Add new metrics

Author: panavenue

dialer.go

@@ -44,6 +44,8 @@ import (
 	"github.com/google/uuid"
 	"golang.org/x/net/proxy"
 	"google.golang.org/api/option"
+
+	tel "cloud.google.com/go/cloudsqlconn/internal/tel"
 	sqladmin "google.golang.org/api/sqladmin/v1beta4"
 )
 
@@ -71,6 +73,8 @@ var (
 	//go:embed version.txt
 	versionString string
 	userAgent     = "cloud-sql-go-connector/" + strings.TrimSpace(versionString)
+	// dialerID is a unique ID for the dialer process.
+	dialerID = uuid.New().String()
 )
 
 // keyGenerator encapsulates the details of RSA key generation to provide lazy
@@ -174,7 +178,9 @@ type Dialer struct {
 
 	// dialerID uniquely identifies a Dialer. Used for monitoring purposes,
 	// *only* when a client has configured OpenCensus exporters.
-	dialerID string
+	dialerID        string
+	metricsMu       sync.Mutex
+	metricRecorders map[instance.ConnName]tel.MetricRecorder
 
 	// dialFunc is the function used to connect to the address on the named
 	// network. By default, it is golang.org/x/net/proxy#Dial.
@@ -190,6 +196,18 @@ type Dialer struct {
 	// metadataExchangeDisabled true when the dialer should never
 	// send MDX mdx requests.
 	metadataExchangeDisabled bool
+
+	// applicationName is the name of the application using the dialer.
+	applicationName string
+
+	// disableBuiltInMetrics turns the internal metric export into a no-op.
+	disableBuiltInMetrics bool
+
+	// clientOpts are options for all Google Cloud API clients.
+	clientOpts []option.ClientOption
+
+	// userAgent is the combined user agent string.
+	userAgent string
 }
 
 var (
@@ -208,11 +226,12 @@ func (nullLogger) Debugf(_ context.Context, _ string, _ ...interface{}) {}
 // RSA keypair is generated will be faster.
 func NewDialer(ctx context.Context, opts ...Option) (*Dialer, error) {
 	cfg := &dialerConfig{
-		refreshTimeout: cloudsql.RefreshTimeout,
-		dialFunc:       proxy.Dial,
-		logger:         nullLogger{},
-		useragents:     []string{userAgent},
-		failoverPeriod: cloudsql.FailoverPeriod,
+		refreshTimeout:  cloudsql.RefreshTimeout,
+		dialFunc:        proxy.Dial,
+		logger:          nullLogger{},
+		useragents:      []string{userAgent},
+		failoverPeriod:  cloudsql.FailoverPeriod,
+		applicationName: "unknown",
 	}
 	for _, opt := range opts {
 		opt(cfg)
@@ -318,17 +337,49 @@ func NewDialer(ctx context.Context, opts ...Option) (*Dialer, error) {
 		sqladmin:                 client,
 		logger:                   cfg.logger,
 		defaultDialConfig:        dc,
-		dialerID:                 uuid.New().String(),
+		dialerID:                 dialerID,
 		iamTokenProvider:         cfg.iamLoginTokenProvider,
+		metricRecorders:          map[instance.ConnName]tel.MetricRecorder{},
 		dialFunc:                 cfg.dialFunc,
 		resolver:                 r,
 		failoverPeriod:           cfg.failoverPeriod,
 		metadataExchangeDisabled: cfg.metadataExchangeDisabled,
+		userAgent:                strings.Join(cfg.useragents, " "),
+		applicationName:          cfg.applicationName,
 	}
 
+	// print dialer id to terminal for debugging purposes
+	fmt.Println("Cloud SQL Go Connector Dialer ID:", d.dialerID)
+
 	return d, nil
 }
 
+// metricRecorder does a lazy initialization of the metric exporter.
+func (d *Dialer) metricRecorder(ctx context.Context, inst instance.ConnName) tel.MetricRecorder {
+	d.metricsMu.Lock()
+	defer d.metricsMu.Unlock()
+	if mr, ok := d.metricRecorders[inst]; ok {
+		return mr
+	}
+	cfg := tel.Config{
+		Enabled:            !d.disableBuiltInMetrics,
+		Version:            versionString,
+		ResourceContainer:  inst.Project(),
+		ResourceID:         inst.Name(),
+		ClientUID:          d.dialerID,
+		ApplicationName:    d.applicationName,
+		Region:             inst.Region(),
+		ClientRegion:       "Client-Region-Testing",    // TODO: detect client region
+		ComputePlatform:    "Compute-Platform-Testing", // TODO: detect compute platform
+		ConnectorType:      tel.ConnectorTypeValue(d.userAgent),
+		ConnectorVersion:   versionString,
+		DatabaseEngineType: "DB-Engine-Type-Testing", // TODO: detect database engine type
+	}
+	mr := tel.NewMetricRecorder(ctx, d.logger, cfg, d.clientOpts...)
+	d.metricRecorders[inst] = mr
+	return mr
+}
+
 // Dial returns a net.Conn connected to the specified Cloud SQL instance. The
 // icn argument may be the instance's connection name in the format
 // "project-name:region:instance-name" or a DNS name that resolves to an
@@ -339,8 +390,29 @@ func (d *Dialer) Dial(ctx context.Context, icn string, opts ...DialOption) (conn
 		return nil, ErrDialerClosed
 	default:
 	}
+	cfg := d.defaultDialConfig
+	for _, opt := range opts {
+		opt(&cfg)
+	}
+
+	// Resolve the instance connection name to a ConnName struct.
+	// Note: icn may be a domain name that resolves to an instance connection name.
+	cn, err := d.resolver.Resolve(ctx, icn)
+	if err != nil {
+		return nil, err
+	}
+	mr := d.metricRecorder(ctx, cn)
+
 	startTime := time.Now()
 	var endDial trace.EndSpanFunc
+	attrs := tel.Attributes{
+		IAMAuthN:    cfg.useIAMAuthN,
+		RefreshType: tel.RefreshAheadType,
+		IPType:      cfg.ipType,
+	}
+	if d.lazyRefresh {
+		attrs.RefreshType = tel.RefreshLazyType
+	}
 	ctx, endDial = trace.StartSpan(ctx, "cloud.google.com/go/cloudsqlconn.Dial",
 		trace.AddInstanceName(icn),
 		trace.AddDialerID(d.dialerID),
@@ -349,10 +421,6 @@ func (d *Dialer) Dial(ctx context.Context, icn string, opts ...DialOption) (conn
 		trace.RecordDialError(context.Background(), icn, d.dialerID, err)
 		endDial(err)
 	}()
-	cn, err := d.resolver.Resolve(ctx, icn)
-	if err != nil {
-		return nil, err
-	}
 
 	// Log if resolver changed the instance name input string.
 	if cn.DomainName() != "" {
@@ -363,14 +431,10 @@ func (d *Dialer) Dial(ctx context.Context, icn string, opts ...DialOption) (conn
 		d.logger.Debugf(ctx, "resolved instance connection string %s to %s", icn, cn.String())
 	}
 
-	cfg := d.defaultDialConfig
-	for _, opt := range opts {
-		opt(&cfg)
-	}
-
 	var endInfo trace.EndSpanFunc
 	ctx, endInfo = trace.StartSpan(ctx, "cloud.google.com/go/cloudsqlconn/internal.InstanceInfo")
-	c, err := d.connectionInfoCache(ctx, cn, &cfg.useIAMAuthN)
+	c, cacheHit, err := d.connectionInfoCache(ctx, cn, &cfg.useIAMAuthN)
+	attrs.CacheHit = cacheHit
 	if err != nil {
 		endInfo(err)
 		return nil, err
@@ -453,10 +517,16 @@ func (d *Dialer) Dial(ctx context.Context, icn string, opts ...DialOption) (conn
 	n := c.openConnsCount.Add(1)
 	trace.RecordOpenConnections(ctx, int64(n), d.dialerID, cn.String())
 	trace.RecordDialLatency(ctx, icn, d.dialerID, latency)
+	mr.RecordOpenConnection(ctx, attrs)
+	mr.RecordConnectLatencies(ctx, attrs, latency)
 
 	closeFunc := func() {
 		n := c.openConnsCount.Add(^uint64(0)) // c.openConnsCount = c.openConnsCount - 1
 		trace.RecordOpenConnections(context.Background(), int64(n), d.dialerID, cn.String())
+		mr.RecordClosedConnection(context.Background(), attrs)
+		mr.RecordClosedConnectionCount(context.Background(), attrs)
+		// lot the message to terminal for debugging purposes
+		fmt.Println("Cloud SQL Go Connector Dialer ID:", d.dialerID, "closed connection to instance:", cn.String())
 	}
 	errFunc := func(err error) {
 		// io.EOF occurs when the server closes the connection. This is safe to
@@ -553,7 +623,7 @@ func (d *Dialer) EngineVersion(ctx context.Context, icn string) (string, error)
 	if err != nil {
 		return "", err
 	}
-	c, err := d.connectionInfoCache(ctx, cn, &d.defaultDialConfig.useIAMAuthN)
+	c, _, err := d.connectionInfoCache(ctx, cn, &d.defaultDialConfig.useIAMAuthN)
 	if err != nil {
 		return "", err
 	}
@@ -577,7 +647,7 @@ func (d *Dialer) Warmup(ctx context.Context, icn string, opts ...DialOption) err
 	for _, opt := range opts {
 		opt(&cfg)
 	}
-	c, err := d.connectionInfoCache(ctx, cn, &cfg.useIAMAuthN)
+	c, _, err := d.connectionInfoCache(ctx, cn, &cfg.useIAMAuthN)
 	if err != nil {
 		return err
 	}
@@ -724,7 +794,7 @@ func createKey(cn instance.ConnName) cacheKey {
 // modify the existing one, or leave it unchanged as needed.
 func (d *Dialer) connectionInfoCache(
 	ctx context.Context, cn instance.ConnName, useIAMAuthN *bool,
-) (*monitoredCache, error) {
+) (*monitoredCache, bool, error) {
 	k := createKey(cn)
 
 	d.lock.RLock()
@@ -733,7 +803,7 @@ func (d *Dialer) connectionInfoCache(
 
 	if ok && !c.isClosed() {
 		c.UpdateRefresh(useIAMAuthN)
-		return c, nil
+		return c, ok, nil
 	}
 
 	d.lock.Lock()
@@ -745,7 +815,7 @@ func (d *Dialer) connectionInfoCache(
 	// c exists and is not closed
 	if ok && !c.isClosed() {
 		c.UpdateRefresh(useIAMAuthN)
-		return c, nil
+		return c, ok, nil
 	}
 
 	// Create a new instance of monitoredCache
@@ -756,7 +826,7 @@ func (d *Dialer) connectionInfoCache(
 	d.logger.Debugf(ctx, "[%v] Connection info added to cache", cn.String())
 	rsaKey, err := d.keyGenerator.rsaKey()
 	if err != nil {
-		return nil, err
+		return nil, ok, err
 	}
 	var cache connectionInfoCache
 	if d.lazyRefresh {
@@ -779,7 +849,7 @@ func (d *Dialer) connectionInfoCache(
 	c = newMonitoredCache(cache, cn, d.failoverPeriod, d.resolver, d.logger)
 	d.cache[k] = c
 
-	return c, nil
+	return c, ok, nil
 }
 
 // newMDXRequest builds a metadata exchange request based on the connection

go.mod

@@ -7,12 +7,17 @@ toolchain go1.25.3
 require (
 	cloud.google.com/go/auth v0.17.0
 	cloud.google.com/go/auth/oauth2adapt v0.2.8
+	github.com/GoogleCloudPlatform/opentelemetry-operations-go/exporter/metric v0.54.0
 	github.com/go-sql-driver/mysql v1.9.3
 	github.com/google/uuid v1.6.0
 	github.com/jackc/pgx/v4 v4.18.3
 	github.com/jackc/pgx/v5 v5.7.6
 	github.com/microsoft/go-mssqldb v1.9.3
 	go.opencensus.io v0.24.0
+	go.opentelemetry.io/otel v1.38.0
+	go.opentelemetry.io/otel/metric v1.38.0
+	go.opentelemetry.io/otel/sdk v1.38.0
+	go.opentelemetry.io/otel/sdk/metric v1.38.0
 	golang.org/x/net v0.46.0
 	golang.org/x/oauth2 v0.32.0
 	golang.org/x/time v0.14.0
@@ -24,7 +29,9 @@ require (
 
 require (
 	cloud.google.com/go/compute/metadata v0.9.0 // indirect
+	cloud.google.com/go/monitoring v1.24.2 // indirect
 	filippo.io/edwards25519 v1.1.0 // indirect
+	github.com/GoogleCloudPlatform/opentelemetry-operations-go/internal/resourcemapping v0.54.0 // indirect
 	github.com/felixge/httpsnoop v1.0.4 // indirect
 	github.com/go-logr/logr v1.4.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
@@ -43,12 +50,13 @@ require (
 	github.com/jackc/pgtype v1.14.4 // indirect
 	github.com/jackc/puddle/v2 v2.2.2 // indirect
 	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
+	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.63.0 // indirect
 	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.63.0 // indirect
-	go.opentelemetry.io/otel v1.38.0 // indirect
-	go.opentelemetry.io/otel/metric v1.38.0 // indirect
 	go.opentelemetry.io/otel/trace v1.38.0 // indirect
 	golang.org/x/crypto v0.43.0 // indirect
 	golang.org/x/sync v0.17.0 // indirect
 	golang.org/x/sys v0.37.0 // indirect
 	golang.org/x/text v0.30.0 // indirect
+	google.golang.org/genproto v0.0.0-20250922171735-9219d122eba9 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20250922171735-9219d122eba9 // indirect
 )