Update ai3/go-common

vendor/git.autistici.org/ai3/go-common/ldap/pool.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"github.com/cenkalti/backoff"
+	"go.opencensus.io/trace"
 	"gopkg.in/ldap.v2"
 )
 
@@ -147,9 +148,18 @@ func NewConnectionPool(uri, bindDN, bindPw string, cacheSize int) (*ConnectionPo
 	}, nil
 }
 
-func (p *ConnectionPool) doRequest(ctx context.Context, fn func(*ldap.Conn) error) error {
-	return backoff.Retry(func() error {
-		conn, err := p.Get(ctx)
+func (p *ConnectionPool) doRequest(ctx context.Context, name string, attrs []trace.Attribute, fn func(*ldap.Conn) error) error {
+	// Tracing: initialize a new client span.
+	sctx, span := trace.StartSpan(ctx, name,
+		trace.WithSpanKind(trace.SpanKindClient))
+	defer span.End()
+
+	if len(attrs) > 0 {
+		span.AddAttributes(attrs...)
+	}
+
+	rerr := backoff.Retry(func() error {
+		conn, err := p.Get(sctx)
 		if err != nil {
 			// Here conn is nil, so we don't need to Release it.
 			if isTemporaryLDAPError(err) {
@@ -158,7 +168,7 @@ func (p *ConnectionPool) doRequest(ctx context.Context, fn func(*ldap.Conn) erro
 			return backoff.Permanent(err)
 		}
 
-		if deadline, ok := ctx.Deadline(); ok {
+		if deadline, ok := sctx.Deadline(); ok {
 			conn.SetTimeout(time.Until(deadline))
 		}
 
@@ -169,30 +179,42 @@ func (p *ConnectionPool) doRequest(ctx context.Context, fn func(*ldap.Conn) erro
 		}
 		return err
 	}, backoff.WithContext(newExponentialBackOff(), ctx))
+
+	// Tracing: set the final status.
+	span.SetStatus(errorToTraceStatus(rerr))
+
+	return rerr
 }
 
 // Search performs the given search request. It will retry the request
 // on temporary errors.
 func (p *ConnectionPool) Search(ctx context.Context, searchRequest *ldap.SearchRequest) (*ldap.SearchResult, error) {
 	var result *ldap.SearchResult
-	err := p.doRequest(ctx, func(conn *ldap.Conn) error {
-		var err error
-		result, err = conn.Search(searchRequest)
-		return err
+	err := p.doRequest(ctx, "ldap.Search", []trace.Attribute{
+		trace.StringAttribute("ldap.base", searchRequest.BaseDN),
+		trace.StringAttribute("ldap.filter", searchRequest.Filter),
+		trace.Int64Attribute("ldap.scope", int64(searchRequest.Scope)),
+	}, func(conn *ldap.Conn) (cerr error) {
+		result, cerr = conn.Search(searchRequest)
+		return
 	})
 	return result, err
 }
 
 // Modify issues a ModifyRequest to the LDAP server.
 func (p *ConnectionPool) Modify(ctx context.Context, modifyRequest *ldap.ModifyRequest) error {
-	return p.doRequest(ctx, func(conn *ldap.Conn) error {
+	return p.doRequest(ctx, "ldap.Modify", []trace.Attribute{
+		trace.StringAttribute("ldap.dn", modifyRequest.DN),
+	}, func(conn *ldap.Conn) error {
 		return conn.Modify(modifyRequest)
 	})
 }
 
 // Add issues an AddRequest to the LDAP server.
 func (p *ConnectionPool) Add(ctx context.Context, addRequest *ldap.AddRequest) error {
-	return p.doRequest(ctx, func(conn *ldap.Conn) error {
+	return p.doRequest(ctx, "ldap.Add", []trace.Attribute{
+		trace.StringAttribute("ldap.dn", addRequest.DN),
+	}, func(conn *ldap.Conn) error {
 		return conn.Add(addRequest)
 	})
 }
@@ -219,3 +241,16 @@ func isTemporaryLDAPError(err error) bool {
 		return false
 	}
 }
+
+func errorToTraceStatus(err error) trace.Status {
+	switch err {
+	case nil:
+		return trace.Status{Code: trace.StatusCodeOK, Message: "OK"}
+	case context.Canceled:
+		return trace.Status{Code: trace.StatusCodeCancelled, Message: "CANCELED"}
+	case context.DeadlineExceeded:
+		return trace.Status{Code: trace.StatusCodeDeadlineExceeded, Message: "DEADLINE_EXCEEDED"}
+	default:
+		return trace.Status{Code: trace.StatusCodeUnknown, Message: err.Error()}
+	}
+}

vendor/git.autistici.org/ai3/go-common/tracing/tracing.go

@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
+	"strconv"
 	"sync"
 
 	openzipkin "github.com/openzipkin/zipkin-go"
@@ -31,6 +32,7 @@ const globalTracingConfigPath = "/etc/tracing/client.conf"
 
 type tracingConfig struct {
 	ReportURL string `json:"report_url"`
+	Sample    string `json:"sample"`
 }
 
 // Read the global tracing configuration file. Its location is
@@ -100,9 +102,23 @@ func initTracing(endpointAddr string) {
 
 		reporter := zipkinHTTP.NewReporter(config.ReportURL)
 		ze := zipkin.NewExporter(reporter, localEndpoint)
-
 		trace.RegisterExporter(ze)
-		trace.ApplyConfig(trace.Config{DefaultSampler: trace.AlwaysSample()})
+
+		var tc trace.Config
+		switch config.Sample {
+		case "", "always":
+			tc.DefaultSampler = trace.AlwaysSample()
+		case "never":
+			tc.DefaultSampler = trace.NeverSample()
+		default:
+			frac, err := strconv.ParseFloat(config.Sample, 64)
+			if err != nil {
+				log.Printf("warning: error in tracing configuration: sample: %v, tracing disabled", err)
+				return
+			}
+			tc.DefaultSampler = trace.ProbabilitySampler(frac)
+		}
+		trace.ApplyConfig(tc)
 
 		log.Printf("tracing enabled (report_url %s)", config.ReportURL)
 

vendor/git.autistici.org/ai3/go-common/unix/server.go

@@ -14,6 +14,7 @@ import (
 	"time"
 
 	"github.com/coreos/go-systemd/activation"
+	"github.com/prometheus/client_golang/prometheus"
 	"github.com/theckman/go-flock"
 )
 
@@ -51,7 +52,7 @@ func NewUNIXSocketServer(socketPath string, h Handler) (*SocketServer, error) {
 	// successfully. We could remove it before starting, but that
 	// would be dangerous if another instance was listening on
 	// that socket. So we wrap socket access with a file lock.
-	lock := flock.NewFlock(socketPath + ".lock")
+	lock := flock.New(socketPath + ".lock")
 	locked, err := lock.TryLock()
 	if err != nil {
 		return nil, err
@@ -66,7 +67,7 @@ func NewUNIXSocketServer(socketPath string, h Handler) (*SocketServer, error) {
 	}
 
 	// Always try to unlink the socket before creating it.
-	os.Remove(socketPath)
+	os.Remove(socketPath) // nolint
 
 	l, err := net.ListenUnix("unix", addr)
 	if err != nil {
@@ -98,10 +99,10 @@ func NewSystemdSocketServer(h Handler) (*SocketServer, error) {
 // Waits for active connections to terminate before returning.
 func (s *SocketServer) Close() {
 	s.closing.Store(true)
-	s.l.Close()
+	s.l.Close() // nolint
 	s.wg.Wait()
 	if s.lock != nil {
-		s.lock.Unlock()
+		s.lock.Unlock() // nolint
 	}
 }
 
@@ -122,7 +123,7 @@ func (s *SocketServer) Serve() error {
 		s.wg.Add(1)
 		go func() {
 			s.handler.ServeConnection(conn)
-			conn.Close()
+			conn.Close() // nolint
 			s.wg.Done()
 		}()
 	}
@@ -198,11 +199,15 @@ func (w *lrWriter) WriteLineCRLF(data []byte) error {
 	return w.Writer.Flush()
 }
 
+// ServeConnection handles a new connection. It will accept multiple
+// requests on the same connection (or not, depending on the client
+// preference).
 func (l *LineServer) ServeConnection(nc net.Conn) {
+	totalConnections.Inc()
 	c := textproto.NewConn(nc)
 	rw := &lrWriter{bufio.NewWriter(nc)}
 	for {
-		nc.SetReadDeadline(time.Now().Add(l.IdleTimeout))
+		nc.SetReadDeadline(time.Now().Add(l.IdleTimeout)) // nolint
 		line, err := c.ReadLineBytes()
 		if err == io.EOF {
 			break
@@ -215,17 +220,59 @@ func (l *LineServer) ServeConnection(nc net.Conn) {
 		// handler with it.  Set a write deadline on the
 		// connection to allow the full RequestTimeout time to
 		// generate the response.
-		nc.SetWriteDeadline(time.Now().Add(l.RequestTimeout + l.WriteTimeout))
+		start := time.Now()
+		nc.SetWriteDeadline(start.Add(l.RequestTimeout + l.WriteTimeout)) // nolint
 		ctx, cancel := context.WithTimeout(context.Background(), l.RequestTimeout)
 		err = l.handler.ServeLine(ctx, rw, line)
+		elapsedMs := time.Since(start).Nanoseconds() / 1000000
+		requestLatencyHist.Observe(float64(elapsedMs))
 		cancel()
 
 		// Close the connection on error, or on empty response.
 		if err != nil {
+			totalRequests.With(prometheus.Labels{
+				"status": "error",
+			}).Inc()
 			if err != ErrCloseConnection {
 				log.Printf("request error: %v", err)
 			}
 			break
 		}
+		totalRequests.With(prometheus.Labels{
+			"status": "ok",
+		}).Inc()
 	}
 }
+
+// Instrumentation metrics.
+var (
+	totalConnections = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "unix_connections_total",
+			Help: "Total number of connections.",
+		},
+	)
+	totalRequests = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "unix_requests_total",
+			Help: "Total number of requests.",
+		},
+		[]string{"status"},
+	)
+	// Histogram buckets are tuned for the low-milliseconds range
+	// (the largest bucket sits at ~1s).
+	requestLatencyHist = prometheus.NewHistogram(
+		prometheus.HistogramOpts{
+			Name:    "unix_requests_latency_ms",
+			Help:    "Latency of requests.",
+			Buckets: prometheus.ExponentialBuckets(5, 1.4142, 16),
+		},
+	)
+)
+
+func init() {
+	prometheus.MustRegister(totalConnections)
+	prometheus.MustRegister(totalRequests)
+	prometheus.MustRegister(requestLatencyHist)
+
+}

vendor/vendor.json

@@ -5,38 +5,38 @@
 		{
 			"checksumSHA1": "pLvPnUablirQucyALgrso9hLG4E=",
 			"path": "git.autistici.org/ai3/go-common",
-			"revision": "1f95fcdd58ebf63d338f05ceae29d2de811a2d2f",
-			"revisionTime": "2018-11-18T16:11:30Z"
+			"revision": "438dda6c699e73e612d0b16143076998d77c03ac",
+			"revisionTime": "2018-11-22T23:09:18Z"
 		},
 		{
 			"checksumSHA1": "1ChQcW9Biu/AgiKjsbJFg/+WhjQ=",
 			"path": "git.autistici.org/ai3/go-common/clientutil",
-			"revision": "1f95fcdd58ebf63d338f05ceae29d2de811a2d2f",
-			"revisionTime": "2018-11-18T16:11:30Z"
+			"revision": "438dda6c699e73e612d0b16143076998d77c03ac",
+			"revisionTime": "2018-11-22T23:09:18Z"
 		},
 		{
-			"checksumSHA1": "kQbBWZqrXc95wodlrOKEshQVaBo=",
+			"checksumSHA1": "npDdYYmInhdVxcCpOQ844cVlfzQ=",
 			"path": "git.autistici.org/ai3/go-common/ldap",
-			"revision": "1f95fcdd58ebf63d338f05ceae29d2de811a2d2f",
-			"revisionTime": "2018-11-18T16:11:30Z"
+			"revision": "438dda6c699e73e612d0b16143076998d77c03ac",
+			"revisionTime": "2018-11-22T23:09:18Z"
 		},
 		{
 			"checksumSHA1": "mfFIqmwojDqQdJvjLI3y7YCQ+2c=",
 			"path": "git.autistici.org/ai3/go-common/pwhash",
-			"revision": "1f95fcdd58ebf63d338f05ceae29d2de811a2d2f",
-			"revisionTime": "2018-11-18T16:11:30Z"
+			"revision": "438dda6c699e73e612d0b16143076998d77c03ac",
+			"revisionTime": "2018-11-22T23:09:18Z"
 		},
 		{
-			"checksumSHA1": "WvuSF0pz3rk7bu+5g9lqTqq97Ow=",
+			"checksumSHA1": "tWzCSEieYFl5VnKhFTosgveO6Ys=",
 			"path": "git.autistici.org/ai3/go-common/tracing",
-			"revision": "1f95fcdd58ebf63d338f05ceae29d2de811a2d2f",
-			"revisionTime": "2018-11-18T16:11:30Z"
+			"revision": "438dda6c699e73e612d0b16143076998d77c03ac",
+			"revisionTime": "2018-11-22T23:09:18Z"
 		},
 		{
-			"checksumSHA1": "Okvoje2tgehkMo1N9Q601JPgGoE=",
+			"checksumSHA1": "R18oCPkWjuPqDxPgKvG1KhiSJns=",
 			"path": "git.autistici.org/ai3/go-common/unix",
-			"revision": "1f95fcdd58ebf63d338f05ceae29d2de811a2d2f",
-			"revisionTime": "2018-11-18T16:11:30Z"
+			"revision": "438dda6c699e73e612d0b16143076998d77c03ac",
+			"revisionTime": "2018-11-22T23:09:18Z"
 		},
 		{
 			"checksumSHA1": "NtTOmajRf6xh0mkVSm18L70ncl0=",