
+	case statusCode == 404:
+		code = ErrCodeNotFound
+		message = "Resource not found"
+	case statusCode == 403:
+		code = ErrCodeForbidden
+		message = "Access forbidden"
+	case statusCode == 401:
+		code = ErrCodeUnauthorized
+		message = "Unauthorized"
+	case statusCode >= 400:
+		code = ErrCodeInvalidRequest
+		message = "Invalid request"
+	}
+
+	return NewProxyError(code, message, statusCode, retryable).
+		WithMetadata("backend_status", statusCode).
+		WithMetadata("backend_body", truncateString(body, 500))
+}
+
+// NewInvalidResponseError creates an invalid response error
+func NewInvalidResponseError(details string) *ProxyError {
+	return NewProxyError(ErrCodeInvalidResponse, "Backend returned invalid response", 502, false).
+		WithDetails(details)
+}
+
+// NewInternalError creates an internal error
+func NewInternalError(err error) *ProxyError {
+	return NewProxyError(ErrCodeInternalError, "Internal proxy error", 500, false).
+		WithCause(err)
+}
+
+// NewContextCanceledError creates a context canceled error
+func NewContextCanceledError() *ProxyError {
+	return NewProxyError(ErrCodeContextCanceled, "Request canceled", 499, false).
+		WithDetails("The request was canceled by the client")
+}
+
+// Helper functions
+
+func contains(s, substr string) bool {
+	return len(s) > 0 && len(substr) > 0 && len(s) >= len(substr) && (s == substr || len(s) > len(substr) && (s[:len(substr)] == substr || s[len(s)-len(substr):] == substr || containsMiddle(s, substr)))
+}
+
+func containsMiddle(s, substr string) bool {
+	for i := 0; i <= len(s)-len(substr); i++ {
+		if s[i:i+len(substr)] == substr {
+			return true
+		}
+	}
+	return false
+}
+
+func truncateString(s string, maxLen int) string {
+	if len(s) <= maxLen {
+		return s
+	}
+	return s[:maxLen] + "..."
+}
+
+// IsRetryable checks if an error is retryable
+func IsRetryable(err error) bool {
+	if err == nil {
+		return false
+	}
+
+	if proxyErr, ok := err.(*ProxyError); ok {
+		return proxyErr.Retryable
+	}
+
+	return false
+}
+
+// GetStatusCode extracts the status code from an error
+func GetStatusCode(err error) int {
+	if err == nil {
+		return 200
+	}
+
+	if proxyErr, ok := err.(*ProxyError); ok {
+		return proxyErr.StatusCode
+	}
+
+	return 500
+}