added lokiwriter log, server logger setting function and some zerolog logs

lokiwriter.go

@@ -0,0 +1,84 @@
+package meowlib
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+)
+
+type LokiWriter struct {
+	url        string
+	labels     map[string]string
+	httpClient *http.Client
+}
+
+type LokiPayload struct {
+	Streams []LokiStream `json:"streams"`
+}
+
+type LokiStream struct {
+	Labels  string      `json:"labels"`
+	Entries []LokiEntry `json:"entries"`
+}
+
+type LokiEntry struct {
+	Timestamp string `json:"ts"`
+	Line      string `json:"line"`
+}
+
+func NewLokiWriter(url string, labels map[string]string) *LokiWriter {
+	return &LokiWriter{
+		url:        url,
+		labels:     labels,
+		httpClient: &http.Client{},
+	}
+}
+
+func (w *LokiWriter) Write(p []byte) (n int, err error) {
+	// Format log entry for Loki
+	entry := LokiEntry{
+		Timestamp: time.Now().Format(time.RFC3339Nano),
+		Line:      string(p),
+	}
+
+	labels := []string{}
+	for k, v := range w.labels {
+		labels = append(labels, fmt.Sprintf(`%s="%s"`, k, v))
+	}
+	labelString := "{" + strings.Join(labels, ",") + "}"
+
+	stream := LokiStream{
+		Labels:  labelString,
+		Entries: []LokiEntry{entry},
+	}
+
+	payload := LokiPayload{
+		Streams: []LokiStream{stream},
+	}
+
+	payloadBytes, err := json.Marshal(payload)
+	if err != nil {
+		return 0, fmt.Errorf("failed to marshal payload: %w", err)
+	}
+
+	req, err := http.NewRequest("POST", w.url, bytes.NewReader(payloadBytes))
+	if err != nil {
+		return 0, fmt.Errorf("failed to create HTTP request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := w.httpClient.Do(req)
+	if err != nil {
+		return 0, fmt.Errorf("failed to send log to Loki: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusNoContent {
+		return 0, fmt.Errorf("received non-204 response from Loki: %d", resp.StatusCode)
+	}
+
+	return len(p), nil
+}