LambdaFunction

Extends: Container

Description

The LambdaFunction class allows you to create an abstract AWS Lambda function that acts as a container to instantiate and run components, and expose them via an external entry point.

Important points

• When handling calls the “cmd” parameter determines what action shall be called, while the other parameters are passed to the action itself.

• Container configuration for this Lambda function is stored in "./config/config.yml" file. But this path can be overriden by CONFIG_PATH environment variable.

References

• *:logger:*:*:1.0: (optional) ILogger components to pass log messages.
• *:counters:*:*:1.0: (optional) ICounters components to pass collected measurements.
• *:service:lambda:*:1.0: (optional) ILambdaService services to handle action requests
• *:service:commandable-lambda:*:1.0: (optional) ILambdaService services to handle action requests

Constructors

Creates a new instance of this lambda function.

public constructor(name: string, description?: string)

• name: string - (optional) a container name (accessible via ContextInfo).
• description: string - (optional) container description (accessible via ContextInfo).

Fields

Instance methods

act

Calls registered action in this lambda function. The “cmd” parameter in the action parameters determines what action shall be called.

• This method shall only be used in testing.

public act(params: any): Promise<any>

• params: any - action parameters.
• returns: Promise<any> - result

execute

Executes this AWS Lambda function and returns the result. This method can be overloaded in child classes if it is necessary to change the default behavior

protected execute(event: any): Promise<any>

• event: any - event parameters (or function arguments)
• returns: Promise<any> - result of the function execution.

getHandler

Gets an entry point into this lambda function.

public getHandler(): (event: any) => Promise<\any>

• returns: (event: any) => Promise<\any> - incoming event object with invocation parameters.

instrument

Gets entry point into this lambda function.

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 - 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.

register

Registers all actions in this lambda function.

• Note: Overloading of this method has been deprecated. Use LambdaService instead.

protected register(): void

registerAction

Registers an action in this lambda function.

• Note: This method has been deprecated. Use LambdaService instead.

protected registerAction(cmd: string, schema: Schema, action: (params: any) => Promise<any>): void

• cmd: string - action/command name.
• schema: Schema - validation schema used to validate received parameters.
• action: (params: any) => Promise<any> - action function that is called when the action is invoked.

registerServices

Registers all lambda services in the container.

protected registerServices(): void

run

Runs this lambda function, loads container configuration, instantiates components and manages their lifecycle. Makes this function ready to access action calls.

public run(): Promise<void>

setReferences

Sets references to dependent components.

public setReferences(references: IReferences): void

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

Examples

class MyLambdaFunction extends LambdaFunction {
    public constructor() {
        base("mygroup", "MyGroup lambda function");
    }
}
let lambda = new MyLambdaFunction();
 
await service.run();
console.log("MyLambdaFunction is started");

See also

• LambdaClient