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advanced-go-programming-book/examples/google.golang.org/grpc/resolver/dns/dns_resolver_test.go
chai2010 3b792286a6 rename vendor examples
2018-12-15 00:26:58 +08:00

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/*
*
* 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 (
"fmt"
"net"
"os"
"reflect"
"sync"
"testing"
"time"
"google.golang.org/grpc/internal/leakcheck"
"google.golang.org/grpc/resolver"
)
func TestMain(m *testing.M) {
cleanup := replaceNetFunc()
code := m.Run()
cleanup()
os.Exit(code)
}
const (
txtBytesLimit = 255
)
type testClientConn struct {
target string
m1 sync.Mutex
addrs []resolver.Address
a int
m2 sync.Mutex
sc string
s int
}
func (t *testClientConn) NewAddress(addresses []resolver.Address) {
t.m1.Lock()
defer t.m1.Unlock()
t.addrs = addresses
t.a++
}
func (t *testClientConn) getAddress() ([]resolver.Address, int) {
t.m1.Lock()
defer t.m1.Unlock()
return t.addrs, t.a
}
func (t *testClientConn) NewServiceConfig(serviceConfig string) {
t.m2.Lock()
defer t.m2.Unlock()
t.sc = serviceConfig
t.s++
}
func (t *testClientConn) getSc() (string, int) {
t.m2.Lock()
defer t.m2.Unlock()
return t.sc, t.s
}
var hostLookupTbl = struct {
sync.Mutex
tbl map[string][]string
}{
tbl: map[string][]string{
"foo.bar.com": {"1.2.3.4", "5.6.7.8"},
"ipv4.single.fake": {"1.2.3.4"},
"srv.ipv4.single.fake": {"2.4.6.8"},
"ipv4.multi.fake": {"1.2.3.4", "5.6.7.8", "9.10.11.12"},
"ipv6.single.fake": {"2607:f8b0:400a:801::1001"},
"ipv6.multi.fake": {"2607:f8b0:400a:801::1001", "2607:f8b0:400a:801::1002", "2607:f8b0:400a:801::1003"},
},
}
func hostLookup(host string) ([]string, error) {
hostLookupTbl.Lock()
defer hostLookupTbl.Unlock()
if addrs, cnt := hostLookupTbl.tbl[host]; cnt {
return addrs, nil
}
return nil, fmt.Errorf("failed to lookup host:%s resolution in hostLookupTbl", host)
}
var srvLookupTbl = struct {
sync.Mutex
tbl map[string][]*net.SRV
}{
tbl: map[string][]*net.SRV{
"_grpclb._tcp.srv.ipv4.single.fake": {&net.SRV{Target: "ipv4.single.fake", Port: 1234}},
"_grpclb._tcp.srv.ipv4.multi.fake": {&net.SRV{Target: "ipv4.multi.fake", Port: 1234}},
"_grpclb._tcp.srv.ipv6.single.fake": {&net.SRV{Target: "ipv6.single.fake", Port: 1234}},
"_grpclb._tcp.srv.ipv6.multi.fake": {&net.SRV{Target: "ipv6.multi.fake", Port: 1234}},
},
}
func srvLookup(service, proto, name string) (string, []*net.SRV, error) {
cname := "_" + service + "._" + proto + "." + name
srvLookupTbl.Lock()
defer srvLookupTbl.Unlock()
if srvs, cnt := srvLookupTbl.tbl[cname]; cnt {
return cname, srvs, nil
}
return "", nil, fmt.Errorf("failed to lookup srv record for %s in srvLookupTbl", cname)
}
// div divides a byte slice into a slice of strings, each of which is of maximum
// 255 bytes length, which is the length limit per TXT record in DNS.
func div(b []byte) []string {
var r []string
for i := 0; i < len(b); i += txtBytesLimit {
if i+txtBytesLimit > len(b) {
r = append(r, string(b[i:]))
} else {
r = append(r, string(b[i:i+txtBytesLimit]))
}
}
return r
}
// scfs contains an array of service config file string in JSON format.
// Notes about the scfs contents and usage:
// scfs contains 4 service config file JSON strings for testing. Inside each
// service config file, there are multiple choices. scfs[0:3] each contains 5
// choices, and first 3 choices are nonmatching choices based on canarying rule,
// while the last two are matched choices. scfs[3] only contains 3 choices, and
// all of them are nonmatching based on canarying rule. For each of scfs[0:3],
// the eventually returned service config, which is from the first of the two
// matched choices, is stored in the corresponding scs element (e.g.
// scfs[0]->scs[0]). scfs and scs elements are used in pair to test the dns
// resolver functionality, with scfs as the input and scs used for validation of
// the output. For scfs[3], it corresponds to empty service config, since there
// isn't a matched choice.
var scfs = []string{
`[
{
"clientLanguage": [
"CPP",
"JAVA"
],
"serviceConfig": {
"loadBalancingPolicy": "grpclb",
"methodConfig": [
{
"name": [
{
"service": "all"
}
],
"timeout": "1s"
}
]
}
},
{
"percentage": 0,
"serviceConfig": {
"loadBalancingPolicy": "grpclb",
"methodConfig": [
{
"name": [
{
"service": "all"
}
],
"timeout": "1s"
}
]
}
},
{
"clientHostName": [
"localhost"
],
"serviceConfig": {
"loadBalancingPolicy": "grpclb",
"methodConfig": [
{
"name": [
{
"service": "all"
}
],
"timeout": "1s"
}
]
}
},
{
"clientLanguage": [
"GO"
],
"percentage": 100,
"serviceConfig": {
"methodConfig": [
{
"name": [
{
"method": "bar"
}
],
"maxRequestMessageBytes": 1024,
"maxResponseMessageBytes": 1024
}
]
}
},
{
"serviceConfig": {
"loadBalancingPolicy": "round_robin",
"methodConfig": [
{
"name": [
{
"service": "foo",
"method": "bar"
}
],
"waitForReady": true
}
]
}
}
]`,
`[
{
"clientLanguage": [
"CPP",
"JAVA"
],
"serviceConfig": {
"loadBalancingPolicy": "grpclb",
"methodConfig": [
{
"name": [
{
"service": "all"
}
],
"timeout": "1s"
}
]
}
},
{
"percentage": 0,
"serviceConfig": {
"loadBalancingPolicy": "grpclb",
"methodConfig": [
{
"name": [
{
"service": "all"
}
],
"timeout": "1s"
}
]
}
},
{
"clientHostName": [
"localhost"
],
"serviceConfig": {
"loadBalancingPolicy": "grpclb",
"methodConfig": [
{
"name": [
{
"service": "all"
}
],
"timeout": "1s"
}
]
}
},
{
"clientLanguage": [
"GO"
],
"percentage": 100,
"serviceConfig": {
"methodConfig": [
{
"name": [
{
"service": "foo",
"method": "bar"
}
],
"waitForReady": true,
"timeout": "1s",
"maxRequestMessageBytes": 1024,
"maxResponseMessageBytes": 1024
}
]
}
},
{
"serviceConfig": {
"loadBalancingPolicy": "round_robin",
"methodConfig": [
{
"name": [
{
"service": "foo",
"method": "bar"
}
],
"waitForReady": true
}
]
}
}
]`,
`[
{
"clientLanguage": [
"CPP",
"JAVA"
],
"serviceConfig": {
"loadBalancingPolicy": "grpclb",
"methodConfig": [
{
"name": [
{
"service": "all"
}
],
"timeout": "1s"
}
]
}
},
{
"percentage": 0,
"serviceConfig": {
"loadBalancingPolicy": "grpclb",
"methodConfig": [
{
"name": [
{
"service": "all"
}
],
"timeout": "1s"
}
]
}
},
{
"clientHostName": [
"localhost"
],
"serviceConfig": {
"loadBalancingPolicy": "grpclb",
"methodConfig": [
{
"name": [
{
"service": "all"
}
],
"timeout": "1s"
}
]
}
},
{
"clientLanguage": [
"GO"
],
"percentage": 100,
"serviceConfig": {
"loadBalancingPolicy": "round_robin",
"methodConfig": [
{
"name": [
{
"service": "foo"
}
],
"waitForReady": true,
"timeout": "1s"
},
{
"name": [
{
"service": "bar"
}
],
"waitForReady": false
}
]
}
},
{
"serviceConfig": {
"loadBalancingPolicy": "round_robin",
"methodConfig": [
{
"name": [
{
"service": "foo",
"method": "bar"
}
],
"waitForReady": true
}
]
}
}
]`,
`[
{
"clientLanguage": [
"CPP",
"JAVA"
],
"serviceConfig": {
"loadBalancingPolicy": "grpclb",
"methodConfig": [
{
"name": [
{
"service": "all"
}
],
"timeout": "1s"
}
]
}
},
{
"percentage": 0,
"serviceConfig": {
"loadBalancingPolicy": "grpclb",
"methodConfig": [
{
"name": [
{
"service": "all"
}
],
"timeout": "1s"
}
]
}
},
{
"clientHostName": [
"localhost"
],
"serviceConfig": {
"loadBalancingPolicy": "grpclb",
"methodConfig": [
{
"name": [
{
"service": "all"
}
],
"timeout": "1s"
}
]
}
}
]`,
}
// scs contains an array of service config string in JSON format.
var scs = []string{
`{
"methodConfig": [
{
"name": [
{
"method": "bar"
}
],
"maxRequestMessageBytes": 1024,
"maxResponseMessageBytes": 1024
}
]
}`,
`{
"methodConfig": [
{
"name": [
{
"service": "foo",
"method": "bar"
}
],
"waitForReady": true,
"timeout": "1s",
"maxRequestMessageBytes": 1024,
"maxResponseMessageBytes": 1024
}
]
}`,
`{
"loadBalancingPolicy": "round_robin",
"methodConfig": [
{
"name": [
{
"service": "foo"
}
],
"waitForReady": true,
"timeout": "1s"
},
{
"name": [
{
"service": "bar"
}
],
"waitForReady": false
}
]
}`,
}
// scLookupTbl is a set, which contains targets that have service config. Target
// not in this set should not have service config.
var scLookupTbl = map[string]bool{
"foo.bar.com": true,
"srv.ipv4.single.fake": true,
"srv.ipv4.multi.fake": true,
"no.attribute": true,
}
// generateSCF generates a slice of strings (aggregately representing a single
// service config file) for the input name, which mocks the result from a real
// DNS TXT record lookup.
func generateSCF(name string) []string {
var b []byte
switch name {
case "foo.bar.com":
b = []byte(scfs[0])
case "srv.ipv4.single.fake":
b = []byte(scfs[1])
case "srv.ipv4.multi.fake":
b = []byte(scfs[2])
default:
b = []byte(scfs[3])
}
if name == "no.attribute" {
return div(b)
}
return div(append([]byte(txtAttribute), b...))
}
// generateSC returns a service config string in JSON format for the input name.
func generateSC(name string) string {
_, cnt := scLookupTbl[name]
if !cnt || name == "no.attribute" {
return ""
}
switch name {
case "foo.bar.com":
return scs[0]
case "srv.ipv4.single.fake":
return scs[1]
case "srv.ipv4.multi.fake":
return scs[2]
default:
return ""
}
}
var txtLookupTbl = struct {
sync.Mutex
tbl map[string][]string
}{
tbl: map[string][]string{
"foo.bar.com": generateSCF("foo.bar.com"),
"srv.ipv4.single.fake": generateSCF("srv.ipv4.single.fake"),
"srv.ipv4.multi.fake": generateSCF("srv.ipv4.multi.fake"),
"srv.ipv6.single.fake": generateSCF("srv.ipv6.single.fake"),
"srv.ipv6.multi.fake": generateSCF("srv.ipv6.multi.fake"),
"no.attribute": generateSCF("no.attribute"),
},
}
func txtLookup(host string) ([]string, error) {
txtLookupTbl.Lock()
defer txtLookupTbl.Unlock()
if scs, cnt := txtLookupTbl.tbl[host]; cnt {
return scs, nil
}
return nil, fmt.Errorf("failed to lookup TXT:%s resolution in txtLookupTbl", host)
}
func TestResolve(t *testing.T) {
testDNSResolver(t)
testDNSResolveNow(t)
testIPResolver(t)
}
func testDNSResolver(t *testing.T) {
defer leakcheck.Check(t)
tests := []struct {
target string
addrWant []resolver.Address
scWant string
}{
{
"foo.bar.com",
[]resolver.Address{{Addr: "1.2.3.4" + colonDefaultPort}, {Addr: "5.6.7.8" + colonDefaultPort}},
generateSC("foo.bar.com"),
},
{
"foo.bar.com:1234",
[]resolver.Address{{Addr: "1.2.3.4:1234"}, {Addr: "5.6.7.8:1234"}},
generateSC("foo.bar.com"),
},
{
"srv.ipv4.single.fake",
[]resolver.Address{{Addr: "1.2.3.4:1234", Type: resolver.GRPCLB, ServerName: "ipv4.single.fake"}, {Addr: "2.4.6.8" + colonDefaultPort}},
generateSC("srv.ipv4.single.fake"),
},
{
"srv.ipv4.multi.fake",
[]resolver.Address{
{Addr: "1.2.3.4:1234", Type: resolver.GRPCLB, ServerName: "ipv4.multi.fake"},
{Addr: "5.6.7.8:1234", Type: resolver.GRPCLB, ServerName: "ipv4.multi.fake"},
{Addr: "9.10.11.12:1234", Type: resolver.GRPCLB, ServerName: "ipv4.multi.fake"},
},
generateSC("srv.ipv4.multi.fake"),
},
{
"srv.ipv6.single.fake",
[]resolver.Address{{Addr: "[2607:f8b0:400a:801::1001]:1234", Type: resolver.GRPCLB, ServerName: "ipv6.single.fake"}},
generateSC("srv.ipv6.single.fake"),
},
{
"srv.ipv6.multi.fake",
[]resolver.Address{
{Addr: "[2607:f8b0:400a:801::1001]:1234", Type: resolver.GRPCLB, ServerName: "ipv6.multi.fake"},
{Addr: "[2607:f8b0:400a:801::1002]:1234", Type: resolver.GRPCLB, ServerName: "ipv6.multi.fake"},
{Addr: "[2607:f8b0:400a:801::1003]:1234", Type: resolver.GRPCLB, ServerName: "ipv6.multi.fake"},
},
generateSC("srv.ipv6.multi.fake"),
},
{
"no.attribute",
nil,
generateSC("no.attribute"),
},
}
for _, a := range tests {
b := NewBuilder()
cc := &testClientConn{target: a.target}
r, err := b.Build(resolver.Target{Endpoint: a.target}, cc, resolver.BuildOption{})
if err != nil {
t.Fatalf("%v\n", err)
}
var addrs []resolver.Address
var cnt int
for {
addrs, cnt = cc.getAddress()
if cnt > 0 {
break
}
time.Sleep(time.Millisecond)
}
var sc string
for {
sc, cnt = cc.getSc()
if cnt > 0 {
break
}
time.Sleep(time.Millisecond)
}
if !reflect.DeepEqual(a.addrWant, addrs) {
t.Errorf("Resolved addresses of target: %q = %+v, want %+v\n", a.target, addrs, a.addrWant)
}
if !reflect.DeepEqual(a.scWant, sc) {
t.Errorf("Resolved service config of target: %q = %+v, want %+v\n", a.target, sc, a.scWant)
}
r.Close()
}
}
func mutateTbl(target string) func() {
hostLookupTbl.Lock()
oldHostTblEntry := hostLookupTbl.tbl[target]
hostLookupTbl.tbl[target] = hostLookupTbl.tbl[target][:len(oldHostTblEntry)-1]
hostLookupTbl.Unlock()
txtLookupTbl.Lock()
oldTxtTblEntry := txtLookupTbl.tbl[target]
txtLookupTbl.tbl[target] = []string{""}
txtLookupTbl.Unlock()
return func() {
hostLookupTbl.Lock()
hostLookupTbl.tbl[target] = oldHostTblEntry
hostLookupTbl.Unlock()
txtLookupTbl.Lock()
txtLookupTbl.tbl[target] = oldTxtTblEntry
txtLookupTbl.Unlock()
}
}
func testDNSResolveNow(t *testing.T) {
defer leakcheck.Check(t)
tests := []struct {
target string
addrWant []resolver.Address
addrNext []resolver.Address
scWant string
scNext string
}{
{
"foo.bar.com",
[]resolver.Address{{Addr: "1.2.3.4" + colonDefaultPort}, {Addr: "5.6.7.8" + colonDefaultPort}},
[]resolver.Address{{Addr: "1.2.3.4" + colonDefaultPort}},
generateSC("foo.bar.com"),
"",
},
}
for _, a := range tests {
b := NewBuilder()
cc := &testClientConn{target: a.target}
r, err := b.Build(resolver.Target{Endpoint: a.target}, cc, resolver.BuildOption{})
if err != nil {
t.Fatalf("%v\n", err)
}
var addrs []resolver.Address
var cnt int
for {
addrs, cnt = cc.getAddress()
if cnt > 0 {
break
}
time.Sleep(time.Millisecond)
}
var sc string
for {
sc, cnt = cc.getSc()
if cnt > 0 {
break
}
time.Sleep(time.Millisecond)
}
if !reflect.DeepEqual(a.addrWant, addrs) {
t.Errorf("Resolved addresses of target: %q = %+v, want %+v\n", a.target, addrs, a.addrWant)
}
if !reflect.DeepEqual(a.scWant, sc) {
t.Errorf("Resolved service config of target: %q = %+v, want %+v\n", a.target, sc, a.scWant)
}
revertTbl := mutateTbl(a.target)
r.ResolveNow(resolver.ResolveNowOption{})
for {
addrs, cnt = cc.getAddress()
if cnt == 2 {
break
}
time.Sleep(time.Millisecond)
}
for {
sc, cnt = cc.getSc()
if cnt == 2 {
break
}
time.Sleep(time.Millisecond)
}
if !reflect.DeepEqual(a.addrNext, addrs) {
t.Errorf("Resolved addresses of target: %q = %+v, want %+v\n", a.target, addrs, a.addrNext)
}
if !reflect.DeepEqual(a.scNext, sc) {
t.Errorf("Resolved service config of target: %q = %+v, want %+v\n", a.target, sc, a.scNext)
}
revertTbl()
r.Close()
}
}
const colonDefaultPort = ":" + defaultPort
func testIPResolver(t *testing.T) {
defer leakcheck.Check(t)
tests := []struct {
target string
want []resolver.Address
}{
{"127.0.0.1", []resolver.Address{{Addr: "127.0.0.1" + colonDefaultPort}}},
{"127.0.0.1:12345", []resolver.Address{{Addr: "127.0.0.1:12345"}}},
{"::1", []resolver.Address{{Addr: "[::1]" + colonDefaultPort}}},
{"[::1]:12345", []resolver.Address{{Addr: "[::1]:12345"}}},
{"[::1]:", []resolver.Address{{Addr: "[::1]:443"}}},
{"2001:db8:85a3::8a2e:370:7334", []resolver.Address{{Addr: "[2001:db8:85a3::8a2e:370:7334]" + colonDefaultPort}}},
{"[2001:db8:85a3::8a2e:370:7334]", []resolver.Address{{Addr: "[2001:db8:85a3::8a2e:370:7334]" + colonDefaultPort}}},
{"[2001:db8:85a3::8a2e:370:7334]:12345", []resolver.Address{{Addr: "[2001:db8:85a3::8a2e:370:7334]:12345"}}},
{"[2001:db8::1]:http", []resolver.Address{{Addr: "[2001:db8::1]:http"}}},
// TODO(yuxuanli): zone support?
}
for _, v := range tests {
b := NewBuilder()
cc := &testClientConn{target: v.target}
r, err := b.Build(resolver.Target{Endpoint: v.target}, cc, resolver.BuildOption{})
if err != nil {
t.Fatalf("%v\n", err)
}
var addrs []resolver.Address
var cnt int
for {
addrs, cnt = cc.getAddress()
if cnt > 0 {
break
}
time.Sleep(time.Millisecond)
}
if !reflect.DeepEqual(v.want, addrs) {
t.Errorf("Resolved addresses of target: %q = %+v, want %+v\n", v.target, addrs, v.want)
}
r.ResolveNow(resolver.ResolveNowOption{})
for {
addrs, cnt = cc.getAddress()
if cnt == 2 {
break
}
time.Sleep(time.Millisecond)
}
if !reflect.DeepEqual(v.want, addrs) {
t.Errorf("Resolved addresses of target: %q = %+v, want %+v\n", v.target, addrs, v.want)
}
r.Close()
}
}
func TestResolveFunc(t *testing.T) {
defer leakcheck.Check(t)
tests := []struct {
addr string
want error
}{
// TODO(yuxuanli): More false cases?
{"www.google.com", nil},
{"foo.bar:12345", nil},
{"127.0.0.1", nil},
{"127.0.0.1:12345", nil},
{"[::1]:80", nil},
{"[2001:db8:a0b:12f0::1]:21", nil},
{":80", nil},
{"127.0.0...1:12345", nil},
{"[fe80::1%lo0]:80", nil},
{"golang.org:http", nil},
{"[2001:db8::1]:http", nil},
{":", nil},
{"", errMissingAddr},
{"[2001:db8:a0b:12f0::1", errForInvalidTarget},
}
b := NewBuilder()
for _, v := range tests {
cc := &testClientConn{target: v.addr}
r, err := b.Build(resolver.Target{Endpoint: v.addr}, cc, resolver.BuildOption{})
if err == nil {
r.Close()
}
if !reflect.DeepEqual(err, v.want) {
t.Errorf("Build(%q, cc, resolver.BuildOption{}) = %v, want %v", v.addr, err, v.want)
}
}
}
func TestDisableServiceConfig(t *testing.T) {
defer leakcheck.Check(t)
tests := []struct {
target string
scWant string
disableServiceConfig bool
}{
{
"foo.bar.com",
generateSC("foo.bar.com"),
false,
},
{
"foo.bar.com",
"",
true,
},
}
for _, a := range tests {
b := NewBuilder()
cc := &testClientConn{target: a.target}
r, err := b.Build(resolver.Target{Endpoint: a.target}, cc, resolver.BuildOption{DisableServiceConfig: a.disableServiceConfig})
if err != nil {
t.Fatalf("%v\n", err)
}
var cnt int
var sc string
for {
sc, cnt = cc.getSc()
if cnt > 0 {
break
}
time.Sleep(time.Millisecond)
}
if !reflect.DeepEqual(a.scWant, sc) {
t.Errorf("Resolved service config of target: %q = %+v, want %+v\n", a.target, sc, a.scWant)
}
r.Close()
}
}
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