Inject middlewares & server configuration of gRPC and grpc-gateway from YAML file.
This belongs to rk-boot family. We suggest use this lib with rk-boot.
In the bellow example, we will start microservice with bellow functionality and middlewares enabled via YAML.
- gRPC and grpc-gateway server
- gRPC server reflection
- Swagger UI
- CommonService
- Docs
- Prometheus Metrics (middleware)
- Logging (middleware)
- Meta (middleware)
Please refer example at example/boot/simple.
go get github.com/rookie-ninja/rk-grpc/v2show
- api/v1/greeter.proto
syntax = "proto3";
package api.v1;
option go_package = "api/v1/greeter";
service Greeter {
rpc Greeter (GreeterRequest) returns (GreeterResponse) {}
}
message GreeterRequest {
bytes msg = 1;
}
message GreeterResponse {}- api/v1/gw_mapping.yaml
type: google.api.Service
config_version: 3
# Please refer google.api.Http in https://github.com/googleapis/googleapis/blob/master/google/api/http.proto file for details.
http:
rules:
- selector: api.v1.Greeter.Greeter
get: /v1/greeter- buf.yaml
version: v1beta1
name: github.com/rk-dev/rk-boot
build:
roots:
- api- buf.gen.yaml
version: v1beta1
plugins:
# protoc-gen-go needs to be installed, generate go files based on proto files
- name: go
out: api/gen
opt:
- paths=source_relative
# protoc-gen-go-grpc needs to be installed, generate grpc go files based on proto files
- name: go-grpc
out: api/gen
opt:
- paths=source_relative
- require_unimplemented_servers=false
# protoc-gen-grpc-gateway needs to be installed, generate grpc-gateway go files based on proto files
- name: grpc-gateway
out: api/gen
opt:
- paths=source_relative
- grpc_api_configuration=api/v1/gw_mapping.yaml
# protoc-gen-openapiv2 needs to be installed, generate swagger config files based on proto files
- name: openapiv2
out: api/gen
opt:
- grpc_api_configuration=api/v1/gw_mapping.yaml2.Generate .pb.go files with buf
show
$ buf generate --path api/v1
.
├── api
│ ├── gen
│ │ └── v1
│ │ ├── greeter.pb.go
│ │ ├── greeter.pb.gw.go
│ │ ├── greeter.swagger.json
│ │ └── greeter_grpc.pb.go
│ └── v1
│ ├── greeter.proto
│ └── gw_mapping.yaml
├── boot.yaml
├── buf.gen.yaml
├── buf.yaml
├── go.mod
├── go.sum
└── main.go
show
---
grpc:
- name: greeter # Required
port: 8080 # Required
enabled: true # Required
enableReflection: true # Optional, default: false
enableRkGwOption: true # Optional, default: false
commonService:
enabled: true # Optional, default: false
docs:
enabled: true # Optional, default: false
sw:
enabled: true # Optional, default: false
prom:
enabled: true # Optional, default: false
middleware:
logging:
enabled: true # Optional, default: false
prom:
enabled: true # Optional, default: false
meta:
enabled: true # Optional, default: falseshow
// Copyright (c) 2021 rookie-ninja
//
// Use of this source code is governed by an Apache-style
// license that can be found in the LICENSE file.
package main
import (
"context"
"embed"
_ "embed"
"github.com/rookie-ninja/rk-entry/v2/entry"
"github.com/rookie-ninja/rk-grpc/v2/boot"
proto "github.com/rookie-ninja/rk-grpc/v2/example/boot/simple/api/gen/v1"
"google.golang.org/grpc"
)
//go:embed boot.yaml
var boot []byte
//go:embed api/gen/v1
var docsFS embed.FS
//go:embed api/gen/v1
var staticFS embed.FS
func init() {
rkentry.GlobalAppCtx.AddEmbedFS(rkentry.DocsEntryType, "greeter", &docsFS)
rkentry.GlobalAppCtx.AddEmbedFS(rkentry.SWEntryType, "greeter", &docsFS)
rkentry.GlobalAppCtx.AddEmbedFS(rkentry.StaticFileHandlerEntryType, "greeter", &staticFS)
}
func main() {
// Bootstrap basic entries from boot config.
rkentry.BootstrapPreloadEntryYAML(boot)
// Bootstrap grpc entry from boot config
res := rkgrpc.RegisterGrpcEntryYAML(boot)
// Get GrpcEntry
grpcEntry := res["greeter"].(*rkgrpc.GrpcEntry)
// Register gRPC server
grpcEntry.AddRegFuncGrpc(func(server *grpc.Server) {
proto.RegisterGreeterServer(server, &GreeterServer{})
})
// Register grpc-gateway func
grpcEntry.AddRegFuncGw(proto.RegisterGreeterHandlerFromEndpoint)
// Bootstrap grpc entry
grpcEntry.Bootstrap(context.Background())
// Wait for shutdown signal
rkentry.GlobalAppCtx.WaitForShutdownSig()
// Interrupt gin entry
grpcEntry.Interrupt(context.Background())
}
// GreeterServer Implementation of GreeterServer.
type GreeterServer struct{}
// Greeter Handle Greeter method.
func (server *GreeterServer) Greeter(context.Context, *proto.GreeterRequest) (*proto.GreeterResponse, error) {
return &proto.GreeterResponse{}, nil
}$ go run main.go
show
Try to test gRPC & grpc-gateway Service with curl & grpcurl
# Curl to common service
$ curl localhost:8080/rk/v1/ready
{"ready":true}Please refer sw section at Full YAML.
By default, we could access swagger UI at http://localhost:8080/sw
Please refer docs section at Full YAML.
By default, we could access docs UI at http://localhost:8080/docs
Please refer middleware.prom section at Full YAML.
By default, we could access prometheus client at http://localhost:8080/metrics
Please refer middleware.logging section at Full YAML.
By default, we enable zap logger and event logger with encoding type of [console]. Encoding type of [json] and [flatten] is also supported.
2021-12-28T05:36:21.561+0800 INFO boot/grpc_entry.go:1515 Bootstrap grpcEntry {"eventId": "db2c977c-e0ff-4b21-bc0d-5966f1cad093", "entryName": "greeter"}
------------------------------------------------------------------------
endTime=2021-12-28T05:36:21.563575+08:00
startTime=2021-12-28T05:36:21.561362+08:00
elapsedNano=2213846
timezone=CST
ids={"eventId":"db2c977c-e0ff-4b21-bc0d-5966f1cad093"}
app={"appName":"rk","appVersion":"","entryName":"greeter","entryType":"GrpcEntry"}
env={"arch":"amd64","az":"*","domain":"*","hostname":"lark.local","localIP":"10.8.0.2","os":"darwin","realm":"*","region":"*"}
payloads={"commonServiceEnabled":true,"commonServicePathPrefix":"/rk/v1/","grpcPort":8080,"gwPort":8080,"promEnabled":true,"promPath":"/metrics","promPort":8080,"swEnabled":true,"swPath":"/sw/","tvEnabled":true,"tvPath":"/rk/v1/tv/"}
error={}
counters={}
pairs={}
timing={}
remoteAddr=localhost
operation=Bootstrap
resCode=OK
eventStatus=Ended
EOEPlease refer meta section at Full YAML.
By default, we will send back some metadata to client with headers.
$ curl -vs localhost:8080/rk/v1/ready
...
< HTTP/1.1 200 OK
< Content-Type: application/json
< X-Request-Id: 7e4f5ac5-3369-485f-89f7-55551cc4a9a1
< X-Rk-App-Name: rk
< X-Rk-App-Unix-Time: 2021-12-28T05:39:50.508328+08:00
< X-Rk-App-Version:
< X-Rk-Received-Time: 2021-12-28T05:39:50.508328+08:00
< Date: Mon, 27 Dec 2021 21:39:50 GMT
...We registered /v1/greeter API in grpc-gateway server and let's validate it!
$ curl -vs localhost:8080/v1/greeter
* Trying ::1...
* TCP_NODELAY set
* Connection failed
* connect to ::1 port 8080 failed: Connection refused
* Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 8080 (#0)
> GET /v1/greeter HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/7.64.1
> Accept: */*
>
< HTTP/1.1 200 OK
< Content-Type: application/json
< X-Request-Id: 07b0fbf6-cebf-40ac-84a2-533bbd4b8958
< X-Rk-App-Name: rk
< X-Rk-App-Unix-Time: 2021-12-28T05:41:04.653652+08:00
< X-Rk-App-Version:
< X-Rk-Received-Time: 2021-12-28T05:41:04.653652+08:00
< Date: Mon, 27 Dec 2021 21:41:04 GMT
< Content-Length: 2
<
* Connection #0 to host localhost left intact
{}We registered api.v1.Greeter.Greeter API in gRPC server and let's validate it!
$ grpcurl -plaintext localhost:8080 api.v1.Greeter.Greeter
{}Bellow logs would be printed in stdout.
The first block of log is from grpc-gateway request.
The second block of log is from gRPC request.
------------------------------------------------------------------------
endTime=2021-12-28T05:45:52.986041+08:00
startTime=2021-12-28T05:45:52.985956+08:00
elapsedNano=85065
timezone=CST
ids={"eventId":"88362f69-7eda-4f03-bdbe-7ef667d06bac","requestId":"88362f69-7eda-4f03-bdbe-7ef667d06bac"}
app={"appName":"rk","appVersion":"","entryName":"greeter","entryType":"GrpcEntry"}
env={"arch":"amd64","az":"*","domain":"*","hostname":"lark.local","localIP":"10.8.0.2","os":"darwin","realm":"*","region":"*"}
payloads={"grpcMethod":"Greeter","grpcService":"api.v1.Greeter","grpcType":"unaryServer","gwMethod":"GET","gwPath":"/v1/greeter","gwScheme":"http","gwUserAgent":"curl/7.64.1"}
error={}
counters={}
pairs={}
timing={}
remoteAddr=127.0.0.1:61520
operation=/api.v1.Greeter/Greeter
resCode=OK
eventStatus=Ended
EOE
------------------------------------------------------------------------
endTime=2021-12-28T05:44:45.686734+08:00
startTime=2021-12-28T05:44:45.686592+08:00
elapsedNano=141716
timezone=CST
ids={"eventId":"7765862c-9e83-443a-a6e5-bb28f17f8ea0","requestId":"7765862c-9e83-443a-a6e5-bb28f17f8ea0"}
app={"appName":"rk","appVersion":"","entryName":"greeter","entryType":"GrpcEntry"}
env={"arch":"amd64","az":"*","domain":"*","hostname":"lark.local","localIP":"10.8.0.2","os":"darwin","realm":"*","region":"*"}
payloads={"grpcMethod":"Greeter","grpcService":"api.v1.Greeter","grpcType":"unaryServer","gwMethod":"","gwPath":"","gwScheme":"","gwUserAgent":""}
error={}
counters={}
pairs={}
timing={}
remoteAddr=127.0.0.1:57149
operation=/api.v1.Greeter/Greeter
resCode=OK
eventStatus=Ended
EOE
Prometheus client will automatically register into grpc-gateway instance at /metrics.
Access http://localhost:8080/metrics
User can enable anyone of those as needed! No mandatory binding!
| Instance | Description |
|---|---|
| gRPC | gRPC defined with protocol buffer. |
| gRPC proxy | Proxy gRPC request to another gRPC server. |
| grpc-gateway | grpc-gateway service with same port. |
| grpc-gateway options | Well defined grpc-gateway options. |
| Config | Configure spf13/viper as config instance and reference it from YAML |
| Logger | Configure uber-go/zap logger configuration and reference it from YAML |
| Event | Configure logging of RPC with rk-query and reference it from YAML |
| Cert | Fetch TLS/SSL certificates from remote datastore like ETCD and start microservice. |
| Prometheus | Start prometheus client at client side and push metrics to pushgateway as needed. |
| Swagger | Builtin swagger UI handler. |
| Docs | Builtin RapiDoc instance which can be used to replace swagger and RK TV. |
| CommonService | List of common APIs. |
| StaticFileHandler | A Web UI shows files could be downloaded from server, currently support source of local and embed.FS. |
| PProf | PProf web UI. |
| gRPC Web | gRPC Web |
All middlewares could be configured via YAML or Code.
User can enable anyone of those as needed! No mandatory binding!
| Middleware | Description |
|---|---|
| Metrics | Collect RPC metrics and export to prometheus client. |
| Log | Log every RPC requests as event with rk-query. |
| Trace | Collect RPC trace and export it to stdout, file or jaeger with open-telemetry/opentelemetry-go. |
| Panic | Recover from panic for RPC requests and log it. |
| Meta | Send micsroservice metadata as header to client. |
| Auth | Support [Basic Auth] and [API Key] authorization types. |
| RateLimit | Limiting RPC rate globally or per path. |
| Timeout | Timing out request by configuration. |
| CORS | Server side CORS validation. |
| JWT | Server side JWT validation. |
| Secure | Server side secure validation. |
| CSRF | Server side csrf validation. |
User can start multiple gRPC and grpc-gateway instances at the same time. Please make sure use different port and name.
show
---
#app:
# name: my-app # Optional, default: "rk-app"
# version: "v1.0.0" # Optional, default: "v0.0.0"
# description: "this is description" # Optional, default: ""
# keywords: ["rk", "golang"] # Optional, default: []
# homeUrl: "http://example.com" # Optional, default: ""
# docsUrl: ["http://example.com"] # Optional, default: []
# maintainers: ["rk-dev"] # Optional, default: []
#logger:
# - name: my-logger # Required
# description: "Description of entry" # Optional
# domain: "*" # Optional, default: "*"
# default: false # Optional, default: false, use as default logger entry
# zap: # Optional
# level: info # Optional, default: info
# development: true # Optional, default: true
# disableCaller: false # Optional, default: false
# disableStacktrace: true # Optional, default: true
# encoding: console # Optional, default: console
# outputPaths: ["stdout"] # Optional, default: [stdout]
# errorOutputPaths: ["stderr"] # Optional, default: [stderr]
# encoderConfig: # Optional
# timeKey: "ts" # Optional, default: ts
# levelKey: "level" # Optional, default: level
# nameKey: "logger" # Optional, default: logger
# callerKey: "caller" # Optional, default: caller
# messageKey: "msg" # Optional, default: msg
# stacktraceKey: "stacktrace" # Optional, default: stacktrace
# skipLineEnding: false # Optional, default: false
# lineEnding: "\n" # Optional, default: \n
# consoleSeparator: "\t" # Optional, default: \t
# sampling: # Optional, default: nil
# initial: 0 # Optional, default: 0
# thereafter: 0 # Optional, default: 0
# initialFields: # Optional, default: empty map
# key: value
# lumberjack: # Optional, default: nil
# filename:
# maxsize: 1024 # Optional, suggested: 1024 (MB)
# maxage: 7 # Optional, suggested: 7 (day)
# maxbackups: 3 # Optional, suggested: 3 (day)
# localtime: true # Optional, suggested: true
# compress: true # Optional, suggested: true
# loki:
# enabled: true # Optional, default: false
# addr: localhost:3100 # Optional, default: localhost:3100
# path: /loki/api/v1/push # Optional, default: /loki/api/v1/push
# username: "" # Optional, default: ""
# password: "" # Optional, default: ""
# maxBatchWaitMs: 3000 # Optional, default: 3000
# maxBatchSize: 1000 # Optional, default: 1000
# insecureSkipVerify: false # Optional, default: false
# labels: # Optional, default: empty map
# my_label_key: my_label_value
#event:
# - name: my-event # Required
# description: "Description of entry" # Optional
# domain: "*" # Optional, default: "*"
# encoding: console # Optional, default: console
# default: false # Optional, default: false, use as default event entry
# outputPaths: ["stdout"] # Optional, default: [stdout]
# lumberjack: # Optional, default: nil
# filename:
# maxsize: 1024 # Optional, suggested: 1024 (MB)
# maxage: 7 # Optional, suggested: 7 (day)
# maxbackups: 3 # Optional, suggested: 3 (day)
# localtime: true # Optional, suggested: true
# compress: true # Optional, suggested: true
# loki:
# enabled: true # Optional, default: false
# addr: localhost:3100 # Optional, default: localhost:3100
# path: /loki/api/v1/push # Optional, default: /loki/api/v1/push
# username: "" # Optional, default: ""
# password: "" # Optional, default: ""
# maxBatchWaitMs: 3000 # Optional, default: 3000
# maxBatchSize: 1000 # Optional, default: 1000
# insecureSkipVerify: false # Optional, default: false
# labels: # Optional, default: empty map
# my_label_key: my_label_value
#cert:
# - name: my-cert # Required
# description: "Description of entry" # Optional, default: ""
# domain: "*" # Optional, default: "*"
# caPath: "certs/ca.pem" # Optional, default: ""
# certPemPath: "certs/server-cert.pem" # Optional, default: ""
# keyPemPath: "certs/server-key.pem" # Optional, default: ""
#config:
# - name: my-config # Required
# description: "Description of entry" # Optional, default: ""
# domain: "*" # Optional, default: "*"
## path: "config/config.yaml" # Optional
# envPrefix: "" # Optional, default: ""
# content: # Optional, defualt: empty map
# key: value
grpc:
- name: greeter # Required
enabled: true # Required
port: 8080 # Required
# description: "greeter server" # Optional, default: ""
# enableReflection: true # Optional, default: false
# enableRkGwOption: true # Optional, default: false
# grpcWeb:
# enabled: true
# cors:
# allowOrigins: [] # Optional, default: [*]
# websocket:
# enabled: true # Optional, default: disable websocket
# pingIntervalMs: 10 # Optional, default: disable ping
# messageReadLimitBytes: 32769 # Optional, default: 32769
# gwOption: # Optional, default: nil
# marshal: # Optional, default: nil
# multiline: false # Optional, default: false
# emitUnpopulated: false # Optional, default: false
# indent: "" # Optional, default: false
# allowPartial: false # Optional, default: false
# useProtoNames: false # Optional, default: false
# useEnumNumbers: false # Optional, default: false
# unmarshal: # Optional, default: nil
# allowPartial: false # Optional, default: false
# discardUnknown: false # Optional, default: false
# noRecvMsgSizeLimit: true # Optional, default: false
# certEntry: my-cert # Optional, default: "", reference of cert entry declared above
# loggerEntry: my-logger # Optional, default: "", reference of cert entry declared above, STDOUT will be used if missing
# eventEntry: my-event # Optional, default: "", reference of cert entry declared above, STDOUT will be used if missing
# sw:
# enabled: true # Optional, default: false
# path: "sw" # Optional, default: "sw"
# jsonPath: "" # Optional
# headers: ["sw:rk"] # Optional, default: []
# docs:
# enabled: true # Optional, default: false
# path: "docs" # Optional, default: "docs"
# specPath: "" # Optional
# headers: ["sw:rk"] # Optional, default: []
# style: # Optional
# theme: "light" # Optional, default: "light"
# debug: false # Optional, default: false
# commonService:
# enabled: true # Optional, default: false
# static:
# enabled: true # Optional, default: false
# path: "/static" # Optional, default: /static
# sourceType: local # Required, options: pkger, local
# sourcePath: "." # Required, full path of source directory
# pprof:
# enabled: true # Optional, default: false
# path: "/pprof" # Optional, default: /pprof
# prom:
# enabled: true # Optional, default: false
# path: "" # Optional, default: "metrics"
# pusher:
# enabled: false # Optional, default: false
# jobName: "greeter-pusher" # Required
# remoteAddress: "localhost:9091" # Required
# basicAuth: "user:pass" # Optional, default: ""
# intervalMs: 10000 # Optional, default: 1000
# certEntry: my-cert # Optional, default: "", reference of cert entry declared above
# middleware:
# ignore: [""] # Optional, default: []
# errorModel: google # Optional, default: google, [amazon, google] are supported options
# logging:
# enabled: true # Optional, default: false
# ignore: [""] # Optional, default: []
# loggerEncoding: "console" # Optional, default: "console"
# loggerOutputPaths: ["logs/app.log"] # Optional, default: ["stdout"]
# eventEncoding: "console" # Optional, default: "console"
# eventOutputPaths: ["logs/event.log"] # Optional, default: ["stdout"]
# prom:
# enabled: true # Optional, default: false
# ignore: [""] # Optional, default: []
# auth:
# enabled: true # Optional, default: false
# ignore: [""] # Optional, default: []
# basic:
# - "user:pass" # Optional, default: []
# apiKey:
# - "keys" # Optional, default: []
# meta:
# enabled: true # Optional, default: false
# ignore: [""] # Optional, default: []
# prefix: "rk" # Optional, default: "rk"
# trace:
# enabled: true # Optional, default: false
# ignore: [""] # Optional, default: []
# exporter: # Optional, default will create a stdout exporter
# file:
# enabled: true # Optional, default: false
# outputPath: "logs/trace.log" # Optional, default: stdout
# jaeger:
# agent:
# enabled: false # Optional, default: false
# host: "" # Optional, default: localhost
# port: 0 # Optional, default: 6831
# collector:
# enabled: true # Optional, default: false
# endpoint: "" # Optional, default: http://localhost:14268/api/traces
# username: "" # Optional, default: ""
# password: "" # Optional, default: ""
# rateLimit:
# enabled: false # Optional, default: false
# ignore: [""] # Optional, default: []
# algorithm: "leakyBucket" # Optional, default: "tokenBucket"
# reqPerSec: 100 # Optional, default: 1000000
# paths:
# - path: "/rk/v1/healthy" # Optional, default: ""
# reqPerSec: 0 # Optional, default: 1000000
# timeout:
# enabled: false # Optional, default: false
# ignore: [""] # Optional, default: []
# timeoutMs: 5000 # Optional, default: 5000
# paths:
# - path: "/rk/v1/healthy" # Optional, default: ""
# timeoutMs: 1000 # Optional, default: 5000
# jwt:
# enabled: true # Optional, default: false
# ignore: [ "" ] # Optional, default: []
# signerEntry: "" # Optional, default: ""
# skipVerify: false # Optional, default: false
# symmetric: # Optional
# algorithm: "" # Required, default: ""
# token: "" # Optional, default: ""
# tokenPath: "" # Optional, default: ""
# asymmetric: # Optional
# algorithm: "" # Required, default: ""
# privateKey: "" # Optional, default: ""
# privateKeyPath: "" # Optional, default: ""
# publicKey: "" # Optional, default: ""
# publicKeyPath: "" # Optional, default: ""
# tokenLookup: "header:<name>" # Optional, default: "header:Authorization"
# authScheme: "Bearer" # Optional, default: "Bearer"
# secure:
# enabled: true # Optional, default: false
# ignore: [""] # Optional, default: []
# xssProtection: "" # Optional, default: "1; mode=block"
# contentTypeNosniff: "" # Optional, default: nosniff
# xFrameOptions: "" # Optional, default: SAMEORIGIN
# hstsMaxAge: 0 # Optional, default: 0
# hstsExcludeSubdomains: false # Optional, default: false
# hstsPreloadEnabled: false # Optional, default: false
# contentSecurityPolicy: "" # Optional, default: ""
# cspReportOnly: false # Optional, default: false
# referrerPolicy: "" # Optional, default: ""
# csrf:
# enabled: true # Optional, default: false
# ignore: [""] # Optional, default: []
# tokenLength: 32 # Optional, default: 32
# tokenLookup: "header:X-CSRF-Token" # Optional, default: "header:X-CSRF-Token"
# cookieName: "_csrf" # Optional, default: _csrf
# cookieDomain: "" # Optional, default: ""
# cookiePath: "" # Optional, default: ""
# cookieMaxAge: 86400 # Optional, default: 86400
# cookieHttpOnly: false # Optional, default: false
# cookieSameSite: "default" # Optional, default: "default", options: lax, strict, none, default
# gzip:
# enabled: true # Optional, default: false
# ignore: [""] # Optional, default: []
# level: bestSpeed # Optional, options: [noCompression, bestSpeed， bestCompression, defaultCompression, huffmanOnly]
# cors:
# enabled: true # Optional, default: false
# ignore: [""] # Optional, default: []
# allowOrigins: # Optional, default: []
# - "http://localhost:*" # Optional, default: *
# allowCredentials: false # Optional, default: false
# allowHeaders: [] # Optional, default: []
# allowMethods: [] # Optional, default: []
# exposeHeaders: [] # Optional, default: []
# maxAge: 0 # Optional, default: 0Simply run make all to validate your changes. Or run codes in example/ folder.
- make all
Run unit-test, golangci-lint, doctoc and gofmt.
- make buf
Run unit test with make test command.
Github workflow will automatically run unit test and golangci-lint for testing and lint validation.
We encourage and support an active, healthy community of contributors; including you! Details are in the contribution guide and the code of conduct. The rk maintainers keep an eye on issues and pull requests, but you can also report any negative conduct to lark@rkdev.info.
Released under the Apache 2.0 License.