rls: Implementation of RLS key builders. (#3344)

This commit is contained in:
Easwar Swaminathan
2020-02-06 20:57:36 -08:00
committed by GitHub
parent 979f0a2f08
commit d76e57cb09
2 changed files with 506 additions and 0 deletions

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// +build !appengine
/*
*
* Copyright 2020 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 keys provides functionality required to build RLS request keys.
package keys
import (
"errors"
"fmt"
"sort"
"strings"
rlspb "google.golang.org/grpc/balancer/rls/internal/proto/grpc_lookup_v1"
"google.golang.org/grpc/metadata"
)
// BuilderMap provides a mapping from a request path to the key builder to be
// used for that path.
// The BuilderMap is constructed by parsing the RouteLookupConfig received by
// the RLS balancer as part of its ServiceConfig, and is used by the picker in
// the data path to build the RLS keys to be used for a given request.
type BuilderMap map[string]builder
// MakeBuilderMap parses the provided RouteLookupConfig proto and returns a map
// from paths to key builders.
//
// The following conditions are validated, and an error is returned if any of
// them is not met:
// grpc_keybuilders field
// * must have at least one entry
// * must not have two entries with the same Name
// * must not have any entry with a Name with the service field unset or empty
// * must not have any entries without a Name
// * must not have a headers entry that has required_match set
// * must not have two headers entries with the same key within one entry
func MakeBuilderMap(cfg *rlspb.RouteLookupConfig) (BuilderMap, error) {
kbs := cfg.GetGrpcKeybuilders()
if len(kbs) == 0 {
return nil, errors.New("rls: RouteLookupConfig does not contain any GrpcKeyBuilder")
}
bm := make(map[string]builder)
for _, kb := range kbs {
var matchers []matcher
seenKeys := make(map[string]bool)
for _, h := range kb.GetHeaders() {
if h.GetRequiredMatch() {
return nil, fmt.Errorf("rls: GrpcKeyBuilder in RouteLookupConfig has required_match field set {%+v}", kbs)
}
key := h.GetKey()
if seenKeys[key] {
return nil, fmt.Errorf("rls: GrpcKeyBuilder in RouteLookupConfig contains repeated Key field in headers {%+v}", kbs)
}
seenKeys[key] = true
matchers = append(matchers, matcher{key: h.GetKey(), names: h.GetNames()})
}
b := builder{matchers: matchers}
names := kb.GetNames()
if len(names) == 0 {
return nil, fmt.Errorf("rls: GrpcKeyBuilder in RouteLookupConfig does not contain any Name {%+v}", kbs)
}
for _, name := range names {
if name.GetService() == "" {
return nil, fmt.Errorf("rls: GrpcKeyBuilder in RouteLookupConfig contains a Name field with no Service {%+v}", kbs)
}
if strings.Contains(name.GetMethod(), `/`) {
return nil, fmt.Errorf("rls: GrpcKeyBuilder in RouteLookupConfig contains a method with a slash {%+v}", kbs)
}
path := "/" + name.GetService() + "/" + name.GetMethod()
if _, ok := bm[path]; ok {
return nil, fmt.Errorf("rls: GrpcKeyBuilder in RouteLookupConfig contains repeated Name field {%+v}", kbs)
}
bm[path] = b
}
}
return bm, nil
}
// KeyMap represents the RLS keys to be used for a request.
type KeyMap struct {
// Map is the representation of an RLS key as a Go map. This is used when
// an actual RLS request is to be sent out on the wire, since the
// RouteLookupRequest proto expects a Go map.
Map map[string]string
// Str is the representation of an RLS key as a string, sorted by keys.
// Since the RLS keys are part of the cache key in the request cache
// maintained by the RLS balancer, and Go maps cannot be used as keys for
// Go maps (the cache is implemented as a map), we need a stringified
// version of it.
Str string
}
// RLSKey builds the RLS keys to be used for the given request, identified by
// the request path and the request headers stored in metadata.
func (bm BuilderMap) RLSKey(md metadata.MD, path string) KeyMap {
b, ok := bm[path]
if !ok {
i := strings.LastIndex(path, "/")
b, ok = bm[path[:i+1]]
if !ok {
return KeyMap{}
}
}
return b.keys(md)
}
// builder provides the actual functionality of building RLS keys. These are
// stored in the BuilderMap.
// While processing a pick, the picker looks in the BuilderMap for the
// appropriate builder to be used for the given RPC. For each of the matchers
// in the found builder, we iterate over the list of request headers (available
// as metadata in the context). Once a header matches one of the names in the
// matcher, we set the value of the header in the keyMap (with the key being
// the one found in the matcher) and move on to the next matcher. If no
// KeyBuilder was found in the map, or no header match was found, an empty
// keyMap is returned.
type builder struct {
matchers []matcher
}
// matcher helps extract a key from request headers based on a given name.
type matcher struct {
// The key used in the keyMap sent as part of the RLS request.
key string
// List of header names which can supply the value for this key.
names []string
}
func (b builder) keys(md metadata.MD) KeyMap {
kvMap := make(map[string]string)
for _, m := range b.matchers {
for _, name := range m.names {
if vals := md.Get(name); vals != nil {
kvMap[m.key] = strings.Join(vals, ",")
break
}
}
}
return KeyMap{Map: kvMap, Str: mapToString(kvMap)}
}
func mapToString(kv map[string]string) string {
var keys []string
for k := range kv {
keys = append(keys, k)
}
sort.Strings(keys)
var sb strings.Builder
for i, k := range keys {
if i != 0 {
fmt.Fprint(&sb, ",")
}
fmt.Fprintf(&sb, "%s=%s", k, kv[k])
}
return sb.String()
}

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// +build !appengine
/*
*
* Copyright 2020 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 keys
import (
"fmt"
"strings"
"testing"
"github.com/google/go-cmp/cmp"
rlspb "google.golang.org/grpc/balancer/rls/internal/proto/grpc_lookup_v1"
"google.golang.org/grpc/metadata"
)
var (
goodKeyBuilder1 = &rlspb.GrpcKeyBuilder{
Names: []*rlspb.GrpcKeyBuilder_Name{
{Service: "gFoo"},
},
Headers: []*rlspb.NameMatcher{
{Key: "k1", Names: []string{"n1"}},
{Key: "k2", Names: []string{"n1"}},
},
}
goodKeyBuilder2 = &rlspb.GrpcKeyBuilder{
Names: []*rlspb.GrpcKeyBuilder_Name{
{Service: "gBar", Method: "method1"},
{Service: "gFoobar"},
},
Headers: []*rlspb.NameMatcher{
{Key: "k1", Names: []string{"n1", "n2"}},
},
}
)
func TestMakeBuilderMap(t *testing.T) {
wantBuilderMap1 := map[string]builder{
"/gFoo/": {matchers: []matcher{{key: "k1", names: []string{"n1"}}, {key: "k2", names: []string{"n1"}}}},
}
wantBuilderMap2 := map[string]builder{
"/gFoo/": {matchers: []matcher{{key: "k1", names: []string{"n1"}}, {key: "k2", names: []string{"n1"}}}},
"/gBar/method1": {matchers: []matcher{{key: "k1", names: []string{"n1", "n2"}}}},
"/gFoobar/": {matchers: []matcher{{key: "k1", names: []string{"n1", "n2"}}}},
}
tests := []struct {
desc string
cfg *rlspb.RouteLookupConfig
wantBuilderMap BuilderMap
}{
{
desc: "One good GrpcKeyBuilder",
cfg: &rlspb.RouteLookupConfig{
GrpcKeybuilders: []*rlspb.GrpcKeyBuilder{goodKeyBuilder1},
},
wantBuilderMap: wantBuilderMap1,
},
{
desc: "Two good GrpcKeyBuilders",
cfg: &rlspb.RouteLookupConfig{
GrpcKeybuilders: []*rlspb.GrpcKeyBuilder{goodKeyBuilder1, goodKeyBuilder2},
},
wantBuilderMap: wantBuilderMap2,
},
}
for _, test := range tests {
t.Run(test.desc, func(t *testing.T) {
builderMap, err := MakeBuilderMap(test.cfg)
if err != nil || !cmp.Equal(builderMap, test.wantBuilderMap, cmp.AllowUnexported(builder{}, matcher{})) {
t.Errorf("MakeBuilderMap(%+v) returned {%v, %v}, want: {%v, nil}", test.cfg, builderMap, err, test.wantBuilderMap)
}
})
}
}
func TestMakeBuilderMapErrors(t *testing.T) {
emptyServiceKeyBuilder := &rlspb.GrpcKeyBuilder{
Names: []*rlspb.GrpcKeyBuilder_Name{
{Service: "bFoo", Method: "method1"},
{Service: "bBar"},
{Method: "method1"},
},
Headers: []*rlspb.NameMatcher{{Key: "k1", Names: []string{"n1", "n2"}}},
}
requiredMatchKeyBuilder := &rlspb.GrpcKeyBuilder{
Names: []*rlspb.GrpcKeyBuilder_Name{{Service: "bFoo", Method: "method1"}},
Headers: []*rlspb.NameMatcher{{Key: "k1", Names: []string{"n1", "n2"}, RequiredMatch: true}},
}
repeatedHeadersKeyBuilder := &rlspb.GrpcKeyBuilder{
Names: []*rlspb.GrpcKeyBuilder_Name{
{Service: "gBar", Method: "method1"},
{Service: "gFoobar"},
},
Headers: []*rlspb.NameMatcher{
{Key: "k1", Names: []string{"n1", "n2"}},
{Key: "k1", Names: []string{"n1", "n2"}},
},
}
methodNameWithSlashKeyBuilder := &rlspb.GrpcKeyBuilder{
Names: []*rlspb.GrpcKeyBuilder_Name{{Service: "gBar", Method: "method1/foo"}},
Headers: []*rlspb.NameMatcher{{Key: "k1", Names: []string{"n1", "n2"}}},
}
tests := []struct {
desc string
cfg *rlspb.RouteLookupConfig
wantErrPrefix string
}{
{
desc: "No GrpcKeyBuilder",
cfg: &rlspb.RouteLookupConfig{},
wantErrPrefix: "rls: RouteLookupConfig does not contain any GrpcKeyBuilder",
},
{
desc: "Two GrpcKeyBuilders with same Name",
cfg: &rlspb.RouteLookupConfig{
GrpcKeybuilders: []*rlspb.GrpcKeyBuilder{goodKeyBuilder1, goodKeyBuilder1},
},
wantErrPrefix: "rls: GrpcKeyBuilder in RouteLookupConfig contains repeated Name field",
},
{
desc: "GrpcKeyBuilder with empty Service field",
cfg: &rlspb.RouteLookupConfig{
GrpcKeybuilders: []*rlspb.GrpcKeyBuilder{emptyServiceKeyBuilder, goodKeyBuilder1},
},
wantErrPrefix: "rls: GrpcKeyBuilder in RouteLookupConfig contains a Name field with no Service",
},
{
desc: "GrpcKeyBuilder with no Name",
cfg: &rlspb.RouteLookupConfig{
GrpcKeybuilders: []*rlspb.GrpcKeyBuilder{{}, goodKeyBuilder1},
},
wantErrPrefix: "rls: GrpcKeyBuilder in RouteLookupConfig does not contain any Name",
},
{
desc: "GrpcKeyBuilder with requiredMatch field set",
cfg: &rlspb.RouteLookupConfig{
GrpcKeybuilders: []*rlspb.GrpcKeyBuilder{requiredMatchKeyBuilder, goodKeyBuilder1},
},
wantErrPrefix: "rls: GrpcKeyBuilder in RouteLookupConfig has required_match field set",
},
{
desc: "GrpcKeyBuilder two headers with same key",
cfg: &rlspb.RouteLookupConfig{
GrpcKeybuilders: []*rlspb.GrpcKeyBuilder{repeatedHeadersKeyBuilder, goodKeyBuilder1},
},
wantErrPrefix: "rls: GrpcKeyBuilder in RouteLookupConfig contains repeated Key field in headers",
},
{
desc: "GrpcKeyBuilder with slash in method name",
cfg: &rlspb.RouteLookupConfig{
GrpcKeybuilders: []*rlspb.GrpcKeyBuilder{methodNameWithSlashKeyBuilder},
},
wantErrPrefix: "rls: GrpcKeyBuilder in RouteLookupConfig contains a method with a slash",
},
}
for _, test := range tests {
t.Run(test.desc, func(t *testing.T) {
builderMap, err := MakeBuilderMap(test.cfg)
if builderMap != nil || !strings.HasPrefix(fmt.Sprint(err), test.wantErrPrefix) {
t.Errorf("MakeBuilderMap(%+v) returned {%v, %v}, want: {nil, %v}", test.cfg, builderMap, err, test.wantErrPrefix)
}
})
}
}
func TestRLSKey(t *testing.T) {
bm, err := MakeBuilderMap(&rlspb.RouteLookupConfig{
GrpcKeybuilders: []*rlspb.GrpcKeyBuilder{goodKeyBuilder1, goodKeyBuilder2},
})
if err != nil {
t.Fatalf("MakeBuilderMap() failed: %v", err)
}
tests := []struct {
desc string
path string
md metadata.MD
wantKM KeyMap
}{
{
// No keyBuilder is found for the provided service.
desc: "service not found in key builder map",
path: "/notFoundService/method",
md: metadata.Pairs("n1", "v1", "n2", "v2"),
wantKM: KeyMap{},
},
{
// No keyBuilder is found for the provided method.
desc: "method not found in key builder map",
path: "/gBar/notFoundMethod",
md: metadata.Pairs("n1", "v1", "n2", "v2"),
wantKM: KeyMap{},
},
{
// A keyBuilder is found, but none of the headers match.
desc: "directPathMatch-NoMatchingKey",
path: "/gBar/method1",
md: metadata.Pairs("notMatchingKey", "v1"),
wantKM: KeyMap{Map: map[string]string{}, Str: ""},
},
{
// A keyBuilder is found, and a single headers matches.
desc: "directPathMatch-SingleKey",
path: "/gBar/method1",
md: metadata.Pairs("n1", "v1"),
wantKM: KeyMap{Map: map[string]string{"k1": "v1"}, Str: "k1=v1"},
},
{
// A keyBuilder is found, and multiple headers match, but the first
// match is chosen.
desc: "directPathMatch-FirstMatchingKey",
path: "/gBar/method1",
md: metadata.Pairs("n2", "v2", "n1", "v1"),
wantKM: KeyMap{Map: map[string]string{"k1": "v1"}, Str: "k1=v1"},
},
{
// A keyBuilder is found as a wildcard match, but none of the
// headers match.
desc: "wildcardPathMatch-NoMatchingKey",
path: "/gFoobar/method1",
md: metadata.Pairs("notMatchingKey", "v1"),
wantKM: KeyMap{Map: map[string]string{}, Str: ""},
},
{
// A keyBuilder is found as a wildcard match, and a single headers
// matches.
desc: "wildcardPathMatch-SingleKey",
path: "/gFoobar/method1",
md: metadata.Pairs("n1", "v1"),
wantKM: KeyMap{Map: map[string]string{"k1": "v1"}, Str: "k1=v1"},
},
{
// A keyBuilder is found as a wildcard match, and multiple headers
// match, but the first match is chosen.
desc: "wildcardPathMatch-FirstMatchingKey",
path: "/gFoobar/method1",
md: metadata.Pairs("n2", "v2", "n1", "v1"),
wantKM: KeyMap{Map: map[string]string{"k1": "v1"}, Str: "k1=v1"},
},
{
// Multiple matchers find hits in the provided request headers.
desc: "multipleMatchers",
path: "/gFoo/method1",
md: metadata.Pairs("n2", "v2", "n1", "v1"),
wantKM: KeyMap{Map: map[string]string{"k1": "v1", "k2": "v1"}, Str: "k1=v1,k2=v1"},
},
{
// A match is found for a header which is specified multiple times.
// So, the values are joined with commas separating them.
desc: "commaSeparated",
path: "/gBar/method1",
md: metadata.Pairs("n1", "v1", "n1", "v2", "n1", "v3"),
wantKM: KeyMap{Map: map[string]string{"k1": "v1,v2,v3"}, Str: "k1=v1,v2,v3"},
},
}
for _, test := range tests {
t.Run(test.desc, func(t *testing.T) {
if gotKM := bm.RLSKey(test.md, test.path); !cmp.Equal(gotKM, test.wantKM) {
t.Errorf("RLSKey(%+v, %s) = %+v, want %+v", test.md, test.path, gotKM, test.wantKM)
}
})
}
}
func TestMapToString(t *testing.T) {
tests := []struct {
desc string
input map[string]string
wantStr string
}{
{
desc: "empty map",
input: nil,
wantStr: "",
},
{
desc: "one key",
input: map[string]string{
"k1": "v1",
},
wantStr: "k1=v1",
},
{
desc: "sorted keys",
input: map[string]string{
"k1": "v1",
"k2": "v2",
"k3": "v3",
},
wantStr: "k1=v1,k2=v2,k3=v3",
},
{
desc: "unsorted keys",
input: map[string]string{
"k3": "v3",
"k1": "v1",
"k2": "v2",
},
wantStr: "k1=v1,k2=v2,k3=v3",
},
}
for _, test := range tests {
t.Run(test.desc, func(t *testing.T) {
if gotStr := mapToString(test.input); gotStr != test.wantStr {
t.Errorf("mapToString(%v) = %s, want %s", test.input, gotStr, test.wantStr)
}
})
}
}