Upgrade go-common (add tracing)

vendor/git.autistici.org/ai3/go-common/clientutil/transport.go

@@ -7,6 +7,8 @@ import (
 	"net/http"
 	"sync"
 	"time"
+
+	"git.autistici.org/ai3/go-common/tracing"
 )
 
 // The transportCache is just a cache of http transports, each
@@ -29,12 +31,12 @@ func newTransportCache(tlsConfig *tls.Config) *transportCache {
 }
 
 func (m *transportCache) newTransport(addr string) http.RoundTripper {
-	return &http.Transport{
+	return tracing.WrapTransport(&http.Transport{
 		TLSClientConfig: m.tlsConfig,
 		DialContext: func(ctx context.Context, network, _ string) (net.Conn, error) {
 			return netDialContext(ctx, network, addr)
 		},
-	}
+	})
 }
 
 func (m *transportCache) getTransport(addr string) http.RoundTripper {

vendor/git.autistici.org/ai3/go-common/serverutil/http.go

@@ -3,16 +3,18 @@ package serverutil
 import (
 	"context"
 	"crypto/tls"
+	"fmt"
 	"io"
 	"log"
 	"net"
 	"net/http"
-	"net/http/pprof"
+	_ "net/http/pprof"
 	"os"
 	"os/signal"
 	"syscall"
 	"time"
 
+	"git.autistici.org/ai3/go-common/tracing"
 	"github.com/coreos/go-systemd/daemon"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
@@ -77,6 +79,10 @@ func (config *ServerConfig) buildHTTPServer(h http.Handler) (*http.Server, error
 // the listener, otherwise it will handle graceful termination on
 // SIGINT or SIGTERM and return nil.
 func Serve(h http.Handler, config *ServerConfig, addr string) error {
+	// Wrap with tracing handler (exclude metrics and other
+	// debugging endpoints).
+	h = tracing.WrapHandler(h, guessEndpointName(addr))
+
 	// Create the HTTP server.
 	srv, err := config.buildHTTPServer(h)
 	if err != nil {
@@ -139,8 +145,10 @@ func defaultHandler(h http.Handler) http.Handler {
 	// Add an endpoint to serve Prometheus metrics.
 	root.Handle("/metrics", promhttp.Handler())
 
-	// Add the net/http/pprof debug handlers.
-	root.Handle("/debug/pprof/", pprof.Handler(""))
+	// Let the default net/http handler deal with /debug/
+	// URLs. Packages such as net/http/pprof register their
+	// handlers there in ways that aren't reproducible.
+	root.Handle("/debug/", http.DefaultServeMux)
 
 	// Forward everything else to the main handler, adding
 	// Prometheus instrumentation (requests to /metrics and
@@ -151,6 +159,18 @@ func defaultHandler(h http.Handler) http.Handler {
 	return root
 }
 
+func guessEndpointName(addr string) string {
+	_, port, err := net.SplitHostPort(addr)
+	if err != nil {
+		return addr
+	}
+	host, err := os.Hostname()
+	if err != nil {
+		return addr
+	}
+	return fmt.Sprintf("%s:%s", host, port)
+}
+
 // HTTP-related metrics.
 var (
 	// Since we instrument the root HTTP handler, we don't really

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

+package tracing
+
+import (
+	"encoding/json"
+	"errors"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+	"path/filepath"
+	"sync"
+
+	openzipkin "github.com/openzipkin/zipkin-go"
+	zipkinHTTP "github.com/openzipkin/zipkin-go/reporter/http"
+	"go.opencensus.io/exporter/zipkin"
+	"go.opencensus.io/plugin/ochttp"
+	"go.opencensus.io/trace"
+)
+
+var (
+	// Enabled reports whether tracing is globally enabled or not.
+	Enabled bool
+
+	// The active tracing configuration, if Enabled is true.
+	config tracingConfig
+
+	initOnce sync.Once
+)
+
+const globalTracingConfigPath = "/etc/tracing/client.conf"
+
+type tracingConfig struct {
+	ReportURL string `json:"report_url"`
+}
+
+// Read the global tracing configuration file. Its location is
+// hardcoded, but it can be overriden using the TRACING_CONFIG
+// environment variable.
+func readTracingConfig() error {
+	// Read and decode configuration.
+	cfgPath := globalTracingConfigPath
+	if s := os.Getenv("TRACING_CONFIG"); s != "" {
+		cfgPath = s
+	}
+	data, err := ioutil.ReadFile(cfgPath)
+	if err != nil {
+		return err
+	}
+
+	if err := json.Unmarshal(data, &config); err != nil {
+		log.Printf("warning: error in tracing configuration: %v, tracing disabled", err)
+		return err
+	}
+
+	if config.ReportURL == "" {
+		log.Printf("warning: tracing configuration contains no report_url, tracing disabled")
+		return errors.New("no report_url")
+	}
+
+	return nil
+}
+
+// Compute the service name for Zipkin: this is usually the program
+// name (without path), but it can be overriden by the TRACING_SERVICE
+// environment variable.
+func getServiceName() string {
+	if s := os.Getenv("TRACING_SERVICE"); s != "" {
+		return s
+	}
+	return filepath.Base(os.Args[0])
+}
+
+// Initialize tracing. Tracing will be enabled if the system-wide
+// tracing configuration file is present and valid. Explicitly set
+// TRACING_ENABLE=0 in the environment to disable tracing.
+//
+// We need to check the configuration as soon as possible, because
+// it's likely that client transports are created before HTTP servers,
+// and we need to wrap them with opencensus at creation time.
+func init() {
+	// Kill switch from environment.
+	if s := os.Getenv("TRACING_ENABLE"); s == "0" {
+		return
+	}
+
+	if err := readTracingConfig(); err != nil {
+		return
+	}
+
+	Enabled = true
+}
+
+func initTracing(endpointAddr string) {
+	initOnce.Do(func() {
+		localEndpoint, err := openzipkin.NewEndpoint(getServiceName(), endpointAddr)
+		if err != nil {
+			log.Printf("warning: error creating tracing endpoint: %v, tracing disabled", err)
+			return
+		}
+
+		reporter := zipkinHTTP.NewReporter(config.ReportURL)
+		ze := zipkin.NewExporter(reporter, localEndpoint)
+
+		trace.RegisterExporter(ze)
+		trace.ApplyConfig(trace.Config{DefaultSampler: trace.AlwaysSample()})
+
+		log.Printf("tracing enabled (report_url %s)", config.ReportURL)
+
+		Enabled = true
+	})
+}
+
+// WrapTransport optionally wraps a http.RoundTripper with OpenCensus
+// tracing functionality, if it is globally enabled.
+func WrapTransport(t http.RoundTripper) http.RoundTripper {
+	if Enabled {
+		t = &ochttp.Transport{Base: t}
+	}
+	return t
+}
+
+// WrapHandler wraps a http.Handler with OpenCensus tracing
+// functionality, if globally enabled.
+func WrapHandler(h http.Handler, endpointAddr string) http.Handler {
+	if Enabled {
+		initTracing(endpointAddr)
+		h = &ochttp.Handler{Handler: h}
+	}
+	return h
+}

vendor/github.com/openzipkin/zipkin-go/Makefile

+
+.DEFAULT_GOAL := test
+
+.PHONY: test
+test:
+	go test -v -race -cover ./...
+
+.PHONY: bench
+bench:
+	go test -v -run - -bench . -benchmem ./...
+
+.PHONY: protoc
+protoc:
+	protoc --go_out=. proto/v2/zipkin.proto
+
+.PHONY: lint
+lint:
+	# Ignore grep's exit code since no match returns 1.
+	-if [[ ! $TRAVIS_GO_VERSION = 1.8* ]]; then echo 'linting...' ; golint ./... ; fi
+
+.PHONY: vet
+vet:
+	go vet ./...
+
+.PHONY: all
+all: vet lint test bench
+
+.PHONY: example

vendor/github.com/openzipkin/zipkin-go/README.md

+# Zipkin Library for Go
+
+[![Travis CI](https://travis-ci.org/openzipkin/zipkin-go.svg?branch=master)](https://travis-ci.org/openzipkin/zipkin-go)
+[![CircleCI](https://circleci.com/gh/openzipkin/zipkin-go.svg?style=shield)](https://circleci.com/gh/openzipkin/zipkin-go)
+[![Appveyor CI](https://ci.appveyor.com/api/projects/status/1d0e5k96g10ajl63/branch/master?svg=true)](https://ci.appveyor.com/project/basvanbeek/zipkin-go)
+[![Coverage Status](https://img.shields.io/coveralls/github/openzipkin/zipkin-go.svg)](https://coveralls.io/github/openzipkin/zipkin-go?branch=master)
+[![Go Report Card](https://goreportcard.com/badge/github.com/openzipkin/zipkin-go)](https://goreportcard.com/report/github.com/openzipkin/zipkin-go)
+[![GoDoc](https://godoc.org/github.com/openzipkin/zipkin-go?status.svg)](https://godoc.org/github.com/openzipkin/zipkin-go)
+[![Gitter chat](https://badges.gitter.im/openzipkin/zipkin.svg)](https://gitter.im/openzipkin/zipkin?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+[![Sourcegraph](https://sourcegraph.com/github.com/openzipkin/zipkin-go/-/badge.svg)](https://sourcegraph.com/github.com/openzipkin/zipkin-go?badge)
+
+Zipkin Go is the official Go Tracer implementation for Zipkin, supported by the
+OpenZipkin community.
+
+## package organization
+`zipkin-go` is built with interoperability in mind within the OpenZipkin
+community and even 3rd parties, the library consists of several packages.
+
+The main tracing implementation can be found in the root folder of this
+repository. Reusable parts not considered core implementation or deemed
+beneficiary for usage by others are placed in their own packages within this
+repository.
+
+### model
+This library implements the Zipkin V2 Span Model which is available in the model
+package. It contains a Go data model compatible with the Zipkin V2 API and can
+automatically sanitize, parse and (de)serialize to and from the required JSON
+representation as used by the official Zipkin V2 Collectors.
+
+### propagation
+The propagation package and B3 subpackage hold the logic for propagating
+SpanContext (span identifiers and sampling flags) between services participating
+in traces. Currently Zipkin B3 Propagation is supported for HTTP and GRPC.
+
+### middleware
+The middleware subpackages contain officially supported middleware handlers and
+tracing wrappers.
+
+#### http
+An easy to use http.Handler middleware for tracing server side requests is
+provided. This allows one to use this middleware in applications using
+standard library servers as well as most available higher level frameworks. Some
+frameworks will have their own instrumentation and middleware that maps better
+for their ecosystem.
+
+For HTTP client operations `NewTransport` can return a `http.RoundTripper`
+implementation that can either wrap the standard http.Client's Transport or a
+custom provided one and add per request tracing. Since HTTP Requests can have
+one or multiple redirects it is advisable to always enclose HTTP Client calls
+with a `Span` either around the `*http.Client` call level or parent function
+level.
+
+For convenience `NewClient` is provided which returns a HTTP Client which embeds
+`*http.Client` and provides an `application span` around the HTTP calls when
+calling the `DoWithAppSpan()` method.
+
+#### grpc
+gRPC middleware / interceptors are planned for the near future.
+
+### reporter
+The reporter package holds the interface which the various Reporter
+implementations use. It is exported into its own package as it can be used by
+3rd parties to use these Reporter packages in their own libraries for exporting
+to the Zipkin ecosystem. The `zipkin-go` tracer also uses the interface to
+accept 3rd party Reporter implementations.
+
+#### HTTP Reporter
+Most common Reporter type used by Zipkin users transporting Spans to the Zipkin
+server using JSON over HTTP. The reporter holds a buffer and reports to the
+backend asynchronously.
+
+#### Kafka Reporter
+High performance Reporter transporting Spans to the Zipkin server using a Kafka
+Producer digesting JSON V2 Spans. The reporter uses the
+[Sarama async producer](https://godoc.org/github.com/Shopify/sarama#AsyncProducer)
+underneath.
+
+## usage and examples
+[HTTP Server Example](example_httpserver_test.go)

vendor/github.com/openzipkin/zipkin-go/appveyor.yml

+version: v1.0.0.{build}
+
+platform: x64
+
+clone_folder: c:\gopath\src\github.com\openzipkin\zipkin-go
+
+environment:
+  GOPATH: c:\gopath
+
+install:
+  - echo %PATH%
+  - echo %GOPATH%
+  - set PATH=%GOPATH%\bin;c:\go\bin;%PATH%
+  - go version
+  - go env
+
+build_script:
+  - go get -t -v ./...
+  - go vet ./...
+  - go test -v -race -cover ./...
+  - go test -v -run - -bench . -benchmem ./...

vendor/github.com/openzipkin/zipkin-go/circle.yml

+version: 2
+jobs:
+  build:
+    working_directory: /go/src/github.com/openzipkin/zipkin-go
+    parallelism: 1
+    docker:
+      - image: circleci/golang
+    steps:
+      - checkout
+      - run: go get -t -v -d ./...
+      - run: make vet test bench

vendor/github.com/openzipkin/zipkin-go/context.go

+package zipkin
+
+import (
+	"context"
+)
+
+// SpanFromContext retrieves a Zipkin Span from Go's context propagation
+// mechanism if found. If not found, returns nil.
+func SpanFromContext(ctx context.Context) Span {
+	if s, ok := ctx.Value(spanKey).(Span); ok {
+		return s
+	}
+	return nil
+}
+
+// NewContext stores a Zipkin Span into Go's context propagation mechanism.
+func NewContext(ctx context.Context, s Span) context.Context {
+	return context.WithValue(ctx, spanKey, s)
+}
+
+type ctxKey struct{}
+
+var spanKey = ctxKey{}

vendor/github.com/openzipkin/zipkin-go/doc.go

+/*
+Package zipkin implements a native Zipkin instrumentation library for Go.
+
+See https://zipkin.io for more information about Zipkin.
+*/
+package zipkin

vendor/github.com/openzipkin/zipkin-go/endpoint.go

+package zipkin
+
+import (
+	"net"
+	"strconv"
+	"strings"
+
+	"github.com/openzipkin/zipkin-go/model"
+)
+
+// NewEndpoint creates a new endpoint given the provided serviceName and
+// hostPort.
+func NewEndpoint(serviceName string, hostPort string) (*model.Endpoint, error) {
+	e := &model.Endpoint{
+		ServiceName: serviceName,
+	}
+
+	if hostPort == "" || hostPort == ":0" {
+		if serviceName == "" {
+			// if all properties are empty we should not have an Endpoint object.
+			return nil, nil
+		}
+		return e, nil
+	}
+
+	if strings.IndexByte(hostPort, ':') < 0 {
+		hostPort += ":0"
+	}
+
+	host, port, err := net.SplitHostPort(hostPort)
+	if err != nil {
+		return nil, err
+	}
+
+	p, err := strconv.ParseUint(port, 10, 16)
+	if err != nil {
+		return nil, err
+	}
+	e.Port = uint16(p)
+
+	addrs, err := net.LookupIP(host)
+	if err != nil {
+		return nil, err
+	}
+
+	for i := range addrs {
+		addr := addrs[i].To4()
+		if addr == nil {
+			// IPv6 - 16 bytes
+			if e.IPv6 == nil {
+				e.IPv6 = addrs[i].To16()
+			}
+		} else {
+			// IPv4 - 4 bytes
+			if e.IPv4 == nil {
+				e.IPv4 = addr
+			}
+		}
+		if e.IPv4 != nil && e.IPv6 != nil {
+			// Both IPv4 & IPv6 have been set, done...
+			break
+		}
+	}
+
+	return e, nil
+}

vendor/github.com/openzipkin/zipkin-go/idgenerator/idgenerator.go

+/*
+Package idgenerator contains several Span and Trace ID generators which can be
+used by the Zipkin tracer. Additional third party generators can be plugged in
+if they adhere to the IDGenerator interface.
+*/
+package idgenerator
+
+import (
+	"math/rand"
+	"sync"
+	"time"
+
+	"github.com/openzipkin/zipkin-go/model"
+)
+
+var (
+	seededIDGen = rand.New(rand.NewSource(time.Now().UnixNano()))
+	// NewSource returns a new pseudo-random Source seeded with the given value.
+	// Unlike the default Source used by top-level functions, this source is not
+	// safe for concurrent use by multiple goroutines. Hence the need for a mutex.
+	seededIDLock sync.Mutex
+)
+
+// IDGenerator interface can be used to provide the Zipkin Tracer with custom
+// implementations to generate Span and Trace IDs.
+type IDGenerator interface {
+	SpanID(traceID model.TraceID) model.ID // Generates a new Span ID
+	TraceID() model.TraceID                // Generates a new Trace ID
+}
+
+// NewRandom64 returns an ID Generator which can generate 64 bit trace and span
+// id's
+func NewRandom64() IDGenerator {
+	return &randomID64{}
+}
+
+// NewRandom128 returns an ID Generator which can generate 128 bit trace and 64
+// bit span id's
+func NewRandom128() IDGenerator {
+	return &randomID128{}
+}
+
+// NewRandomTimestamped generates 128 bit time sortable traceid's and 64 bit
+// spanid's.
+func NewRandomTimestamped() IDGenerator {
+	return &randomTimestamped{}
+}
+
+// randomID64 can generate 64 bit traceid's and 64 bit spanid's.
+type randomID64 struct{}
+
+func (r *randomID64) TraceID() (id model.TraceID) {
+	seededIDLock.Lock()
+	id = model.TraceID{
+		Low: uint64(seededIDGen.Int63()),
+	}
+	seededIDLock.Unlock()
+	return
+}
+
+func (r *randomID64) SpanID(traceID model.TraceID) (id model.ID) {
+	if !traceID.Empty() {
+		return model.ID(traceID.Low)
+	}
+	seededIDLock.Lock()
+	id = model.ID(seededIDGen.Int63())
+	seededIDLock.Unlock()
+	return
+}
+
+// randomID128 can generate 128 bit traceid's and 64 bit spanid's.
+type randomID128 struct{}
+
+func (r *randomID128) TraceID() (id model.TraceID) {
+	seededIDLock.Lock()
+	id = model.TraceID{
+		High: uint64(seededIDGen.Int63()),
+		Low:  uint64(seededIDGen.Int63()),
+	}
+	seededIDLock.Unlock()
+	return
+}
+
+func (r *randomID128) SpanID(traceID model.TraceID) (id model.ID) {
+	if !traceID.Empty() {
+		return model.ID(traceID.Low)
+	}
+	seededIDLock.Lock()
+	id = model.ID(seededIDGen.Int63())
+	seededIDLock.Unlock()
+	return
+}
+
+// randomTimestamped can generate 128 bit time sortable traceid's compatible
+// with AWS X-Ray and 64 bit spanid's.
+type randomTimestamped struct{}
+
+func (t *randomTimestamped) TraceID() (id model.TraceID) {
+	seededIDLock.Lock()
+	id = model.TraceID{
+		High: uint64(time.Now().Unix()<<32) + uint64(seededIDGen.Int31()),
+		Low:  uint64(seededIDGen.Int63()),
+	}
+	seededIDLock.Unlock()
+	return
+}
+
+func (t *randomTimestamped) SpanID(traceID model.TraceID) (id model.ID) {
+	if !traceID.Empty() {
+		return model.ID(traceID.Low)
+	}
+	seededIDLock.Lock()
+	id = model.ID(seededIDGen.Int63())
+	seededIDLock.Unlock()
+	return
+}

vendor/github.com/openzipkin/zipkin-go/model/annotation.go

+package model
+
+import (
+	"encoding/json"
+	"errors"
+	"time"
+)
+
+// ErrValidTimestampRequired error
+var ErrValidTimestampRequired = errors.New("valid annotation timestamp required")
+
+// Annotation associates an event that explains latency with a timestamp.
+type Annotation struct {
+	Timestamp time.Time
+	Value     string
+}
+
+// MarshalJSON implements custom JSON encoding
+func (a *Annotation) MarshalJSON() ([]byte, error) {
+	return json.Marshal(&struct {
+		Timestamp int64  `js