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

.gitea/workflows/build.yml

@@ -0,0 +1,45 @@
+name: build-and-release
+
+on:
+  push:
+    tags:
+      - "v*"
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: '1.22'
+
+      - name: Build binaries
+        run: make build-all
+
+      - name: Create release
+        id: release
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.NODE_AUTH_TOKEN }}
+        run: |
+          TAG="${{ github.ref_name }}"
+          RESPONSE=$(curl -sf -X POST \
+            -H "Authorization: token ${NODE_AUTH_TOKEN}" \
+            -H "Content-Type: application/json" \
+            -d "{\"tag_name\":\"${TAG}\",\"name\":\"${TAG}\",\"draft\":false,\"prerelease\":false}" \
+            "${{ github.server_url }}/api/v1/repos/${{ github.repository }}/releases")
+          echo "id=$(echo "$RESPONSE" | jq -r .id)" >> $GITHUB_OUTPUT
+
+      - name: Upload binaries
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.NODE_AUTH_TOKEN }}
+        run: |
+          for FILE in dist/bugswatch-*; do
+            curl -sf -X POST \
+              -H "Authorization: token ${NODE_AUTH_TOKEN}" \
+              -H "Content-Type: application/octet-stream" \
+              --data-binary "@${FILE}" \
+              "${{ github.server_url }}/api/v1/repos/${{ github.repository }}/releases/${{ steps.release.outputs.id }}/assets?name=$(basename ${FILE})"
+          done

LICENSE

@@ -0,0 +1,18 @@
+MIT No Attribution
+
+Copyright 2025 bugs.watch
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

Makefile

@@ -0,0 +1,19 @@
+VERSION ?= $(shell git describe --tags --always --dirty 2>/dev/null || echo dev)
+LDFLAGS = -ldflags="-s -w -X main.version=$(VERSION)"
+OUT = dist
+
+.PHONY: build build-all clean
+
+build:
+	go mod tidy
+	CGO_ENABLED=0 go build $(LDFLAGS) -o $(OUT)/bugswatch ./cmd/agent
+
+build-all:
+	go mod tidy
+	CGO_ENABLED=0 GOOS=linux  GOARCH=amd64 go build $(LDFLAGS) -o $(OUT)/bugswatch-linux-amd64  ./cmd/agent
+	CGO_ENABLED=0 GOOS=linux  GOARCH=arm64 go build $(LDFLAGS) -o $(OUT)/bugswatch-linux-arm64  ./cmd/agent
+	CGO_ENABLED=0 GOOS=darwin GOARCH=amd64 go build $(LDFLAGS) -o $(OUT)/bugswatch-darwin-amd64 ./cmd/agent
+	CGO_ENABLED=0 GOOS=darwin GOARCH=arm64 go build $(LDFLAGS) -o $(OUT)/bugswatch-darwin-arm64 ./cmd/agent
+
+clean:
+	rm -rf $(OUT)

cmd/agent/main.go

@@ -2,24 +2,144 @@ package main
 
 import (
 	"context"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"log"
 	"os"
 	"os/signal"
 	"syscall"
 
 	"bugs.watch/agent/internal/agent"
+	"bugs.watch/agent/internal/config"
+	"bugs.watch/agent/internal/dbmanager"
 )
 
 func main() {
+	// Peek at the first arg before flag parsing to detect sub-commands.
+	if len(os.Args) > 1 && os.Args[1] == "db" {
+		runDBCmd(os.Args[2:])
+		return
+	}
+
+	cfg, err := config.Load()
+	if err != nil {
+		log.Fatalf("configuration error: %v", err)
+	}
+
+	flag.StringVar(&cfg.DBConfigPath, "db-config", cfg.DBConfigPath,
+		"path to databases.json (default /etc/bugswatch/databases.json, or $BUGSWATCH_DB_CONFIG)")
+	flag.Parse()
+
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
 	sigCh := make(chan os.Signal, 1)
 	signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM)
-
 	go func() {
 		<-sigCh
 		cancel()
 	}()
 
-	agent.Run(ctx)
+	agent.Run(ctx, cfg)
+}
+
+// ── db sub-commands ──────────────────────────────────────────────────────────
+
+func runDBCmd(args []string) {
+	if len(args) == 0 {
+		fmt.Fprintln(os.Stderr, "usage: bugswatch db <add|remove|list> [args]")
+		os.Exit(1)
+	}
+
+	// Allow --db-config as the first flag of a db sub-command.
+	cfgPath := config.DefaultDBConfigPath
+	if v := os.Getenv("BUGSWATCH_DB_CONFIG"); v != "" {
+		cfgPath = v
+	}
+	if len(args) >= 2 && args[0] == "--db-config" {
+		cfgPath = args[1]
+		args = args[2:]
+	}
+
+	switch args[0] {
+	case "add":
+		if len(args) < 3 {
+			fmt.Fprintln(os.Stderr, "usage: bugswatch db add <driver> <url>")
+			fmt.Fprintln(os.Stderr, "drivers: mysql, mariadb, postgres, redis, mongodb, sqlite")
+			os.Exit(1)
+		}
+		dbAdd(cfgPath, args[1], args[2])
+
+	case "remove":
+		if len(args) < 2 {
+			fmt.Fprintln(os.Stderr, "usage: bugswatch db remove <driver>")
+			os.Exit(1)
+		}
+		dbRemove(cfgPath, args[1])
+
+	case "list":
+		dbList(cfgPath)
+
+	default:
+		fmt.Fprintf(os.Stderr, "unknown db command %q\n", args[0])
+		os.Exit(1)
+	}
+}
+
+func dbAdd(cfgPath, driver, url string) {
+	entries, err := dbmanager.ReadEntries(cfgPath)
+	if err != nil {
+		log.Fatalf("read config: %v", err)
+	}
+
+	found := false
+	for i, e := range entries {
+		if e.Driver == driver {
+			entries[i].URL = url
+			found = true
+			break
+		}
+	}
+	if !found {
+		entries = append(entries, dbmanager.Entry{Driver: driver, URL: url})
+	}
+
+	if err := dbmanager.WriteEntries(cfgPath, entries); err != nil {
+		log.Fatalf("write config: %v", err)
+	}
+	fmt.Printf("added %s → %s\n", driver, cfgPath)
+}
+
+func dbRemove(cfgPath, driver string) {
+	entries, err := dbmanager.ReadEntries(cfgPath)
+	if err != nil {
+		log.Fatalf("read config: %v", err)
+	}
+
+	next := entries[:0]
+	for _, e := range entries {
+		if e.Driver != driver {
+			next = append(next, e)
+		}
+	}
+
+	if err := dbmanager.WriteEntries(cfgPath, next); err != nil {
+		log.Fatalf("write config: %v", err)
+	}
+	fmt.Printf("removed %s from %s\n", driver, cfgPath)
+}
+
+func dbList(cfgPath string) {
+	entries, err := dbmanager.ReadEntries(cfgPath)
+	if err != nil {
+		log.Fatalf("read config: %v", err)
+	}
+	if len(entries) == 0 {
+		fmt.Println("no database monitors configured")
+		return
+	}
+	enc := json.NewEncoder(os.Stdout)
+	enc.SetIndent("", "  ")
+	enc.Encode(entries)
 }

go.mod

@@ -1,3 +1,10 @@
 module bugs.watch/agent
 
 go 1.22.12
+
+require (
+	github.com/go-sql-driver/mysql v1.8.1
+	github.com/lib/pq v1.10.9
+	github.com/redis/go-redis/v9 v9.7.3
+	go.mongodb.org/mongo-driver v1.17.1
+)

internal/agent/agent.go

@@ -11,6 +11,8 @@ import (
 	"bugs.watch/agent/internal/collectors/disk"
 	"bugs.watch/agent/internal/collectors/memory"
 	"bugs.watch/agent/internal/collectors/uptime"
+	"bugs.watch/agent/internal/config"
+	"bugs.watch/agent/internal/dbmanager"
 	"bugs.watch/agent/internal/sender"
 )
 
@@ -19,13 +21,12 @@ const (
 	windowDuration = 60 * time.Second
 )
 
-func Run(ctx context.Context) {
+func Run(ctx context.Context, cfg config.Config) {
 	log.Println("bugswatch agent starting")
+	log.Printf("db config: %s", cfg.DBConfigPath)
 
-	// Aggregation window
 	window := aggregate.NewWindow()
 
-	// Register collectors
 	cols := []collectors.Collector{
 		uptime.New(),
 		cpu.New(),
@@ -33,8 +34,10 @@ func Run(ctx context.Context) {
 		disk.New(),
 	}
 
-	// Sender (HTTP or logging)
-	snd := sender.NewHTTPSender("http://172.17.0.1:5173/api/health")
+	mgr := dbmanager.New(cfg.DBConfigPath)
+	go mgr.Watch(ctx)
+
+	snd := sender.NewHTTPSender(cfg)
 
 	ticker := time.NewTicker(sampleInterval)
 	defer ticker.Stop()
@@ -43,21 +46,19 @@ func Run(ctx context.Context) {
 		select {
 		case <-ctx.Done():
 			log.Println("bugswatch agent shutting down")
-
-			// Best-effort final flush with bounded timeout
 			shutdownCtx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
 			defer cancel()
-
-			emitSnapshot(shutdownCtx, snd, window)
+			emitSnapshot(shutdownCtx, snd, window, mgr)
 			return
 
 		case <-ticker.C:
 			for _, c := range cols {
 				c.Collect(window)
 			}
+			mgr.Collect(window)
 
 			if window.Ready(windowDuration) {
-				emitSnapshot(ctx, snd, window)
+				emitSnapshot(ctx, snd, window, mgr)
 				window = aggregate.NewWindow()
 			}
 		}
@@ -68,6 +69,7 @@ func emitSnapshot(
 	ctx context.Context,
 	snd sender.Sender,
 	window *aggregate.Window,
+	mgr *dbmanager.Manager,
 ) {
 	snap := window.Snapshot()
 	_ = snd.Send(ctx, snap)

internal/aggregate/window.go

@@ -15,6 +15,16 @@ type Window struct {
 	diskCount uint64
 
 	uptime uint64
+
+	// DB metrics — populated only when a DB collector is registered.
+	hasDB              bool
+	dbDriver           uint8
+	dbConnPctSum       float64
+	dbConnPctCount     uint64
+	dbThreadsSum       float64
+	dbThreadsCount     uint64
+	dbSlowQueriesDelta uint64
+	dbSizeBytes        uint64
 }
 
 type Snapshot struct {
@@ -23,14 +33,18 @@ type Snapshot struct {
 	CPUAvg  float64
 	MemAvg  float64
 	DiskAvg float64
-
 	Uptime  uint64
+
+	// nil when DB monitoring is not enabled.
+	DBDriver         *uint8
+	DBConnPct        *float64
+	DBThreadsRunning *float64
+	DBSlowQueries    *uint64
+	DBSizeBytes      *uint64
 }
 
 func NewWindow() *Window {
-	return &Window{
-		start: time.Now(),
-	}
+	return &Window{start: time.Now()}
 }
 
 func (w *Window) AddCPU(value float64) {
@@ -43,10 +57,41 @@ func (w *Window) AddMemory(value float64) {
 	w.memCount++
 }
 
+func (w *Window) AddDisk(value float64) {
+	w.diskSum += value
+	w.diskCount++
+}
+
 func (w *Window) SetUptime(value uint64) {
 	w.uptime = value
 }
 
+func (w *Window) AddDBConnPct(v float64) {
+	w.dbConnPctSum += v
+	w.dbConnPctCount++
+	w.hasDB = true
+}
+
+func (w *Window) AddDBThreadsRunning(v float64) {
+	w.dbThreadsSum += v
+	w.dbThreadsCount++
+}
+
+func (w *Window) AddDBSlowQueriesDelta(v uint64) {
+	w.dbSlowQueriesDelta += v
+}
+
+func (w *Window) SetDBSizeBytes(v uint64) {
+	w.dbSizeBytes = v
+	w.hasDB = true
+}
+
+// SetDBDriver records the numeric driver identifier (see dbmanager.Driver* constants).
+// When multiple collectors are active this is called once per window by the manager.
+func (w *Window) SetDBDriver(v uint8) {
+	w.dbDriver = v
+}
+
 func (w *Window) Ready(windowDuration time.Duration) bool {
 	return time.Since(w.start) >= windowDuration
 }
@@ -67,16 +112,36 @@ func (w *Window) Snapshot() Snapshot {
 		diskAvg = w.diskSum / float64(w.diskCount)
 	}
 
-	return Snapshot{
+	snap := Snapshot{
 		Timestamp: time.Now(),
 		CPUAvg:    cpuAvg,
 		MemAvg:    memAvg,
 		DiskAvg:   diskAvg,
 		Uptime:    w.uptime,
 	}
-}
 
-func (w *Window) AddDisk(value float64) {
-	w.diskSum += value
-	w.diskCount++
+	if w.hasDB {
+		driver := w.dbDriver
+
+		var connPct float64
+		if w.dbConnPctCount > 0 {
+			connPct = w.dbConnPctSum / float64(w.dbConnPctCount)
+		}
+
+		var threads float64
+		if w.dbThreadsCount > 0 {
+			threads = w.dbThreadsSum / float64(w.dbThreadsCount)
+		}
+
+		slow := w.dbSlowQueriesDelta
+		sizeBytes := w.dbSizeBytes
+
+		snap.DBDriver = &driver
+		snap.DBConnPct = &connPct
+		snap.DBThreadsRunning = &threads
+		snap.DBSlowQueries = &slow
+		snap.DBSizeBytes = &sizeBytes
+	}
+
+	return snap
 }

internal/collectors/mongodb/mongodb.go

@@ -0,0 +1,94 @@
+package mongodb
+
+import (
+	"context"
+	"time"
+
+	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/mongo"
+	"go.mongodb.org/mongo-driver/mongo/options"
+
+	"bugs.watch/agent/internal/aggregate"
+)
+
+// Collector queries MongoDB serverStatus and listDatabases each sample interval.
+// All queries run under a 3-second timeout; any failure is silently skipped.
+// Metrics mapping:
+//   db_conn_pct        → current / (current + available) * 100
+//   db_threads_running → connections.current
+//   db_size_bytes      → totalSize from listDatabases
+type Collector struct {
+	client *mongo.Client
+}
+
+func New(uri string) (*Collector, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	client, err := mongo.Connect(ctx, options.Client().ApplyURI(uri).
+		SetConnectTimeout(3*time.Second).
+		SetServerSelectionTimeout(3*time.Second))
+	if err != nil {
+		return nil, err
+	}
+	return &Collector{client: client}, nil
+}
+
+func (c *Collector) Name() string { return "mongodb" }
+
+func (c *Collector) Close() {
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
+	c.client.Disconnect(ctx)
+}
+
+func (c *Collector) Collect(window *aggregate.Window) {
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	admin := c.client.Database("admin")
+
+	var status bson.M
+	if err := admin.RunCommand(ctx, bson.D{
+		{Key: "serverStatus", Value: 1},
+		{Key: "repl", Value: 0},
+		{Key: "metrics", Value: 0},
+		{Key: "locks", Value: 0},
+	}).Decode(&status); err != nil {
+		return
+	}
+
+	if conns, ok := status["connections"].(bson.M); ok {
+		current := toFloat64(conns["current"])
+		available := toFloat64(conns["available"])
+		total := current + available
+		if total > 0 {
+			window.AddDBConnPct(current / total * 100)
+		}
+		if current > 0 {
+			window.AddDBThreadsRunning(current)
+		}
+	}
+
+	var listResult bson.M
+	if err := admin.RunCommand(ctx, bson.D{
+		{Key: "listDatabases", Value: 1},
+		{Key: "nameOnly", Value: false},
+	}).Decode(&listResult); err == nil {
+		if totalSize := toFloat64(listResult["totalSize"]); totalSize > 0 {
+			window.SetDBSizeBytes(uint64(totalSize))
+		}
+	}
+}
+
+func toFloat64(v interface{}) float64 {
+	switch x := v.(type) {
+	case int32:
+		return float64(x)
+	case int64:
+		return float64(x)
+	case float64:
+		return x
+	}
+	return 0
+}

internal/collectors/mysql/mysql.go

@@ -0,0 +1,92 @@
+package mysql
+
+import (
+	"context"
+	"database/sql"
+	"strconv"
+	"time"
+
+	_ "github.com/go-sql-driver/mysql"
+
+	"bugs.watch/agent/internal/aggregate"
+)
+
+// Collector queries MySQL global status each sample interval.
+// All queries run under a 3-second timeout; any failure is silently skipped.
+type Collector struct {
+	db              *sql.DB
+	prevSlowQueries uint64
+	hasPrev         bool
+}
+
+func New(dsn string) (*Collector, error) {
+	db, err := sql.Open("mysql", dsn)
+	if err != nil {
+		return nil, err
+	}
+	db.SetMaxOpenConns(2)
+	db.SetMaxIdleConns(1)
+	db.SetConnMaxLifetime(5 * time.Minute)
+	return &Collector{db: db}, nil
+}
+
+func (c *Collector) Name() string { return "mysql" }
+
+func (c *Collector) Close() { c.db.Close() }
+
+func (c *Collector) Collect(window *aggregate.Window) {
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	rows, err := c.db.QueryContext(ctx,
+		"SHOW GLOBAL STATUS WHERE Variable_name IN ('Threads_connected','Threads_running','Slow_queries')",
+	)
+	if err != nil {
+		return
+	}
+	defer rows.Close()
+
+	vars := make(map[string]uint64, 3)
+	for rows.Next() {
+		var name, raw string
+		if err := rows.Scan(&name, &raw); err != nil {
+			continue
+		}
+		if v, err := strconv.ParseUint(raw, 10, 64); err == nil {
+			vars[name] = v
+		}
+	}
+	if err := rows.Err(); err != nil {
+		return
+	}
+
+	var maxConn uint64
+	if err := c.db.QueryRowContext(ctx, "SELECT @@max_connections").Scan(&maxConn); err != nil || maxConn == 0 {
+		maxConn = 1
+	}
+
+	connPct := float64(vars["Threads_connected"]) / float64(maxConn) * 100
+	window.AddDBConnPct(connPct)
+	window.AddDBThreadsRunning(float64(vars["Threads_running"]))
+
+	slow := vars["Slow_queries"]
+	if c.hasPrev {
+		var delta uint64
+		if slow >= c.prevSlowQueries {
+			delta = slow - c.prevSlowQueries
+		}
+		window.AddDBSlowQueriesDelta(delta)
+	}
+	c.prevSlowQueries = slow
+	c.hasPrev = true
+
+	var sizeBytes uint64
+	err = c.db.QueryRowContext(ctx,
+		"SELECT COALESCE(SUM(data_length + index_length), 0)"+
+			" FROM information_schema.tables"+
+			" WHERE table_schema NOT IN ('information_schema','performance_schema','mysql','sys')",
+	).Scan(&sizeBytes)
+	if err == nil {
+		window.SetDBSizeBytes(sizeBytes)
+	}
+}

internal/collectors/postgres/postgres.go

@@ -0,0 +1,63 @@
+package postgres
+
+import (
+	"context"
+	"database/sql"
+	"time"
+
+	_ "github.com/lib/pq"
+
+	"bugs.watch/agent/internal/aggregate"
+)
+
+// Collector queries PostgreSQL status each sample interval.
+// All queries run under a 3-second timeout; any failure is silently skipped.
+type Collector struct {
+	db *sql.DB
+}
+
+func New(dsn string) (*Collector, error) {
+	db, err := sql.Open("postgres", dsn)
+	if err != nil {
+		return nil, err
+	}
+	db.SetMaxOpenConns(2)
+	db.SetMaxIdleConns(1)
+	db.SetConnMaxLifetime(5 * time.Minute)
+	return &Collector{db: db}, nil
+}
+
+func (c *Collector) Name() string { return "postgres" }
+
+func (c *Collector) Close() { c.db.Close() }
+
+func (c *Collector) Collect(window *aggregate.Window) {
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	// pg_stat_database is readable by any user for their own database.
+	var numBackends, maxConn int
+	err := c.db.QueryRowContext(ctx,
+		`SELECT d.numbackends, s.setting::int
+		 FROM pg_stat_database d, pg_settings s
+		 WHERE d.datname = current_database() AND s.name = 'max_connections'`,
+	).Scan(&numBackends, &maxConn)
+	if err == nil && maxConn > 0 {
+		window.AddDBConnPct(float64(numBackends) / float64(maxConn) * 100)
+	}
+
+	// pg_stat_activity requires pg_monitor role (PG 10+); silently skip on error.
+	var activeQueries int
+	if err := c.db.QueryRowContext(ctx,
+		`SELECT count(*) FROM pg_stat_activity WHERE state = 'active'`,
+	).Scan(&activeQueries); err == nil {
+		window.AddDBThreadsRunning(float64(activeQueries))
+	}
+
+	var sizeBytes int64
+	if err := c.db.QueryRowContext(ctx,
+		`SELECT pg_database_size(current_database())`,
+	).Scan(&sizeBytes); err == nil {
+		window.SetDBSizeBytes(uint64(sizeBytes))
+	}
+}

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
+}

internal/collectors/sqlite/sqlite.go

@@ -0,0 +1,30 @@
+package sqlite
+
+import (
+	"os"
+
+	"bugs.watch/agent/internal/aggregate"
+)
+
+// Collector reports the on-disk size of a SQLite database file.
+// No driver or connection is needed; we simply stat the file.
+// Failures are silently skipped.
+type Collector struct {
+	path string
+}
+
+func New(path string) *Collector {
+	return &Collector{path: path}
+}
+
+func (c *Collector) Name() string { return "sqlite" }
+
+func (c *Collector) Close() {}
+
+func (c *Collector) Collect(window *aggregate.Window) {
+	info, err := os.Stat(c.path)
+	if err != nil {
+		return
+	}
+	window.SetDBSizeBytes(uint64(info.Size()))
+}

internal/config/config.go

@@ -0,0 +1,45 @@
+package config
+
+import (
+	"errors"
+	"os"
+)
+
+const DefaultDBConfigPath = "/etc/bugswatch/databases.json"
+
+type Config struct {
+	Endpoint     string
+	AgentID      string
+	APIToken     string
+	HostID       string
+	Env          string
+	DBConfigPath string
+}
+
+func Load() (Config, error) {
+	dbConfig := os.Getenv("BUGSWATCH_DB_CONFIG")
+	if dbConfig == "" {
+		dbConfig = DefaultDBConfigPath
+	}
+
+	cfg := Config{
+		Endpoint:     os.Getenv("BUGSWATCH_ENDPOINT"),
+		AgentID:      os.Getenv("BUGSWATCH_AGENT_ID"),
+		APIToken:     os.Getenv("BUGSWATCH_API_TOKEN"),
+		HostID:       os.Getenv("BUGSWATCH_HOST_ID"),
+		Env:          os.Getenv("BUGSWATCH_ENVIRONMENT"),
+		DBConfigPath: dbConfig,
+	}
+
+	if cfg.Endpoint == "" {
+		return Config{}, errors.New("BUGSWATCH_ENDPOINT not set")
+	}
+	if cfg.AgentID == "" {
+		return Config{}, errors.New("BUGSWATCH_AGENT_ID not set")
+	}
+	if cfg.APIToken == "" {
+		return Config{}, errors.New("BUGSWATCH_API_TOKEN not set")
+	}
+
+	return cfg, nil
+}

internal/dbmanager/manager.go

@@ -0,0 +1,203 @@
+package dbmanager
+
+import (
+	"context"
+	"crypto/md5"
+	"encoding/json"
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+	"sync"
+	"time"
+
+	"bugs.watch/agent/internal/aggregate"
+	"bugs.watch/agent/internal/collectors"
+	mongocol "bugs.watch/agent/internal/collectors/mongodb"
+	mysqlcol "bugs.watch/agent/internal/collectors/mysql"
+	pgcol "bugs.watch/agent/internal/collectors/postgres"
+	rediscol "bugs.watch/agent/internal/collectors/redis"
+	sqlitecol "bugs.watch/agent/internal/collectors/sqlite"
+)
+
+// Driver type identifiers — used as the db_driver field in the health payload
+// so the dashboard can render the correct icon without parsing strings.
+const (
+	DriverNone      uint8 = 0
+	DriverMySQL     uint8 = 1 // also MariaDB
+	DriverPostgres  uint8 = 2
+	DriverRedis     uint8 = 3
+	DriverMongoDB   uint8 = 4
+	DriverSQLite    uint8 = 5
+)
+
+// Entry is one database config record in databases.json.
+type Entry struct {
+	Driver string `json:"driver"`
+	URL    string `json:"url"`
+}
+
+type dbCollector interface {
+	collectors.Collector
+	Close()
+}
+
+// Manager watches a config file and hot-swaps DB collectors without agent restart.
+// Collect() is safe to call concurrently with Watch().
+type Manager struct {
+	mu         sync.RWMutex
+	active     []dbCollector
+	configPath string
+	lastHash   [16]byte
+}
+
+func New(configPath string) *Manager {
+	return &Manager{configPath: configPath}
+}
+
+// Watch polls the config file every 30 seconds and reloads on change.
+// Blocks until ctx is cancelled.
+func (m *Manager) Watch(ctx context.Context) {
+	m.reload()
+
+	ticker := time.NewTicker(30 * time.Second)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			m.swap(nil)
+			return
+		case <-ticker.C:
+			m.reload()
+		}
+	}
+}
+
+// Collect runs all active DB collectors against the window.
+// Holds RLock for the full duration so swaps never race with in-progress queries.
+func (m *Manager) Collect(window *aggregate.Window) {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	if len(m.active) == 0 {
+		return
+	}
+	window.SetDBDriver(m.driverID(m.active[0].Name()))
+	for _, c := range m.active {
+		c.Collect(window)
+	}
+}
+
+func (m *Manager) driverID(name string) uint8 {
+	switch name {
+	case "mysql", "mariadb":
+		return DriverMySQL
+	case "postgres":
+		return DriverPostgres
+	case "redis":
+		return DriverRedis
+	case "mongodb":
+		return DriverMongoDB
+	case "sqlite":
+		return DriverSQLite
+	default:
+		return DriverNone
+	}
+}
+
+func (m *Manager) reload() {
+	data, err := os.ReadFile(m.configPath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			m.swap(nil)
+		}
+		return
+	}
+
+	hash := md5.Sum(data)
+	m.mu.RLock()
+	unchanged := hash == m.lastHash
+	m.mu.RUnlock()
+	if unchanged {
+		return
+	}
+
+	var entries []Entry
+	if err := json.Unmarshal(data, &entries); err != nil {
+		log.Printf("dbmanager: invalid config: %v", err)
+		return
+	}
+
+	var next []dbCollector
+	for _, e := range entries {
+		c, err := newCollector(e)
+		if err != nil {
+			log.Printf("dbmanager: %s: %v", e.Driver, err)
+			continue
+		}
+		next = append(next, c)
+		log.Printf("dbmanager: loaded %s", e.Driver)
+	}
+
+	m.swap(next)
+
+	m.mu.Lock()
+	m.lastHash = hash
+	m.mu.Unlock()
+}
+
+func (m *Manager) swap(next []dbCollector) {
+	m.mu.Lock()
+	old := m.active
+	m.active = next
+	m.mu.Unlock()
+
+	for _, c := range old {
+		c.Close()
+	}
+}
+
+func newCollector(e Entry) (dbCollector, error) {
+	switch e.Driver {
+	case "mysql", "mariadb":
+		return mysqlcol.New(e.URL)
+	case "postgres", "postgresql":
+		return pgcol.New(e.URL)
+	case "redis":
+		return rediscol.New(e.URL)
+	case "mongodb":
+		return mongocol.New(e.URL)
+	case "sqlite":
+		return sqlitecol.New(e.URL), nil
+	default:
+		return nil, fmt.Errorf("unknown driver %q (supported: mysql, mariadb, postgres, redis, mongodb, sqlite)", e.Driver)
+	}
+}
+
+// ReadEntries reads the config file, returning an empty slice if it doesn't exist.
+func ReadEntries(configPath string) ([]Entry, error) {
+	data, err := os.ReadFile(configPath)
+	if os.IsNotExist(err) {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	var entries []Entry
+	if err := json.Unmarshal(data, &entries); err != nil {
+		return nil, err
+	}
+	return entries, nil
+}
+
+// WriteEntries writes entries to the config file, creating the directory if needed.
+func WriteEntries(configPath string, entries []Entry) error {
+	if err := os.MkdirAll(filepath.Dir(configPath), 0755); err != nil {
+		return err
+	}
+	data, err := json.MarshalIndent(entries, "", "  ")
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(configPath, data, 0644)
+}

internal/sender/http.go

@@ -7,20 +7,27 @@ import (
 	"net/http"
 	"time"
 
+	"bugs.watch/agent/internal/config"
 	"bugs.watch/agent/internal/aggregate"
 )
 
 type HTTPSender struct {
 	client   *http.Client
 	endpoint string
+	token    string
+	hostID   string
+	env      string
 }
 
-func NewHTTPSender(endpoint string) *HTTPSender {
+func NewHTTPSender(cfg config.Config) *HTTPSender {
 	return &HTTPSender{
 		client: &http.Client{
 			Timeout: 5 * time.Second,
 		},
-		endpoint: endpoint,
+		endpoint: cfg.Endpoint + "/api/v1/agents/" + cfg.AgentID,
+		token:    cfg.APIToken,
+		hostID:   cfg.HostID,
+		env:      cfg.Env,
 	}
 }
 
@@ -31,6 +38,13 @@ func (s *HTTPSender) Send(ctx context.Context, snap aggregate.Snapshot) error {
 		MemAvg:           snap.MemAvg,
 		DiskAvg:          snap.DiskAvg,
 		Uptime:           snap.Uptime,
+		HostID:           s.hostID,
+		Environment:      s.env,
+		DBDriver:         snap.DBDriver,
+		DBConnPct:        snap.DBConnPct,
+		DBThreadsRunning: snap.DBThreadsRunning,
+		DBSlowQueries:    snap.DBSlowQueries,
+		DBSizeBytes:      snap.DBSizeBytes,
 	}
 
 	body, err := json.Marshal(payload)
@@ -40,7 +54,7 @@ func (s *HTTPSender) Send(ctx context.Context, snap aggregate.Snapshot) error {
 
 	req, err := http.NewRequestWithContext(
 		ctx,
-		http.MethodPost,
+		http.MethodPut,
 		s.endpoint,
 		bytes.NewReader(body),
 	)
@@ -49,6 +63,7 @@ func (s *HTTPSender) Send(ctx context.Context, snap aggregate.Snapshot) error {
 	}
 
 	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", "Bearer " + s.token)
 
 	resp, err := s.client.Do(req)
 	if err != nil {

internal/sender/payload.go

@@ -9,6 +9,16 @@ type SnapshotPayload struct {
 	CPUAvg  float64 `json:"cpu_avg"`
 	MemAvg  float64 `json:"mem_avg"`
 	DiskAvg float64 `json:"disk_avg"`
-
 	Uptime  uint64  `json:"uptime"`
+
+	HostID      string `json:"host_id,omitempty"`
+	Environment string `json:"environment,omitempty"`
+
+	// Optional — only present when DB monitoring is enabled.
+	// DBDriver is a numeric identifier: 1=mysql/mariadb 2=postgres 3=redis 4=mongodb 5=sqlite
+	DBDriver         *uint8   `json:"db_driver,omitempty"`
+	DBConnPct        *float64 `json:"db_conn_pct,omitempty"`
+	DBThreadsRunning *float64 `json:"db_threads_running,omitempty"`
+	DBSlowQueries    *uint64  `json:"db_slow_queries,omitempty"`
+	DBSizeBytes      *uint64  `json:"db_size_bytes,omitempty"`
 }

package.json

@@ -0,0 +1,9 @@
+{
+	"name": "bugswatch-agent",
+	"version": "0.1.0",
+	"scripts": {
+		"release": "bun version patch && git push && git push --tags",
+		"release:minor": "bun version minor && git push && git push --tags",
+		"release:major": "bun version major && git push && git push --tags"
+	}
+}