feat(agent) multi-driver db monitoring, hot-plug config, release pipeline

internal/collectors/redis/redis.go

@@ -0,0 +1,78 @@
+package redis
+
+import (
+	"context"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/redis/go-redis/v9"
+
+	"bugs.watch/agent/internal/aggregate"
+)
+
+// Collector queries Redis INFO each sample interval.
+// All queries run under a 3-second timeout; any failure is silently skipped.
+// Metrics mapping:
+//   db_conn_pct        → used_memory / maxmemory * 100 (skipped when maxmemory=0)
+//   db_threads_running → connected_clients
+//   db_size_bytes      → used_memory
+type Collector struct {
+	client *redis.Client
+}
+
+func New(addr string) (*Collector, error) {
+	opts, err := redis.ParseURL(addr)
+	if err != nil {
+		return nil, err
+	}
+	opts.DialTimeout = 3 * time.Second
+	opts.ReadTimeout = 3 * time.Second
+	opts.WriteTimeout = 3 * time.Second
+	return &Collector{client: redis.NewClient(opts)}, nil
+}
+
+func (c *Collector) Name() string { return "redis" }
+
+func (c *Collector) Close() { c.client.Close() }
+
+func (c *Collector) Collect(window *aggregate.Window) {
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	info, err := c.client.Info(ctx, "memory", "clients").Result()
+	if err != nil {
+		return
+	}
+
+	fields := parseInfo(info)
+
+	usedMem, _ := strconv.ParseUint(fields["used_memory"], 10, 64)
+	maxMem, _ := strconv.ParseUint(fields["maxmemory"], 10, 64)
+	clients, _ := strconv.ParseUint(fields["connected_clients"], 10, 64)
+
+	if usedMem > 0 {
+		window.SetDBSizeBytes(usedMem)
+	}
+	if clients > 0 {
+		window.AddDBThreadsRunning(float64(clients))
+	}
+	if maxMem > 0 && usedMem > 0 {
+		window.AddDBConnPct(float64(usedMem) / float64(maxMem) * 100)
+	}
+}
+
+func parseInfo(s string) map[string]string {
+	out := make(map[string]string)
+	for _, line := range strings.Split(s, "\n") {
+		line = strings.TrimSpace(line)
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+		k, v, ok := strings.Cut(line, ":")
+		if ok {
+			out[strings.TrimSpace(k)] = strings.TrimSpace(v)
+		}
+	}
+	return out
+}