driver: Cache pipeline config and improve request latency (#348)

Closes #346

driver/configuration/provider_viper.go

@@ -2,10 +2,13 @@ package configuration
 
 import (
 	"bytes"
+	"encoding/binary"
 	"encoding/json"
 	"fmt"
+	"hash/crc64"
 	"net/url"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/imdario/mergo"
@@ -101,11 +104,16 @@ const (
 )
 
 type ViperProvider struct {
-	l logrus.FieldLogger
+	l            logrus.FieldLogger
+	configMutex  sync.RWMutex
+	configCachge map[uint64]json.RawMessage
 }
 
 func NewViperProvider(l logrus.FieldLogger) *ViperProvider {
-	return &ViperProvider{l: l}
+	return &ViperProvider{
+		l:            l,
+		configCachge: make(map[uint64]json.RawMessage),
+	}
 }
 
 func (v *ViperProvider) AccessRuleRepositories() []url.URL {
@@ -197,7 +205,46 @@ func (v *ViperProvider) pipelineIsEnabled(prefix, id string) bool {
 	return viperx.GetBool(v.l, fmt.Sprintf("%s.%s.enabled", prefix, id), false)
 }
 
+func (v *ViperProvider) hashPipelineConfig(prefix, id string, override json.RawMessage) (uint64, error) {
+	ts := viper.ConfigChangeAt().UnixNano()
+	b := make([]byte, 8)
+	binary.LittleEndian.PutUint64(b, uint64(ts))
+
+	slices := [][]byte{
+		[]byte(prefix),
+		[]byte(id),
+		[]byte(override),
+		[]byte(b),
+	}
+
+	var hashSlices []byte
+	for _, s := range slices {
+		hashSlices = append(hashSlices, s...)
+	}
+
+	return crc64.Checksum(hashSlices, crc64.MakeTable(crc64.ECMA)), nil
+}
+
 func (v *ViperProvider) PipelineConfig(prefix, id string, override json.RawMessage, dest interface{}) error {
+	hash, err := v.hashPipelineConfig(prefix, id, override)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	v.configMutex.RLock()
+	c, ok := v.configCachge[hash]
+	v.configMutex.RUnlock()
+
+	if ok {
+		if dest != nil {
+			if err := json.NewDecoder(bytes.NewBuffer(c)).Decode(dest); err != nil {
+				return errors.WithStack(err)
+			}
+		}
+
+		return nil
+	}
+
 	// we need to create a copy for config otherwise we will accidentally override values
 	config, err := x.Deepcopy(viperx.GetStringMapConfig(stringsx.Splitx(fmt.Sprintf("%s.%s.config", prefix, id), ".")...))
 	if err != nil {
@@ -252,6 +299,10 @@ func (v *ViperProvider) PipelineConfig(prefix, id string, override json.RawMessa
 		return errors.WithStack(result.Errors())
 	}
 
+	v.configMutex.Lock()
+	v.configCachge[hash] = marshalled
+	v.configMutex.Unlock()
+
 	return nil
 }
 

driver/configuration/provider_viper_public_test.go

@@ -48,11 +48,9 @@ func TestPipelineConfig(t *testing.T) {
 		require.NoError(t, p.PipelineConfig("authenticators", "oauth2_introspection", nil, &res))
 		assert.JSONEq(t, `{"introspection_request_headers":{},"introspection_url":"https://override/path","pre_authorization":{"client_id":"some_id","client_secret":"some_secret","enabled":true,"scope":["foo","bar"],"token_url":"https://my-website.com/oauth2/token"},"required_scope":[],"scope_strategy":"exact","target_audience":[],"trusted_issuers":[]}`, string(res), "%s", res)
 
+		// Cleanup
 		require.NoError(t, os.Setenv("AUTHENTICATORS_OAUTH2_INTROSPECTION_CONFIG_INTROSPECTION_URL", ""))
 
-		require.NoError(t, p.PipelineConfig("authenticators", "oauth2_introspection", nil, &res))
-		assert.JSONEq(t, `{"introspection_request_headers":{},"introspection_url":"https://my-website.com/oauth2/introspection","pre_authorization":{"client_id":"some_id","client_secret":"some_secret","enabled":true,"scope":["foo","bar"],"token_url":"https://my-website.com/oauth2/token"},"required_scope":[],"scope_strategy":"exact","target_audience":[],"trusted_issuers":[]}`, string(res), "%s", res)
-
 	})
 
 	t.Run("case=should fail when invalid value is used in override", func(t *testing.T) {
@@ -93,6 +91,38 @@ func TestPipelineConfig(t *testing.T) {
 	})
 }
 
+/*
+go test ./... -v -bench=. -run BenchmarkPipelineConfig -benchtime=10s
+
+v0.35.1
+594	  20119202 ns/op
+
+v0.35.2
+3048037	      3908 ns/op
+*/
+
+func BenchmarkPipelineConfig(b *testing.B) {
+	viper.Reset()
+	viperx.InitializeConfig(
+		"oathkeeper",
+		"./../../docs/",
+		logrus.New(),
+	)
+
+	err := viperx.Validate(gojsonschema.NewReferenceLoader("file://../../.schemas/config.schema.json"))
+	if err != nil {
+		viperx.LoggerWithValidationErrorFields(logrus.New(), err).Error("unable to validate")
+	}
+	require.NoError(b, err)
+
+	p := NewViperProvider(logrus.New())
+
+	for n := 0; n < b.N; n++ {
+		res := json.RawMessage{}
+		p.PipelineConfig("authenticators", "oauth2_introspection", nil, &res)
+	}
+}
+
 func TestViperProvider(t *testing.T) {
 	viper.Reset()
 	viperx.InitializeConfig(

go.mod

@@ -14,7 +14,6 @@ require (
 	github.com/go-openapi/runtime v0.19.5
 	github.com/go-openapi/strfmt v0.19.3
 	github.com/go-openapi/swag v0.19.5
-	github.com/go-openapi/validate v0.19.3
 	github.com/go-sql-driver/mysql v1.4.1
 	github.com/go-swagger/go-swagger v0.21.1-0.20200107003254-1c98855b472d
 	github.com/gobuffalo/httptest v1.0.2
@@ -36,7 +35,7 @@ require (
 	github.com/ory/herodot v0.6.2
 	github.com/ory/ladon v1.0.1
 	github.com/ory/sdk/swagutil v0.0.0-20200123152503-0d50960e70bd // indirect
-	github.com/ory/viper v1.5.6
+	github.com/ory/viper v1.5.7
 	github.com/ory/x v0.0.91
 	github.com/pborman/uuid v1.2.0
 	github.com/pelletier/go-toml v1.6.0 // indirect