Initial commit: Luminary AI Gateway

OpenAI-compatible AI gateway with Vue admin UI, multi-provider egress,
ingress key governance, monitoring, and security controls.

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/gateway/logbody.go

@@ -0,0 +1,90 @@
+package gateway
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+
+	"github.com/rose_cat707/luminary/internal/provider"
+)
+
+const maxLogBodyBytes = 16384
+
+func truncateLogBody(b []byte) string {
+	if len(b) == 0 {
+		return ""
+	}
+	if len(b) <= maxLogBodyBytes {
+		return string(b)
+	}
+	return string(b[:maxLogBodyBytes]) + "\n...(truncated)"
+}
+
+func extractModelName(body []byte) string {
+	if len(body) == 0 {
+		return ""
+	}
+	var payload struct {
+		Model string `json:"model"`
+	}
+	if err := json.Unmarshal(body, &payload); err != nil {
+		return ""
+	}
+	return payload.Model
+}
+
+func describeForwardError(err error, resp *provider.ChatResponse) string {
+	if err != nil {
+		return err.Error()
+	}
+	if resp == nil {
+		return "unknown error"
+	}
+	if resp.StatusCode < 400 {
+		return ""
+	}
+	if msg := extractAPIErrorMessage(resp.Body); msg != "" {
+		return fmt.Sprintf("status %d: %s", resp.StatusCode, msg)
+	}
+	if len(resp.Body) > 0 {
+		return fmt.Sprintf("status %d: %s", resp.StatusCode, truncateLogBody(resp.Body))
+	}
+	return fmt.Sprintf("status %d", resp.StatusCode)
+}
+
+func extractAPIErrorMessage(body []byte) string {
+	if len(body) == 0 {
+		return ""
+	}
+	var openAI struct {
+		Error struct {
+			Message string `json:"message"`
+			Type    string `json:"type"`
+		} `json:"error"`
+	}
+	if err := json.Unmarshal(body, &openAI); err == nil {
+		if openAI.Error.Message != "" {
+			if openAI.Error.Type != "" {
+				return openAI.Error.Type + ": " + openAI.Error.Message
+			}
+			return openAI.Error.Message
+		}
+	}
+	var simple struct {
+		Message string `json:"message"`
+		Error   string `json:"error"`
+	}
+	if err := json.Unmarshal(body, &simple); err == nil {
+		if simple.Message != "" {
+			return simple.Message
+		}
+		if simple.Error != "" {
+			return simple.Error
+		}
+	}
+	s := strings.TrimSpace(string(body))
+	if len(s) > 240 {
+		return s[:240] + "..."
+	}
+	return s
+}