CloudFunctionService

Implements: ICloudFunctionService, IOpenable, IConfigurable, IReferenceable

Description

The CloudFunctionService class allows you to create a service that receives remove calls via the Google Function protocol.

Important points

• This service is intended to work inside an CloudFunction container that exposes registered actions externally.

Configuration parameters

• dependencies:
  • controller: override for Controller dependency

References

• *:logger:*:*:1.0: (optional) ILogger components to pass log messages.
• *:counters:*:*:1.0: (optional) ICounters components to pass collected measurements.

Constructors

Creates an instance of this service.

public constructor(name?: string)

• name: string - name of the service used to generate an action cmd.

Fields

Instance methods

applyInterceptors

Applies interceptors to the action.

protected applyInterceptors(action: (req: Request, res: Response) => Promise<any>): (req: Request, res: Response) => Promise<any>

• action: (req: Request, res: Response) => Promise<any> - action
• returns: (req: Request, res: Response) => Promise<any> - returned result

applyValidation

Performs a validation.

protected applyValidation(schema: Schema, action: (req: Request, res: Response) => Promise<any>): (req: Request, res: Response) => Promise<any>

• schema: Schema - schema used in the validation
• action: (req: Request, res: Response) => Promise<any> - action
• returns: (req: Request, res: Response) => Promise<any> - returned result

close

Closes a 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 a component by passing its configuration parameters.

public configure(config: ConfigParams): void

• config: ConfigParams - configuration parameters to be set.

generateActionCmd

Adds ‘.cmd’ to a command name

protected generateActionCmd(name: string): string

• name: string - command name
• returns: string - command name with ‘.cmd’ added at its end.

getActions

Get all actions supported by the service.

public getActions(): CloudFunctionAction[]

• returns: CloudFunctionAction[] - array with supported actions.

getCommand

Returns command from Google Function request.

This method can be overloaded in child classes

protected getCommand(req: any): string

• req: any - the function request
• returns: string - returned command from request.

getCorrelationId

Returns correlationId from Google Function request.

This method can be overloaded in child classes

protected getCorrelationId(req: any): string

• req: any - the function request
• returns: string - returned correlationId from request.

instrument

Adds instrumentation to log calls and measures call time. It returns a Timing 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’s name.
• returns: InstrumentTiming - Timing object to end the time measurement.

isOpen

Checks if the component is open.

public isOpen(): boolean

• returns: boolean - true if the component is open and false otherwise.

open

Opens the component.

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

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

registerAction

Registers an action in Google Function function.

protected registerAction(name: string, schema: Schema, action: (req: Request, res: Response) => Promise<any>): void

• name: string - action name
• schema: Schema - validation schema used to validate received parameters.
• action: (req: Request, res: Response) => Promise<any> - action function that is called when the operation is invoked.

registerActionWithAuth

Registers an action with authorization.

protected registerActionWithAuth(name: string, schema: Schema, authorize: (req: Request, res: Response, next: (req: Request, res: Response) => Promise<any>) => Promise<any>, action: (req: Request, res: Response) => Promise<any>): void

• name: string - action’s name
• schema: Schema - validation schema used to validate received parameters.
• authorize: (req: Request, res: Response, next: (req: Request, res: Response) => Promise<any>) => Promise<any> - authorization interceptor
• action: (req: Request, res: Response) => Promise<any> - action function that is called when the operation is invoked.

registerInterceptor

Registers a middleware for actions in Google Function service.

protected registerInterceptor(action: (req: Request, res: Response, next: (req: Request, res: Response) => Promise<any>) => Promise<any>): void

• action: (req: Request, res: Response, next: (req: Request, res: Response) => Promise<any>) => Promise<any> - action function that is called when middleware is invoked.

setReferences

Sets references to dependent components.

public setReferences(references: IReferences): void

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

Abstract methods

register

Registers all service routes in an HTTP endpoint.

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

protected abstract register(): void

Examples

class MyCloudFunctionService extends CloudFunctionService {
   private _controller: IMyController;

   ...

   public constructor() {
      base('v1.myservice');
      this._dependencyResolver.put(
          "controller",
          new Descriptor("mygroup","controller","*","*","1.0")
      );
   }

   public setReferences(references: IReferences): void {
      base.setReferences(references);
      this._controller = this._dependencyResolver.getRequired<IMyController>("controller");
   }

   public register(): void {
       registerAction("get_mydata", null, async (req, res) => {
           let params = req.body;
           let correlationId = params.correlation_id;
           let id = params.id;
           const result = await this._controller.getMyData(correlationId, id);
           
           res.send(result);
       });
       ...
   }
}

let service = new MyCloudFunctionService();

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
));

service.open("123");