swarm: integrate OpenTracing; propagate ctx to internal APIs (#17169)

* swarm: propagate ctx, enable opentracing

* swarm/tracing: log error when tracing is misconfigured

vendor/github.com/uber/jaeger-client-go/utils/http_json.go

@@ -0,0 +1,54 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package utils
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+)
+
+// GetJSON makes an HTTP call to the specified URL and parses the returned JSON into `out`.
+func GetJSON(url string, out interface{}) error {
+	resp, err := http.Get(url)
+	if err != nil {
+		return err
+	}
+	return ReadJSON(resp, out)
+}
+
+// ReadJSON reads JSON from http.Response and parses it into `out`
+func ReadJSON(resp *http.Response, out interface{}) error {
+	defer resp.Body.Close()
+
+	if resp.StatusCode >= 400 {
+		body, err := ioutil.ReadAll(resp.Body)
+		if err != nil {
+			return err
+		}
+
+		return fmt.Errorf("StatusCode: %d, Body: %s", resp.StatusCode, body)
+	}
+
+	if out == nil {
+		io.Copy(ioutil.Discard, resp.Body)
+		return nil
+	}
+
+	decoder := json.NewDecoder(resp.Body)
+	return decoder.Decode(out)
+}

vendor/github.com/uber/jaeger-client-go/utils/localip.go

@@ -0,0 +1,84 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package utils
+
+import (
+	"errors"
+	"net"
+)
+
+// This code is borrowed from https://github.com/uber/tchannel-go/blob/dev/localip.go
+
+// scoreAddr scores how likely the given addr is to be a remote address and returns the
+// IP to use when listening. Any address which receives a negative score should not be used.
+// Scores are calculated as:
+// -1 for any unknown IP addresses.
+// +300 for IPv4 addresses
+// +100 for non-local addresses, extra +100 for "up" interaces.
+func scoreAddr(iface net.Interface, addr net.Addr) (int, net.IP) {
+	var ip net.IP
+	if netAddr, ok := addr.(*net.IPNet); ok {
+		ip = netAddr.IP
+	} else if netIP, ok := addr.(*net.IPAddr); ok {
+		ip = netIP.IP
+	} else {
+		return -1, nil
+	}
+
+	var score int
+	if ip.To4() != nil {
+		score += 300
+	}
+	if iface.Flags&net.FlagLoopback == 0 && !ip.IsLoopback() {
+		score += 100
+		if iface.Flags&net.FlagUp != 0 {
+			score += 100
+		}
+	}
+	return score, ip
+}
+
+// HostIP tries to find an IP that can be used by other machines to reach this machine.
+func HostIP() (net.IP, error) {
+	interfaces, err := net.Interfaces()
+	if err != nil {
+		return nil, err
+	}
+
+	bestScore := -1
+	var bestIP net.IP
+	// Select the highest scoring IP as the best IP.
+	for _, iface := range interfaces {
+		addrs, err := iface.Addrs()
+		if err != nil {
+			// Skip this interface if there is an error.
+			continue
+		}
+
+		for _, addr := range addrs {
+			score, ip := scoreAddr(iface, addr)
+			if score > bestScore {
+				bestScore = score
+				bestIP = ip
+			}
+		}
+	}
+
+	if bestScore == -1 {
+		return nil, errors.New("no addresses to listen on")
+	}
+
+	return bestIP, nil
+}

vendor/github.com/uber/jaeger-client-go/utils/rand.go

@@ -0,0 +1,46 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package utils
+
+import (
+	"math/rand"
+	"sync"
+)
+
+// lockedSource allows a random number generator to be used by multiple goroutines concurrently.
+// The code is very similar to math/rand.lockedSource, which is unfortunately not exposed.
+type lockedSource struct {
+	mut sync.Mutex
+	src rand.Source
+}
+
+// NewRand returns a rand.Rand that is threadsafe.
+func NewRand(seed int64) *rand.Rand {
+	return rand.New(&lockedSource{src: rand.NewSource(seed)})
+}
+
+func (r *lockedSource) Int63() (n int64) {
+	r.mut.Lock()
+	n = r.src.Int63()
+	r.mut.Unlock()
+	return
+}
+
+// Seed implements Seed() of Source
+func (r *lockedSource) Seed(seed int64) {
+	r.mut.Lock()
+	r.src.Seed(seed)
+	r.mut.Unlock()
+}

vendor/github.com/uber/jaeger-client-go/utils/rate_limiter.go

@@ -0,0 +1,77 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package utils
+
+import (
+	"sync"
+	"time"
+)
+
+// RateLimiter is a filter used to check if a message that is worth itemCost units is within the rate limits.
+type RateLimiter interface {
+	CheckCredit(itemCost float64) bool
+}
+
+type rateLimiter struct {
+	sync.Mutex
+
+	creditsPerSecond float64
+	balance          float64
+	maxBalance       float64
+	lastTick         time.Time
+
+	timeNow func() time.Time
+}
+
+// NewRateLimiter creates a new rate limiter based on leaky bucket algorithm, formulated in terms of a
+// credits balance that is replenished every time CheckCredit() method is called (tick) by the amount proportional
+// to the time elapsed since the last tick, up to max of creditsPerSecond. A call to CheckCredit() takes a cost
+// of an item we want to pay with the balance. If the balance exceeds the cost of the item, the item is "purchased"
+// and the balance reduced, indicated by returned value of true. Otherwise the balance is unchanged and return false.
+//
+// This can be used to limit a rate of messages emitted by a service by instantiating the Rate Limiter with the
+// max number of messages a service is allowed to emit per second, and calling CheckCredit(1.0) for each message
+// to determine if the message is within the rate limit.
+//
+// It can also be used to limit the rate of traffic in bytes, by setting creditsPerSecond to desired throughput
+// as bytes/second, and calling CheckCredit() with the actual message size.
+func NewRateLimiter(creditsPerSecond, maxBalance float64) RateLimiter {
+	return &rateLimiter{
+		creditsPerSecond: creditsPerSecond,
+		balance:          maxBalance,
+		maxBalance:       maxBalance,
+		lastTick:         time.Now(),
+		timeNow:          time.Now}
+}
+
+func (b *rateLimiter) CheckCredit(itemCost float64) bool {
+	b.Lock()
+	defer b.Unlock()
+	// calculate how much time passed since the last tick, and update current tick
+	currentTime := b.timeNow()
+	elapsedTime := currentTime.Sub(b.lastTick)
+	b.lastTick = currentTime
+	// calculate how much credit have we accumulated since the last tick
+	b.balance += elapsedTime.Seconds() * b.creditsPerSecond
+	if b.balance > b.maxBalance {
+		b.balance = b.maxBalance
+	}
+	// if we have enough credits to pay for current item, then reduce balance and allow
+	if b.balance >= itemCost {
+		b.balance -= itemCost
+		return true
+	}
+	return false
+}

vendor/github.com/uber/jaeger-client-go/utils/udp_client.go

@@ -0,0 +1,98 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package utils
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"net"
+
+	"github.com/uber/jaeger-client-go/thrift"
+
+	"github.com/uber/jaeger-client-go/thrift-gen/agent"
+	"github.com/uber/jaeger-client-go/thrift-gen/jaeger"
+	"github.com/uber/jaeger-client-go/thrift-gen/zipkincore"
+)
+
+// UDPPacketMaxLength is the max size of UDP packet we want to send, synced with jaeger-agent
+const UDPPacketMaxLength = 65000
+
+// AgentClientUDP is a UDP client to Jaeger agent that implements agent.Agent interface.
+type AgentClientUDP struct {
+	agent.Agent
+	io.Closer
+
+	connUDP       *net.UDPConn
+	client        *agent.AgentClient
+	maxPacketSize int                   // max size of datagram in bytes
+	thriftBuffer  *thrift.TMemoryBuffer // buffer used to calculate byte size of a span
+}
+
+// NewAgentClientUDP creates a client that sends spans to Jaeger Agent over UDP.
+func NewAgentClientUDP(hostPort string, maxPacketSize int) (*AgentClientUDP, error) {
+	if maxPacketSize == 0 {
+		maxPacketSize = UDPPacketMaxLength
+	}
+
+	thriftBuffer := thrift.NewTMemoryBufferLen(maxPacketSize)
+	protocolFactory := thrift.NewTCompactProtocolFactory()
+	client := agent.NewAgentClientFactory(thriftBuffer, protocolFactory)
+
+	destAddr, err := net.ResolveUDPAddr("udp", hostPort)
+	if err != nil {
+		return nil, err
+	}
+
+	connUDP, err := net.DialUDP(destAddr.Network(), nil, destAddr)
+	if err != nil {
+		return nil, err
+	}
+	if err := connUDP.SetWriteBuffer(maxPacketSize); err != nil {
+		return nil, err
+	}
+
+	clientUDP := &AgentClientUDP{
+		connUDP:       connUDP,
+		client:        client,
+		maxPacketSize: maxPacketSize,
+		thriftBuffer:  thriftBuffer}
+	return clientUDP, nil
+}
+
+// EmitZipkinBatch implements EmitZipkinBatch() of Agent interface
+func (a *AgentClientUDP) EmitZipkinBatch(spans []*zipkincore.Span) error {
+	return errors.New("Not implemented")
+}
+
+// EmitBatch implements EmitBatch() of Agent interface
+func (a *AgentClientUDP) EmitBatch(batch *jaeger.Batch) error {
+	a.thriftBuffer.Reset()
+	a.client.SeqId = 0 // we have no need for distinct SeqIds for our one-way UDP messages
+	if err := a.client.EmitBatch(batch); err != nil {
+		return err
+	}
+	if a.thriftBuffer.Len() > a.maxPacketSize {
+		return fmt.Errorf("Data does not fit within one UDP packet; size %d, max %d, spans %d",
+			a.thriftBuffer.Len(), a.maxPacketSize, len(batch.Spans))
+	}
+	_, err := a.connUDP.Write(a.thriftBuffer.Bytes())
+	return err
+}
+
+// Close implements Close() of io.Closer and closes the underlying UDP connection.
+func (a *AgentClientUDP) Close() error {
+	return a.connUDP.Close()
+}

vendor/github.com/uber/jaeger-client-go/utils/utils.go

@@ -0,0 +1,87 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package utils
+
+import (
+	"encoding/binary"
+	"errors"
+	"net"
+	"strconv"
+	"strings"
+	"time"
+)
+
+var (
+	// ErrEmptyIP an error for empty ip strings
+	ErrEmptyIP = errors.New("empty string given for ip")
+
+	// ErrNotHostColonPort an error for invalid host port string
+	ErrNotHostColonPort = errors.New("expecting host:port")
+
+	// ErrNotFourOctets an error for the wrong number of octets after splitting a string
+	ErrNotFourOctets = errors.New("Wrong number of octets")
+)
+
+// ParseIPToUint32 converts a string ip (e.g. "x.y.z.w") to an uint32
+func ParseIPToUint32(ip string) (uint32, error) {
+	if ip == "" {
+		return 0, ErrEmptyIP
+	}
+
+	if ip == "localhost" {
+		return 127<<24 | 1, nil
+	}
+
+	octets := strings.Split(ip, ".")
+	if len(octets) != 4 {
+		return 0, ErrNotFourOctets
+	}
+
+	var intIP uint32
+	for i := 0; i < 4; i++ {
+		octet, err := strconv.Atoi(octets[i])
+		if err != nil {
+			return 0, err
+		}
+		intIP = (intIP << 8) | uint32(octet)
+	}
+
+	return intIP, nil
+}
+
+// ParsePort converts port number from string to uin16
+func ParsePort(portString string) (uint16, error) {
+	port, err := strconv.ParseUint(portString, 10, 16)
+	return uint16(port), err
+}
+
+// PackIPAsUint32 packs an IPv4 as uint32
+func PackIPAsUint32(ip net.IP) uint32 {
+	if ipv4 := ip.To4(); ipv4 != nil {
+		return binary.BigEndian.Uint32(ipv4)
+	}
+	return 0
+}
+
+// TimeToMicrosecondsSinceEpochInt64 converts Go time.Time to a long
+// representing time since epoch in microseconds, which is used expected
+// in the Jaeger spans encoded as Thrift.
+func TimeToMicrosecondsSinceEpochInt64(t time.Time) int64 {
+	// ^^^ Passing time.Time by value is faster than passing a pointer!
+	// BenchmarkTimeByValue-8	2000000000	         1.37 ns/op
+	// BenchmarkTimeByPtr-8  	2000000000	         1.98 ns/op
+
+	return t.UnixNano() / 1000
+}