GrpcClient

Implements: IOpenable, IReferenceable, IConfigurable

Description

The GrpcClient class allows you to create clients that call remote endpoints using the GRPC protocol.

Configuration parameters

• 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
• options:
  • retries: number of retries (default: 3)
  • connect_timeout: connection timeout in milliseconds (default: 10 sec)
  • timeout: invocation timeout in milliseconds (default: 10 sec)

Constructors

Creates a new instance of the grpc client.

public constructor(clientTypeOrPath: any, clientName?: string, packageOptions?: any)

• clientTypeOrPath: any - TODO: add description
• clientName: string - client’s name.
• packageOptions: any - TODO: add description

Fields

Instance methods

call

Calls a remote method via GRPC protocol.

protected call(method: string, context?: IContext, request: any = {}): Promise<any>

• method: string - name of the calling method
• context: IContext - (optional) a context to trace execution through a call chain.
• request: any - (optional) request object.
• returns: Promise<any> - (optional) feature that receives the result object or error.

close

Closes the component and frees used resources.

public close(context: IContext): Promise<void>

• context: IContext - (optional) a context to trace execution through a call chain.

configure

Configures the component by passing its configuration parameters.

public configure(config: ConfigParams): void

• config: ConfigParams - configuration parameters to be set.

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(context: IContext, name: string): InstrumentTiming

• context: IContext - (optional) a context to trace execution through a call chain.
• name: string - method name.
• returns: InstrumentTiming - CounterTiming object used to end the time measurement.

isOpen

Checks if the component is open.

public isOpen(): boolean

• returns: boolean - Returns True if the component is open and False otherwise.

open

Opens the component.

public open(context: IContext): Promise<void>

• context: IContext - (optional) a context to trace execution through a call chain.

setReferences

Sets references to dependent components.

public setReferences(references: IReferences): void

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

Examples

class MyGrpcClient extends GrpcClient implements IMyClient {
    ...
    public getData(context: IContext, id: string): Promise<MyData> {
   
        let timing = this.instrument(context, 'myclient.get_data');
        try {
           return await this.call("get_data", context, { id: id });
        } catch (err) {
            timing.endFailure(err);
            throw err;
        } finally {
            timing.endSuccess();
        }
    }       
   ...
}

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

let result = await client.getData("123", "1", );