明天跟大家分享一个小教程，如何本人入手写一个新组件，并加载到Dapr runtime。
后期筹备
- 对于Dapr runtime的启动过程，如何加载和实例化组件能够参考之前写的文章Dapr runtime 启动过程
- Dapr开发环境配置，能够参考Dapr 开发环境配置
开始编码
克隆Dapr和 component-contrib
cd $GOPATH/src# Clone daprmkdir -p github.com/dapr/daprgit clone https://github.com/dapr/dapr.git github.com/dapr/dapr# Clone component-contribmkdir -p github.com/dapr/components-contribgit clone https://github.com/dapr/components-contrib.git github.com/dapr/components-contrib编写组件
假如，咱们组件名字叫：Mytest
首先在component-contrib我的项目下，创立mytest包。
- 在mytest文件夹创立接口束缚文件：
github.com/dapr/components-contrib/mytest/mytest.go
mytest组件提供两个办法，Init和Info
package mytesttype Mytest interface { // Init this component. Init(metadata Metadata) // Info show method Info(info string)}metadata.go：接管组件配置文件YAML中定义的Metadata字段
package mytesttype Metadata struct { Properties map[string]string `json:"properties"`}3.为mytest组件提供两种实现形式：demof和demos
在mytest包里创立demof包和demos包，别离在demof.go和demos.go实现Mytest组件demof.go
package demofimport ( "github.com/dapr/components-contrib/mytest" "github.com/dapr/kit/logger")type Demof struct { logger logger.Logger}func NewDemof(logger logger.Logger) *Demof { d := &Demof{ logger: logger, } return d}func (d *Demof) Init(metadata mytest.Metadata) { d.logger.Info(metadata)}func (d *Demof) Info(info string) { d.logger.Info("this is Demof, I received %s", info)}demos.go
package demosimport ( "github.com/dapr/components-contrib/mytest" "github.com/dapr/kit/logger")type Demos struct { logger logger.Logger}func NewDemos(logger logger.Logger) *Demos { d := &Demos{ logger: logger, } return d}func (d *Demos) Init(metadata mytest.Metadata) { d.logger.Info(metadata)}func (d *Demos) Info(info string) { d.logger.Info("this is Demos, I received %s", info)}至此Mytest组件曾经具备了能够执行的所有因素，目录解构如下
component-contrib |_mytest |_demof |_demof.go |_demos |_demos.go metadata.go mytest.go将Mytest组件注册到Dapr runtime
- 实现Mytest组件注册接口
github.com/dapr/dapr/pkg/components/mytest/registry.go
package mytestimport ( "strings" "github.com/pkg/errors" "github.com/dapr/components-contrib/mytest" "github.com/dapr/dapr/pkg/components")type Mytest struct { Name string FactoryMethod func() mytest.Mytest}func New(name string, factoryMethod func() mytest.Mytest) Mytest { return Mytest{ Name: name, FactoryMethod: factoryMethod, }}type Registry interface { Register(components ...Mytest) Create(name, version string) (mytest.Mytest, error)}type mytestRegistry struct { mytests map[string]func() mytest.Mytest}func NewRegistry() Registry { return &mytestRegistry{ mytests: map[string]func() mytest.Mytest{}, }}func (t *mytestRegistry) Register(components ...Mytest) { for _, component := range components { t.mytests[createFullName(component.Name)] = component.FactoryMethod }}func (t *mytestRegistry) Create(name, version string) (mytest.Mytest, error) { if method, ok := t.getMytest(name, version); ok { return method(), nil } return nil, errors.Errorf("couldn't find Mytest %s/%s", name, version)}func (t *mytestRegistry) getMytest(name, version string) (func() mytest.Mytest, bool) { nameLower := strings.ToLower(name) versionLower := strings.ToLower(version) mytestFn, ok := t.mytests[nameLower+"/"+versionLower] if ok { return mytestFn, true } if components.IsInitialVersion(versionLower) { mytestFn, ok = t.mytests[nameLower] } return mytestFn, ok}func createFullName(name string) string { return strings.ToLower("mytest." + name)}2.更新runtime 组件发现和注册机制github.com/dapr/dapr/pkg/runtime/options.go
扩大runtimeOpts
import("github.com/dapr/dapr/pkg/components/mytest")runtimeOpts struct { ... mytests []mytest.Mytest}增加runtime组件注册函数
func WithMytests(mytests ...mytest.Mytest) Option { return func(o *runtimeOpts) { o.mytests = append(o.mytests, mytests...) }}更新runtime启动流程，注册Mytest组件github.com/dapr/dapr/pkg/runtime/runtime.go
import(...."github.com/dapr/components-contrib/mytest" mytest_loader "github.com/dapr/dapr/pkg/components/mytest")...//更新变量申明const ( mytestComponent ComponentCategory = "mytest")var componentCategoriesNeedProcess = []ComponentCategory{ ... mytestComponent,}...// 扩大 DaprRuntime components of the runtime.type DaprRuntime struct { ... mytestRegistry mytest_loader.Registry mytests map[string]mytest.Mytest}// NewDaprRuntime returns a new runtime with the given runtime config and global config.func NewDaprRuntime(runtimeConfig *Config, globalConfig *config.Configuration, accessControlList *config.AccessControlList, resiliencyProvider resiliency.Provider) *DaprRuntime { ctx, cancel := context.WithCancel(context.Background()) return &DaprRuntime{ ... mytestRegistry: mytest_loader.NewRegistry(), mytests: map[string]mytest.Mytest{}, }}...//初始化runtimefunc (a *DaprRuntime) initRuntime(opts *runtimeOpts) error { ... a.mytestRegistry.Register(opts.mytests...) ...}//本示例仅以http api接口为例func (a *DaprRuntime) startHTTPServer(port int, publicPort *int, profilePort int, allowedOrigins string, pipeline http_middleware.Pipeline) error { a.daprHTTPAPI = http.NewAPI(a.runtimeConfig.ID, a.appChannel, a.directMessaging, a.getComponents, a.resiliency, a.stateStores, a.lockStores, a.secretStores, a.secretsConfiguration, a.configurationStores, a.getPublishAdapter(), a.actor, a.sendToOutputBinding, a.globalConfig.Spec.TracingSpec, a.ShutdownWithWait, a.getComponentsCapabilitesMap, a.mytests, )...}//runtime初始化过程从components目录 发现并初始化组件func (a *DaprRuntime) doProcessOneComponent(category ComponentCategory, comp components_v1alpha1.Component) error { switch category { ... case mytestComponent: return a.initMytest(comp) } return nil}func (a *DaprRuntime) initMytest(c components_v1alpha1.Component) error { mytestIns, err := a.mytestRegistry.Create(c.Spec.Type, c.Spec.Version) if err != nil { log.Errorf("error create component %s: %s", c.ObjectMeta.Name, err) } a.mytests[c.ObjectMeta.Name] = mytestIns properties := a.convertMetadataItemsToProperties(c.Spec.Metadata) log.Debug("properties is ", properties) mytestIns.Init(mytest.Metadata{ Properties: properties, }) return err}实现Dapr http api调用接口
github.com/dapr/dapr/pkg/http/api.go
import ("github.com/dapr/components-contrib/mytest")type api struct { .... mytests map[string]mytest.Mytest}const ( ... mytestParam = "mytestName")// NewAPI returns a new API.func NewAPI( ... mytests map[string]mytest.Mytest,) API { ... api := &api{ ... mytests: mytests, } ... api.endpoints = append(api.endpoints, api.constructMytestEndpoints()...) return api}/** * regist Mytest component api */func (a *api) constructMytestEndpoints() []Endpoint { return []Endpoint{ { Methods: []string{fasthttp.MethodGet, fasthttp.MethodPost}, Route: "mytest/{mytestName}/info", Version: apiVersionV1, Handler: a.onMytestInfo, }, }}/** * switch Mytest component instance */func (a *api) getMytestWithRequestValidation(reqCtx *fasthttp.RequestCtx) (mytest.Mytest, string, error) { if a.mytests == nil || len(a.mytests) == 0 { msg := NewErrorResponse("ERR_MYTEST_NOT_CONFIGURED", messages.ErrMytestNotFound) respond(reqCtx, withError(fasthttp.StatusInternalServerError, msg)) log.Debug(msg) return nil, "", errors.New(msg.Message) } mytestName := a.getMytestName(reqCtx) if a.mytests[mytestName] == nil { msg := NewErrorResponse("ERR_MYTEST_NOT_CONFIGURED", fmt.Sprintf(messages.ErrMytestNotFound, mytestName)) respond(reqCtx, withError(fasthttp.StatusBadRequest, msg)) log.Debug(msg) return nil, "", errors.New(msg.Message) } return a.mytests[mytestName], mytestName, nil}func (a *api) getMytestName(reqCtx *fasthttp.RequestCtx) string { return reqCtx.UserValue(mytestParam).(string)}func (a *api) onMytestInfo(reqCtx *fasthttp.RequestCtx) { log.Debug("calling mytest components") mytestInstance, _, err := a.getMytestWithRequestValidation(reqCtx) if err != nil { log.Debug(err) return } mytestInstance.Info() respond(reqCtx, withEmpty())}Dapr runtime初始化入口
github.com/dapr/dapr/cmd/daprd/main.go
import ( //mytest demo "github.com/dapr/components-contrib/mytest" mytest_demof "github.com/dapr/components-contrib/mytest/demof" mytest_demos "github.com/dapr/components-contrib/mytest/demos" mytest_loader "github.com/dapr/dapr/pkg/components/mytest")...runtime.WithSecretStores(... runtime.WithMytests( mytest_loader.New("demof", func() mytest.Mytest { return mytest_demof.NewDemof(logContrib) }), mytest_loader.New("demos", func() mytest.Mytest { return mytest_demos.NewDemos(logContrib) }), ),...)....在component目录中增加mytest.yaml 配置文件
默认是在.dapr/components目录
apiVersion: dapr.io/v1alpha1kind: Componentmetadata: name: demofspec: type: mytest.demof version: v1 metadata: - name: mName value: mValue编译并运行Dapr
go mod edit -replace github.com/dapr/components-contrib=../components-contribgo mod tidymake DEBUG=1 build# Back up the current daprdcp ~/.dapr/bin/daprd ~/.dapr/bin/daprd.bakcp ./dist/darwin_amd64/debug/daprd ~/.dapr/bindapr run --app-id myapp --dapr-http-port 3500 --log-level debug察看Dapr启动日志
DEBU[0000] loading component. name: demof, type: mytest.demof/v1 app_id=myapp instance=MacBook-Pro-3.local scope=dapr.runtime type=log ver=edgeINFO[0000] component loaded. name: demof, type: mytest.demof/v1 app_id=myapp instance=MacBook-Pro-3.local scope=dapr.runtime type=log ver=edgeINFO[0000] {map[mName:mValue]} app_id=myapp instance=MacBook-Pro-3.local scope=dapr.contrib type=log ver=edgedemof组件曾经加载胜利，接下来应用http api接口尝试调用demof info接口
curl http://localhost:3500/v1.0/mytest/demof/info日志记录到了咱们在组件中打印的信息
INFO[0126] this is Demof, I'm working app_id=myapp instance=MacBook-Pro-3.local scope=dapr.contrib type=log ver=edge批改一下mytest.yaml 配置文件，实例化demos
apiVersion: dapr.io/v1alpha1kind: Componentmetadata: name: demosspec: type: mytest.demos version: v1 metadata: - name: mName value: mValue尝试调用demos info接口
curl http://localhost:3500/v1.0/mytest/demos/infoINFO[0058] this is Demos, I'm working app_id=myapp instance=MacBook-Pro-3.local scope=dapr.contrib type=log ver=edge组件失常工作。
以上示例代码曾经放在github上
https://github.com/RcXu/dapr.git
https://github.com/RcXu/components-contrib.git
分支名为：dev-demo
多谢浏览，敬请斧正！