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Added support for Haystack tracing

This commit is contained in:
Alex Antonov 2019-05-08 17:14:04 -05:00 committed by Traefiker Bot
parent 681892148e
commit 9cf6827ccc
274 changed files with 38070 additions and 13436 deletions

View file

@ -1,6 +1,6 @@
/*
*
* Copyright 2017 gRPC authors.
* Copyright 2018 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
@ -21,10 +21,10 @@
package dns
import (
"context"
"encoding/json"
"errors"
"fmt"
"math/rand"
"net"
"os"
"strconv"
@ -32,8 +32,9 @@ import (
"sync"
"time"
"golang.org/x/net/context"
"google.golang.org/grpc/grpclog"
"google.golang.org/grpc/internal/backoff"
"google.golang.org/grpc/internal/grpcrand"
"google.golang.org/grpc/resolver"
)
@ -42,32 +43,65 @@ func init() {
}
const (
defaultPort = "443"
defaultFreq = time.Minute * 30
golang = "GO"
defaultPort = "443"
defaultFreq = time.Minute * 30
defaultDNSSvrPort = "53"
golang = "GO"
// txtPrefix is the prefix string to be prepended to the host name for txt record lookup.
txtPrefix = "_grpc_config."
// In DNS, service config is encoded in a TXT record via the mechanism
// described in RFC-1464 using the attribute name grpc_config.
txtAttribute = "grpc_config="
)
var (
errMissingAddr = errors.New("missing address")
randomGen = rand.New(rand.NewSource(time.Now().UnixNano()))
errMissingAddr = errors.New("dns resolver: missing address")
// Addresses ending with a colon that is supposed to be the separator
// between host and port is not allowed. E.g. "::" is a valid address as
// it is an IPv6 address (host only) and "[::]:" is invalid as it ends with
// a colon as the host and port separator
errEndsWithColon = errors.New("dns resolver: missing port after port-separator colon")
)
var (
defaultResolver netResolver = net.DefaultResolver
)
var customAuthorityDialler = func(authority string) func(ctx context.Context, network, address string) (net.Conn, error) {
return func(ctx context.Context, network, address string) (net.Conn, error) {
var dialer net.Dialer
return dialer.DialContext(ctx, network, authority)
}
}
var customAuthorityResolver = func(authority string) (netResolver, error) {
host, port, err := parseTarget(authority, defaultDNSSvrPort)
if err != nil {
return nil, err
}
authorityWithPort := net.JoinHostPort(host, port)
return &net.Resolver{
PreferGo: true,
Dial: customAuthorityDialler(authorityWithPort),
}, nil
}
// NewBuilder creates a dnsBuilder which is used to factory DNS resolvers.
func NewBuilder() resolver.Builder {
return &dnsBuilder{freq: defaultFreq}
return &dnsBuilder{minFreq: defaultFreq}
}
type dnsBuilder struct {
// frequency of polling the DNS server.
freq time.Duration
// minimum frequency of polling the DNS server.
minFreq time.Duration
}
// Build creates and starts a DNS resolver that watches the name resolution of the target.
func (b *dnsBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOption) (resolver.Resolver, error) {
host, port, err := parseTarget(target.Endpoint)
host, port, err := parseTarget(target.Endpoint, defaultPort)
if err != nil {
return nil, err
}
@ -90,7 +124,8 @@ func (b *dnsBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts
// DNS address (non-IP).
ctx, cancel := context.WithCancel(context.Background())
d := &dnsResolver{
freq: b.freq,
freq: b.minFreq,
backoff: backoff.Exponential{MaxDelay: b.minFreq},
host: host,
port: port,
ctx: ctx,
@ -101,6 +136,15 @@ func (b *dnsBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts
disableServiceConfig: opts.DisableServiceConfig,
}
if target.Authority == "" {
d.resolver = defaultResolver
} else {
d.resolver, err = customAuthorityResolver(target.Authority)
if err != nil {
return nil, err
}
}
d.wg.Add(1)
go d.watcher()
return d, nil
@ -111,6 +155,12 @@ func (b *dnsBuilder) Scheme() string {
return "dns"
}
type netResolver interface {
LookupHost(ctx context.Context, host string) (addrs []string, err error)
LookupSRV(ctx context.Context, service, proto, name string) (cname string, addrs []*net.SRV, err error)
LookupTXT(ctx context.Context, name string) (txts []string, err error)
}
// ipResolver watches for the name resolution update for an IP address.
type ipResolver struct {
cc resolver.ClientConn
@ -146,12 +196,15 @@ func (i *ipResolver) watcher() {
// dnsResolver watches for the name resolution update for a non-IP target.
type dnsResolver struct {
freq time.Duration
host string
port string
ctx context.Context
cancel context.CancelFunc
cc resolver.ClientConn
freq time.Duration
backoff backoff.Exponential
retryCount int
host string
port string
resolver netResolver
ctx context.Context
cancel context.CancelFunc
cc resolver.ClientConn
// rn channel is used by ResolveNow() to force an immediate resolution of the target.
rn chan struct{}
t *time.Timer
@ -190,8 +243,15 @@ func (d *dnsResolver) watcher() {
case <-d.rn:
}
result, sc := d.lookup()
// Next lookup should happen after an interval defined by d.freq.
d.t.Reset(d.freq)
// Next lookup should happen within an interval defined by d.freq. It may be
// more often due to exponential retry on empty address list.
if len(result) == 0 {
d.retryCount++
d.t.Reset(d.backoff.Backoff(d.retryCount))
} else {
d.retryCount = 0
d.t.Reset(d.freq)
}
d.cc.NewServiceConfig(sc)
d.cc.NewAddress(result)
}
@ -199,13 +259,13 @@ func (d *dnsResolver) watcher() {
func (d *dnsResolver) lookupSRV() []resolver.Address {
var newAddrs []resolver.Address
_, srvs, err := lookupSRV(d.ctx, "grpclb", "tcp", d.host)
_, srvs, err := d.resolver.LookupSRV(d.ctx, "grpclb", "tcp", d.host)
if err != nil {
grpclog.Infof("grpc: failed dns SRV record lookup due to %v.\n", err)
return nil
}
for _, s := range srvs {
lbAddrs, err := lookupHost(d.ctx, s.Target)
lbAddrs, err := d.resolver.LookupHost(d.ctx, s.Target)
if err != nil {
grpclog.Infof("grpc: failed load balancer address dns lookup due to %v.\n", err)
continue
@ -224,7 +284,7 @@ func (d *dnsResolver) lookupSRV() []resolver.Address {
}
func (d *dnsResolver) lookupTXT() string {
ss, err := lookupTXT(d.ctx, d.host)
ss, err := d.resolver.LookupTXT(d.ctx, txtPrefix+d.host)
if err != nil {
grpclog.Infof("grpc: failed dns TXT record lookup due to %v.\n", err)
return ""
@ -244,7 +304,7 @@ func (d *dnsResolver) lookupTXT() string {
func (d *dnsResolver) lookupHost() []resolver.Address {
var newAddrs []resolver.Address
addrs, err := lookupHost(d.ctx, d.host)
addrs, err := d.resolver.LookupHost(d.ctx, d.host)
if err != nil {
grpclog.Warningf("grpc: failed dns A record lookup due to %v.\n", err)
return nil
@ -286,17 +346,16 @@ func formatIP(addr string) (addrIP string, ok bool) {
return "[" + addr + "]", true
}
// parseTarget takes the user input target string, returns formatted host and port info.
// parseTarget takes the user input target string and default port, returns formatted host and port info.
// If target doesn't specify a port, set the port to be the defaultPort.
// If target is in IPv6 format and host-name is enclosed in sqarue brackets, brackets
// are strippd when setting the host.
// If target is in IPv6 format and host-name is enclosed in square brackets, brackets
// are stripped when setting the host.
// examples:
// target: "www.google.com" returns host: "www.google.com", port: "443"
// target: "ipv4-host:80" returns host: "ipv4-host", port: "80"
// target: "[ipv6-host]" returns host: "ipv6-host", port: "443"
// target: ":80" returns host: "localhost", port: "80"
// target: ":" returns host: "localhost", port: "443"
func parseTarget(target string) (host, port string, err error) {
// target: "www.google.com" defaultPort: "443" returns host: "www.google.com", port: "443"
// target: "ipv4-host:80" defaultPort: "443" returns host: "ipv4-host", port: "80"
// target: "[ipv6-host]" defaultPort: "443" returns host: "ipv6-host", port: "443"
// target: ":80" defaultPort: "443" returns host: "localhost", port: "80"
func parseTarget(target, defaultPort string) (host, port string, err error) {
if target == "" {
return "", "", errMissingAddr
}
@ -305,15 +364,15 @@ func parseTarget(target string) (host, port string, err error) {
return target, defaultPort, nil
}
if host, port, err = net.SplitHostPort(target); err == nil {
if port == "" {
// If the port field is empty (target ends with colon), e.g. "[::1]:", this is an error.
return "", "", errEndsWithColon
}
// target has port, i.e ipv4-host:port, [ipv6-host]:port, host-name:port
if host == "" {
// Keep consistent with net.Dial(): If the host is empty, as in ":80", the local system is assumed.
host = "localhost"
}
if port == "" {
// If the port field is empty(target ends with colon), e.g. "[::1]:", defaultPort is used.
port = defaultPort
}
return host, port, nil
}
if host, port, err = net.SplitHostPort(target + ":" + defaultPort); err == nil {
@ -346,7 +405,7 @@ func chosenByPercentage(a *int) bool {
if a == nil {
return true
}
return randomGen.Intn(100)+1 <= *a
return grpcrand.Intn(100)+1 <= *a
}
func canaryingSC(js string) string {

View file

@ -1,35 +0,0 @@
// +build go1.6, !go1.8
/*
*
* Copyright 2017 gRPC authors.
*
* 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 dns
import (
"net"
"golang.org/x/net/context"
)
var (
lookupHost = func(ctx context.Context, host string) ([]string, error) { return net.LookupHost(host) }
lookupSRV = func(ctx context.Context, service, proto, name string) (string, []*net.SRV, error) {
return net.LookupSRV(service, proto, name)
}
lookupTXT = func(ctx context.Context, name string) ([]string, error) { return net.LookupTXT(name) }
)

View file

@ -1,29 +0,0 @@
// +build go1.8
/*
*
* Copyright 2017 gRPC authors.
*
* 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 dns
import "net"
var (
lookupHost = net.DefaultResolver.LookupHost
lookupSRV = net.DefaultResolver.LookupSRV
lookupTXT = net.DefaultResolver.LookupTXT
)

View file

@ -45,7 +45,7 @@ type passthroughResolver struct {
}
func (r *passthroughResolver) start() {
r.cc.NewAddress([]resolver.Address{{Addr: r.target.Endpoint}})
r.cc.UpdateState(resolver.State{Addresses: []resolver.Address{{Addr: r.target.Endpoint}}})
}
func (*passthroughResolver) ResolveNow(o resolver.ResolveNowOption) {}

View file

@ -49,8 +49,12 @@ func Get(scheme string) Builder {
return nil
}
// SetDefaultScheme sets the default scheme that will be used.
// The default default scheme is "passthrough".
// SetDefaultScheme sets the default scheme that will be used. The default
// default scheme is "passthrough".
//
// NOTE: this function must only be called during initialization time (i.e. in
// an init() function), and is not thread-safe. The scheme set last overrides
// previously set values.
func SetDefaultScheme(scheme string) {
defaultScheme = scheme
}
@ -94,6 +98,15 @@ type BuildOption struct {
DisableServiceConfig bool
}
// State contains the current Resolver state relevant to the ClientConn.
type State struct {
Addresses []Address // Resolved addresses for the target
ServiceConfig string // JSON representation of the service config
// TODO: add Err error
// TODO: add ParsedServiceConfig interface{}
}
// ClientConn contains the callbacks for resolver to notify any updates
// to the gRPC ClientConn.
//
@ -102,12 +115,18 @@ type BuildOption struct {
// testing, the new implementation should embed this interface. This allows
// gRPC to add new methods to this interface.
type ClientConn interface {
// UpdateState updates the state of the ClientConn appropriately.
UpdateState(State)
// NewAddress is called by resolver to notify ClientConn a new list
// of resolved addresses.
// The address list should be the complete list of resolved addresses.
//
// Deprecated: Use UpdateState instead.
NewAddress(addresses []Address)
// NewServiceConfig is called by resolver to notify ClientConn a new
// service config. The service config should be provided as a json string.
//
// Deprecated: Use UpdateState instead.
NewServiceConfig(serviceConfig string)
}