内容纲要
服务调用API的Proto定义
InvokeService的定义
Service Invoken API 定义在 proto文件 dapr/proto/runtime/v1/dapr.proto 中：
service Dapr {
// Invokes a method on a remote Dapr app.
rpc InvokeService(InvokeServiceRequest) returns (common.v1.InvokeResponse) {}
...
}InvokeServiceRequest 包含一个被调用服务的ID，和通用的 InvokeRequest：
// InvokeServiceRequest represents the request message for Service invocation.
message InvokeServiceRequest {
// Required. Callee's app id.
string id = 1;
// Required. message which will be delivered to callee.
common.v1.InvokeRequest message = 3;
}AppCallback的定义
AppCallback API 定义在 proto文件 dapr/proto/runtime/v1/appcallback.proto 中：
service AppCallback {
// Invokes service method with InvokeRequest.
rpc OnInvoke (common.v1.InvokeRequest) returns (common.v1.InvokeResponse) {}
...
}Invoke的通用定义
Invoke的通用定义在 proto文件 dapr/proto/common/v1/common.proto 中。
InvokeRequest是用来携带数据调用方法的消息，这个消息在Dapr gRPC服务的InvokeService和AppCallback gRPC服务的OnInvoke中使用：
// InvokeRequest is the message to invoke a method with the data.
// This message is used in InvokeService of Dapr gRPC Service and OnInvoke
// of AppCallback gRPC service.
message InvokeRequest {
// Required. method is a method name which will be invoked by caller.
string method = 1;
// Required. Bytes value or Protobuf message which caller sent.
// Dapr treats Any.value as bytes type if Any.type_url is unset.
google.protobuf.Any data = 2;
// The type of data content.
//
// This field is required if data delivers http request body
// Otherwise, this is optional.
string content_type = 3;
// HTTP specific fields if request conveys http-compatible request.
//
// This field is required for http-compatible request. Otherwise,
// this field is optional.
HTTPExtension http_extension = 4;
}InvokeResponse是包括应用程序回调的数据和内容类型的响应消息，该消息在Dapr gRPC服务的InvokeService方法和AppCallback gRPC服务的OnInvoke方法中使用：
// InvokeResponse is the response message inclduing data and its content type
// from app callback.
// This message is used in InvokeService of Dapr gRPC Service and OnInvoke
// of AppCallback gRPC service.
message InvokeResponse {
// Required. The content body of InvokeService response.
google.protobuf.Any data = 1;
// Required. The type of data content.
string content_type = 2;
}相关的消息定义
HTTPExtension 消息的定义：
// 当Dapr运行时传递HTTP内容时，HTTPExtension包括HTTP verb和querystring。
//
// For example, when callers calls http invoke api
// POST http://localhost:3500/v1.0/invoke/<app_id>/method/<method>?query1=value1&query2=value2
//
// Dapr runtime will parse POST as a verb and extract querystring to quersytring map.
message HTTPExtension {
// Type of HTTP 1.1 Methods
// RFC 7231: https://tools.ietf.org/html/rfc7231#page-24
enum Verb {
NONE = 0;
GET = 1;
HEAD = 2;
POST = 3;
PUT = 4;
DELETE = 5;
CONNECT = 6;
OPTIONS = 7;
TRACE = 8;
}
// Required. HTTP verb.
Verb verb = 1;
// querystring includes HTTP querystring.
map<string, string> querystring = 2;
}
Any消息的定义：
message Any {
string type_url = 1;
// Must be a valid serialized protocol buffer of the above specified type.
bytes value = 2;
}服务调用API的golang生成代码
服务调用API的golang生成代码
从proto api定义文件生成的golang代码，被存放在dapr项目的 pkg/proto/ 目录下。
grpc服务定义
DaprServer 是 dapr 服务的服务器端API定义，包含 InvokeService方法：
// DaprServer is the server API for Dapr service.
type DaprServer interface {
// Invokes a method on a remote Dapr app.
InvokeService(context.Context, *InvokeServiceRequest) (*v1.InvokeResponse, error)
......
}AppCallbackServer 是 AppCallback 服务的服务器端API定义，包含 OnInvoke 方法：
// AppCallbackServer is the server API for AppCallback service.
type AppCallbackServer interface {
// Invokes service method with InvokeRequest.
OnInvoke(context.Context, *v1.InvokeRequest) (*v1.InvokeResponse, error)
......
}InvokeServiceRequest的定义
type InvokeServiceRequest struct {
// Required. Callee's app id.
Id string `protobuf:"bytes,1,opt,name=id,proto3" json:"id,omitempty"`
// Required. message which will be delivered to callee.
Message *v1.InvokeRequest `protobuf:"bytes,3,opt,name=message,proto3" json:"message,omitempty"`
XXX_NoUnkeyedLiteral struct{} `json:"-"`
XXX_unrecognized []byte `json:"-"`
XXX_sizecache int32 `json:"-"`
}InvokeRequest的定义
type InvokeRequest struct {
// Required. method is a method name which will be invoked by caller.
Method string `protobuf:"bytes,1,opt,name=method,proto3" json:"method,omitempty"`
// Required. Bytes value or Protobuf message which caller sent.
// Dapr treats Any.value as bytes type if Any.type_url is unset.
Data *any.Any `protobuf:"bytes,2,opt,name=data,proto3" json:"data,omitempty"`
// The type of data content.
//
// This field is required if data delivers http request body
// Otherwise, this is optional.
ContentType string `protobuf:"bytes,3,opt,name=content_type,json=contentType,proto3" json:"content_type,omitempty"`
// HTTP specific fields if request conveys http-compatible request.
//
// This field is required for http-compatible request. Otherwise,
// this field is optional.
HttpExtension *HTTPExtension `protobuf:"bytes,4,opt,name=http_extension,json=httpExtension,proto3" json:"http_extension,omitempty"`
XXX_NoUnkeyedLiteral struct{} `json:"-"`
XXX_unrecognized []byte `json:"-"`
XXX_sizecache int32 `json:"-"`
}
InvokeResponse的定义
type InvokeResponse struct {
// Required. The content body of InvokeService response.
Data *any.Any `protobuf:"bytes,1,opt,name=data,proto3" json:"data,omitempty"`
// Required. The type of data content.
ContentType string `protobuf:"bytes,2,opt,name=content_type,json=contentType,proto3" json:"content_type,omitempty"`
XXX_NoUnkeyedLiteral struct{} `json:"-"`
XXX_unrecognized []byte `json:"-"`
XXX_sizecache int32 `json:"-"`
}备注：只是在proto定义的字段上增加了一些 XXX_ 字段。
服务调用的go client定义
Dapr服务调用的go client定义
DaprClient
// DaprClient is the client API for Dapr service.
//
// For semantics around ctx use and closing/ending streaming RPCs, please refer to https://godoc.org/google.golang.org/grpc#ClientConn.NewStream.
type DaprClient interface {
// Invokes a method on a remote Dapr app.
InvokeService(ctx context.Context, in *InvokeServiceRequest, opts ...grpc.CallOption) (*v1.InvokeResponse, error)
......s
}DaprClient 的实现：
type daprClient struct {
cc *grpc.ClientConn
}
func NewDaprClient(cc *grpc.ClientConn) DaprClient {
return &daprClient{cc}
}
func (c *daprClient) InvokeService(ctx context.Context, in *InvokeServiceRequest, opts ...grpc.CallOption) (*v1.InvokeResponse, error) {
out := new(v1.InvokeResponse)
err := c.cc.Invoke(ctx, "/dapr.proto.runtime.v1.Dapr/InvokeService", in, out, opts...)
if err != nil {
return nil, err
}
return out, nil
}
AppCallbackClient
// AppCallbackClient is the client API for AppCallback service.
//
// For semantics around ctx use and closing/ending streaming RPCs, please refer to https://godoc.org/google.golang.org/grpc#ClientConn.NewStream.
type AppCallbackClient interface {
// Invokes service method with InvokeRequest.
OnInvoke(ctx context.Context, in *v1.InvokeRequest, opts ...grpc.CallOption) (*v1.InvokeResponse, error)
......
}AppCallbackClient 的实现：
type appCallbackClient struct {
cc *grpc.ClientConn
}
func NewAppCallbackClient(cc *grpc.ClientConn) AppCallbackClient {
return &appCallbackClient{cc}
}
func (c *appCallbackClient) OnInvoke(ctx context.Context, in *v1.InvokeRequest, opts ...grpc.CallOption) (*v1.InvokeResponse, error) {
out := new(v1.InvokeResponse)
err := c.cc.Invoke(ctx, "/dapr.proto.runtime.v1.AppCallback/OnInvoke", in, out, opts...)
if err != nil {
return nil, err
}
return out, nil
}Dapr服务调用的go sdk定义
Dapr服务调用的go sdk定义
go sdk使用案例
https://github.com/dapr/go-sdk
要在另一个使用Dapr sidecar运行的服务上调用特定的方法，Dapr客户端提供了两个选项。
调用一个没有任何数据的服务：
resp, err = client.InvokeService(ctx, "service-name", "method-name") 还有带数据调用服务：
content := &DataContent{
ContentType: "application/json",
Data: []byte(`{ "id": "a123", "value": "demo", "valid": true }`)
}
resp, err := client.InvokeServiceWithContent(ctx, "service-name", "method-name", content)go sdk提供的API
https://github.com/dapr/go-sdk/blob/d6de57c71a1d3c7ce3a3b81385609dfba18a1a18/client/invoke.go
go sdk在 client 上封装了两个方法用于服务调用，InvokeService方法用来发送不带数据的请求：
// InvokeService invokes service without raw data ([]byte).
func (c *GRPCClient) InvokeService(ctx context.Context, serviceID, method string) (out []byte, err error) {
...
}InvokeServiceWithContent方法用来发现带数据的请求：
// InvokeServiceWithContent invokes service without content (data + content type).
func (c *GRPCClient) InvokeServiceWithContent(ctx context.Context, serviceID, method string, content *DataContent) (out []byte, err error) {
......
}DataContent 的定义：
// DataContent the service invocation content
type DataContent struct {
// Data is the input data
Data []byte
// ContentType is the type of the data content
ContentType string
}
