coder · mtojek · Apr 27, 2023 · Apr 24, 2023 · Apr 24, 2023 · Apr 24, 2023
diff --git a/agent/agent.go b/agent/agent.go
@@ -16,7 +16,6 @@ import (
 	"os"
 	"os/user"
 	"path/filepath"
-	"reflect"
 	"sort"
 	"strconv"
 	"strings"
@@ -1223,11 +1222,11 @@ func (a *agent) startReportingConnectionStats(ctx context.Context) {
 		// Convert from microseconds to milliseconds.
 		stats.ConnectionMedianLatencyMS /= 1000
 
-		lastStat := a.latestStat.Load()
-		if lastStat != nil && reflect.DeepEqual(lastStat, stats) {
-			a.logger.Info(ctx, "skipping stat because nothing changed")
-			return
-		}
+		// Collect agent metrics.
+		// Agent metrics are changing all the time, so there is no need to perform
+		// reflect.DeepEqual to see if stats should be transferred.
+		stats.Metrics = collectMetrics()
+
 		a.latestStat.Store(stats)
 
 		select {

diff --git a/agent/metrics.go b/agent/metrics.go
@@ -0,0 +1,52 @@
+package agent
+
+import (
+	"fmt"
+	"strings"
+
+	"tailscale.com/util/clientmetric"
+
+	"github.com/coder/coder/codersdk/agentsdk"
+)
+
+func collectMetrics() []agentsdk.AgentMetric {
+	// Tailscale metrics
+	metrics := clientmetric.Metrics()
+	collected := make([]agentsdk.AgentMetric, 0, len(metrics))
+	for _, m := range metrics {
+		if isIgnoredMetric(m.Name()) {
+			continue
+		}
+
+		collected = append(collected, agentsdk.AgentMetric{
+			Name:  m.Name(),
+			Type:  asMetricType(m.Type()),
+			Value: float64(m.Value()),
+		})
+	}
+	return collected
+}
+
+// isIgnoredMetric checks if the metric should be ignored, as Coder agent doesn't use related features.
+// Expected metric families: magicsock_*, derp_*, tstun_*, netcheck_*, portmap_*, etc.
+func isIgnoredMetric(metricName string) bool {
+	if strings.HasPrefix(metricName, "dns_") ||
+		strings.HasPrefix(metricName, "controlclient_") ||
+		strings.HasPrefix(metricName, "peerapi_") ||
+		strings.HasPrefix(metricName, "profiles_") ||
+		strings.HasPrefix(metricName, "tstun_") {
+		return true
+	}
+	return false
+}
+
+func asMetricType(typ clientmetric.Type) agentsdk.AgentMetricType {
+	switch typ {
+	case clientmetric.TypeGauge:
+		return agentsdk.AgentMetricTypeGauge
+	case clientmetric.TypeCounter:
+		return agentsdk.AgentMetricTypeCounter
+	default:
+		panic(fmt.Sprintf("unknown metric type: %d", typ))
+	}
+}
diff --git a/cli/server.go b/cli/server.go
@@ -723,6 +723,20 @@ func (r *RootCmd) Server(newAPI func(context.Context, *coderd.Options) (*coderd.
 						return xerrors.Errorf("register agent stats prometheus metric: %w", err)
 					}
 					defer closeAgentStatsFunc()
+
+					metricsAggregator, err := prometheusmetrics.NewMetricsAggregator(logger, options.PrometheusRegistry, 0)
+					if err != nil {
+						return xerrors.Errorf("can't initialize metrics aggregator: %w", err)
+					}
+
+					cancelMetricsAggregator := metricsAggregator.Run(ctx)
+					defer cancelMetricsAggregator()
+
+					options.UpdateAgentMetrics = metricsAggregator.Update
+					err = options.PrometheusRegistry.Register(metricsAggregator)
+					if err != nil {
+						return xerrors.Errorf("can't register metrics aggregator as collector: %w", err)
+					}
 				}
 
 				//nolint:revive

diff --git a/coderd/apidoc/docs.go b/coderd/apidoc/docs.go
diff --git a/coderd/apidoc/swagger.json b/coderd/apidoc/swagger.json
diff --git a/coderd/coderd.go b/coderd/coderd.go
@@ -38,6 +38,8 @@ import (
 	"cdr.dev/slog"
 
 	"github.com/coder/coder/buildinfo"
+	"github.com/coder/coder/codersdk/agentsdk"
+
 	// Used for swagger docs.
 	_ "github.com/coder/coder/coderd/apidoc"
 	"github.com/coder/coder/coderd/audit"
@@ -146,6 +148,8 @@ type Options struct {
 	SSHConfig codersdk.SSHConfigResponse
 
 	HTTPClient *http.Client
+
+	UpdateAgentMetrics func(ctx context.Context, username, workspaceName, agentName string, metrics []agentsdk.AgentMetric)
 }
 
 // @title Coder API