GrpcService

Implements: IOpenable, IConfigurable, IRegisterable, IUnreferenceable

Description

The GrpcService class allows you to create services that receive remote calls via the GRPC protocol.

Configuration parameters

• dependencies:
  • endpoint: override for GRPC Endpoint dependency
  • controller: override for Controller dependency
• connection(s):
  • discovery_key: (optional) key to retrieve the connection from IDiscovery
  • protocol: connection protocol: http or https
  • host: host name or IP address
  • port: port number
  • uri: resource URI or connection string with all parameters in it
• credentials:
  • ssl_key_file: SSL private key in PEM
  • ssl_crt_file: SSL certificate in PEM
  • ssl_ca_file: certificate authorities (root cerfiticates) in PEM

References

• *:discovery:*:*:1.0 - (optional) IDiscovery services
• *:logger:*:*:1.0 - (optional) ILogger components to pass log messages
• *:counters:*:*:1.0 - (optional) ICounters components to pass collected measurementsand as specified by the counter’s source.

Constructors

Creates a new instance of the service.

public constructor(serviceOrPath: any, serviceName?: string, packageOptions?: any)

• serviceOrPath: any - TODO: add description
• serviceName: string - service name.
• packageOptions: any - TODO: add description

Fields

Abstract methods

register

Registers all service routes in the HTTP endpoint.

This method is called by the service and must be overriden in child classes.

public abstract register()

Instance methods

applyValidation

Performs a validation.

protected applyValidation(schema: Schema, action: (call: any) => Promise<any>): (call: any) => Promise<any>

• schema: Schema - TODO: add description
• action: (call: any) => Promise<any> - TODO: add description
• returns: (call: any) => Promise<any> - TODO: add description

applyInterceptors

Applies given action to the interseptors

protected applyInterceptors(action: (call: any) => Promise<any>): (call: any) => Promise<any>

• action: (call: any) => Promise<any>) - TODO: add description
• returns: (call: any) => Promise<any> - TODO: add description

close

Closes the component and frees used resources.

public close(correlationId: string): Promise<void>

• correlationId: string - (optional) transaction id used to trace execution through the call chain.

configure

Configures component by passing configuration parameters.

public configure(config: ConfigParams): void

• config: ConfigParams - configuration parameters to be set.

isOpen

Checks if the component is open.

public isOpen(): boolean

• returns: boolean -True if the endpoint is open with an actively listening GRPC server.

instrument

Adds instrumentation to log calls and measures call time. It returns a CounterTiming object that is used to end the time measurement.

protected instrument(correlationId: string, name: string): InstrumentTiming

• correlationId: string - (optional) transaction id used to trace execution through the call chain.
• name: string - method name.
• returns: InstrumentTiming -Timing object to end the time measurement.

open

Opens the component.

public open(correlationId: string): Promise<void>

• correlationId: string - (optional) transaction id used to trace execution through the call chain.

registerInterceptor

Registers a middleware for methods in GRPC endpoint.

protected registerInterceptor(action: (call: any, next: (call: any) => Promise<any>) => Promise<any>): void

• action: (call: any, next: (call: any) => Promise<any>) => Promise<any> - an action function that is called when middleware is invoked.

registerMethod

Registers a middleware for methods in GRPC endpoint.

protected registerMethod(name: string, schema: Schema, action: (call: any) => Promise<any>): void

• name: string - method name
• schema: Schema - validation schema to validate received parameters.
• action: (call: any) => Promise<any> - action function that is called when operation is invoked.

registerMethodWithAuth

Registers a method with authorization.

protected registerMethodWithAuth(name: string, schema: Schema, authorize: (call: any, next: (call: any) => Promise<any>) => Promise<any>, action: (call: any) => Promise<any>): void

• name: string - a method name
• schema: Schema - a validation schema to validate received parameters.
• authorize: (call: any, next: (call: any) => Promise<any>) => Promise<any> - an authorization interceptor
• action: (call: any) => Promise<any> - an action function that is called when operation is invoked.

setReferences

Sets references to dependent components.

public setReferences(references: IReferences): void

• references: IReferences - references to locate the component dependencies.

unsetReferences

Unsets (clears) previously set references to dependent components.

public unsetReferences(): void

Examples

class MyGrpcService extends GrpcService {
   private _controller: IMyController;
   ...
   public constructor() {
      super('... path to proto ...', '.. service name ...');
      this._dependencyResolver.put(
          "controller",
          new Descriptor("mygroup","controller","*","*","1.0")
      );
   }
   public setReferences(references: IReferences): void {
      super.setReferences(references);
      this._controller = this._dependencyResolver.getRequired<IMyController>("controller");
   }
   public register(): void {
       registerMethod("get_mydata", null, async (call) => {
           let correlationId = call.request.correlationId;
           let id = call.request.id;
           return await this._controller.getMyData(correlationId, id);
       });
       ...
   }
}

let service = new MyGrpcService();
service.configure(ConfigParams.fromTuples(
    "connection.protocol", "http",
    "connection.host", "localhost",
    "connection.port", 8080
));

service.setReferences(References.fromTuples(
   new Descriptor("mygroup","controller","default","default","1.0"), controller
));

await service.open("123");
console.log("The GRPC service is running on port 8080");