Files
linearvoid/backend/chat/src/metrics/metrics.go
T
zwitschi f73928103a
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fix: linting and go test
2026-08-10 09:30:29 +02:00

278 lines
9.1 KiB
Go

package metrics
import (
"context"
"fmt"
"math"
"net/http"
"strconv"
"strings"
"sync"
"time"
"gorm.io/gorm"
"chat/src/auth"
"chat/src/db"
"chat/src/ws"
)
var requestDurationBuckets = []float64{0.05, 0.1, 0.25, 0.5, 1, 2, 5}
var chatRequestDurationHistogram = newRequestDurationHistogram(requestDurationBuckets)
type requestDurationHistogram struct {
mu sync.Mutex
buckets []float64
counts []uint64
sum float64
total uint64
}
func newRequestDurationHistogram(buckets []float64) *requestDurationHistogram {
return &requestDurationHistogram{
buckets: append([]float64(nil), buckets...),
counts: make([]uint64, len(buckets)+1),
}
}
func (h *requestDurationHistogram) observe(durationSeconds float64) {
h.mu.Lock()
defer h.mu.Unlock()
h.total++
h.sum += durationSeconds
for index, bucket := range h.buckets {
if durationSeconds <= bucket {
h.counts[index]++
return
}
}
h.counts[len(h.counts)-1]++
}
func (h *requestDurationHistogram) snapshot() (counts []uint64, sum float64, total uint64) {
h.mu.Lock()
defer h.mu.Unlock()
counts = append([]uint64(nil), h.counts...)
return counts, h.sum, h.total
}
// ObserveRequestDuration records a chat HTTP request duration in seconds.
func ObserveRequestDuration(duration time.Duration) {
chatRequestDurationHistogram.observe(duration.Seconds())
}
// WrapRequestTiming records request duration for the provided handler.
func WrapRequestTiming(next http.HandlerFunc) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
startedAt := time.Now()
defer func() { ObserveRequestDuration(time.Since(startedAt)) }()
next(w, r)
}
}
// HandleMetrics returns Prometheus-format metrics for the chat service.
func HandleMetrics(gormDB *gorm.DB, redis db.RedisClient, hub *ws.Hub, sessionStore *auth.SessionStore, dbDriver, instanceID string) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
if r.Method != http.MethodGet {
http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
return
}
var storedMessages int64
if gormDB != nil {
_ = gormDB.Model(&db.Message{}).Count(&storedMessages).Error
}
var moderationActions int64
if gormDB != nil {
_ = gormDB.Model(&db.ModerationLog{}).Count(&moderationActions).Error
}
redisEnabled := 0
redisUp := 0
redisClients := 0
redisMemoryUsedBytes := int64(0)
redisMemoryMaxBytes := int64(0)
redisMemoryUsageRatio := 0.0
if redis != nil {
redisEnabled = 1
if err := redis.Ping(context.Background()); err == nil {
redisUp = 1
if info, err := redis.Info(context.Background(), "clients"); err == nil {
for _, line := range strings.Split(info, "\n") {
if strings.HasPrefix(line, "connected_clients:") {
if value, err := strconv.Atoi(strings.TrimSpace(strings.TrimPrefix(line, "connected_clients:"))); err == nil {
redisClients = value
}
break
}
}
}
if info, err := redis.Info(context.Background(), "memory"); err == nil {
if value := parseRedisMemoryBytes(info, "used_memory_human"); value > 0 {
redisMemoryUsedBytes = value
}
if value := parseRedisMemoryBytes(info, "maxmemory_human"); value > 0 {
redisMemoryMaxBytes = value
} else if value := parseRedisMemoryBytes(info, "maxmemory"); value > 0 {
redisMemoryMaxBytes = value
}
if redisMemoryMaxBytes > 0 {
redisMemoryUsageRatio = math.Min(float64(redisMemoryUsedBytes)/float64(redisMemoryMaxBytes), 1.0)
}
}
}
}
connectedClients := 0
dmsSent := int64(0)
if hub != nil {
connectedClients = hub.ConnectedClients()
dmsSent = hub.DMsSent
}
activeSessions := 0
if sessionStore != nil {
activeSessions = sessionStore.CountActive()
}
w.Header().Set("Content-Type", "text/plain; version=0.0.4; charset=utf-8")
writeLine := func(name string, value any) {
fmt.Fprintf(w, "%s %v\n", name, value)
}
fmt.Fprintln(w, "# HELP linearvoid_chat_connected_clients Current connected WebSocket clients.")
fmt.Fprintln(w, "# TYPE linearvoid_chat_connected_clients gauge")
writeLine("linearvoid_chat_connected_clients", connectedClients)
fmt.Fprintln(w, "# HELP linearvoid_chat_messages_total Total stored chat messages.")
fmt.Fprintln(w, "# TYPE linearvoid_chat_messages_total gauge")
writeLine("linearvoid_chat_messages_total", storedMessages)
fmt.Fprintln(w, "# HELP linearvoid_chat_dms_total Total private messages sent.")
fmt.Fprintln(w, "# TYPE linearvoid_chat_dms_total counter")
writeLine("linearvoid_chat_dms_total", dmsSent)
fmt.Fprintln(w, "# HELP linearvoid_chat_moderation_actions_total Total moderation log entries.")
fmt.Fprintln(w, "# TYPE linearvoid_chat_moderation_actions_total gauge")
writeLine("linearvoid_chat_moderation_actions_total", moderationActions)
fmt.Fprintln(w, "# HELP linearvoid_chat_redis_enabled Redis configured for chat service.")
fmt.Fprintln(w, "# TYPE linearvoid_chat_redis_enabled gauge")
writeLine("linearvoid_chat_redis_enabled", redisEnabled)
fmt.Fprintln(w, "# HELP linearvoid_chat_redis_up Redis reachable from chat service.")
fmt.Fprintln(w, "# TYPE linearvoid_chat_redis_up gauge")
writeLine("linearvoid_chat_redis_up", redisUp)
fmt.Fprintln(w, "# HELP linearvoid_chat_redis_connected_clients Redis connected client count seen by chat service.")
fmt.Fprintln(w, "# TYPE linearvoid_chat_redis_connected_clients gauge")
writeLine("linearvoid_chat_redis_connected_clients", redisClients)
fmt.Fprintln(w, "# HELP linearvoid_chat_redis_memory_used_bytes Redis used memory reported by INFO memory.")
fmt.Fprintln(w, "# TYPE linearvoid_chat_redis_memory_used_bytes gauge")
writeLine("linearvoid_chat_redis_memory_used_bytes", redisMemoryUsedBytes)
fmt.Fprintln(w, "# HELP linearvoid_chat_redis_memory_max_bytes Redis maxmemory limit reported by INFO memory.")
fmt.Fprintln(w, "# TYPE linearvoid_chat_redis_memory_max_bytes gauge")
writeLine("linearvoid_chat_redis_memory_max_bytes", redisMemoryMaxBytes)
fmt.Fprintln(w, "# HELP linearvoid_chat_redis_memory_usage_ratio Redis memory usage ratio (used / max).")
fmt.Fprintln(w, "# TYPE linearvoid_chat_redis_memory_usage_ratio gauge")
writeLine("linearvoid_chat_redis_memory_usage_ratio", redisMemoryUsageRatio)
fmt.Fprintln(w, "# HELP linearvoid_chat_admin_sessions_active Active unexpired admin sessions.")
fmt.Fprintln(w, "# TYPE linearvoid_chat_admin_sessions_active gauge")
writeLine("linearvoid_chat_admin_sessions_active", activeSessions)
fmt.Fprintln(w, "# HELP linearvoid_chat_build_info Static build info for chat service.")
fmt.Fprintln(w, "# TYPE linearvoid_chat_build_info gauge")
fmt.Fprintf(w, "linearvoid_chat_build_info{service=\"chat\",database_driver=\"%s\",instance_id=\"%s\"} 1\n", dbDriver, instanceID)
counts, sum, total := chatRequestDurationHistogram.snapshot()
fmt.Fprintln(w, "# HELP linearvoid_chat_request_duration_seconds HTTP request duration for chat API handlers.")
fmt.Fprintln(w, "# TYPE linearvoid_chat_request_duration_seconds histogram")
cumulative := uint64(0)
for index, bucket := range requestDurationBuckets {
cumulative += counts[index]
fmt.Fprintf(w, "linearvoid_chat_request_duration_seconds_bucket{le=\"%g\"} %d\n", bucket, cumulative)
}
cumulative += counts[len(counts)-1]
fmt.Fprintf(w, "linearvoid_chat_request_duration_seconds_bucket{le=\"+Inf\"} %d\n", cumulative)
fmt.Fprintf(w, "linearvoid_chat_request_duration_seconds_sum %g\n", sum)
fmt.Fprintf(w, "linearvoid_chat_request_duration_seconds_count %d\n", total)
}
}
// HandleHealth returns a simple health check endpoint.
func HandleHealth() http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(http.StatusOK)
fmt.Fprint(w, `{"status":"healthy","service":"chat","timestamp":"`+time.Now().UTC().Format(time.RFC3339)+`"}`)
}
}
// HandleNotFound returns a 404 JSON response for all unhandled paths.
func HandleNotFound() http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(http.StatusNotFound)
fmt.Fprint(w, `{"error":"not found"}`)
}
}
func parseRedisMemoryBytes(info, key string) int64 {
for _, line := range strings.Split(info, "\n") {
if !strings.HasPrefix(line, key+":") {
continue
}
value := strings.TrimSpace(strings.TrimPrefix(line, key+":"))
if value == "" {
return 0
}
if raw, err := strconv.ParseInt(value, 10, 64); err == nil {
return raw
}
return parseHumanBytes(value)
}
return 0
}
func parseHumanBytes(value string) int64 {
value = strings.TrimSpace(strings.ToUpper(value))
if value == "" {
return 0
}
multiplier := float64(1)
suffixes := map[string]float64{
"B": 1,
"K": 1024,
"KB": 1024,
"M": 1024 * 1024,
"MB": 1024 * 1024,
"G": 1024 * 1024 * 1024,
"GB": 1024 * 1024 * 1024,
"T": 1024 * 1024 * 1024 * 1024,
"TB": 1024 * 1024 * 1024 * 1024,
}
for suffix, factor := range suffixes {
if strings.HasSuffix(value, suffix) {
multiplier = factor
value = strings.TrimSpace(strings.TrimSuffix(value, suffix))
break
}
}
parsed, err := strconv.ParseFloat(value, 64)
if err != nil {
return 0
}
return int64(parsed * multiplier)
}