LambdaClient

Implements: IOpenable, IConfigurable, IReferenceable

Description

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

Configuration parameters

• connections:
  • discovery_key: (optional) key to retrieve the connection from IDiscovery
  • region: (optional) AWS region
• credentials:
  • store_key: (optional) key to retrieve the credentials from ICredentialStore
  • access_id: AWS access/client id
  • access_key: AWS access/client key
• options:
  • connect_timeout: (optional) connection timeout in milliseconds (default: 10 sec)

References

• *:logger:*:*:1.0 - (optional) ILogger components to pass log messages.
• *:counters:*:*:1.0 - (optional) ICounters components to pass collected measurements.
• *:discovery:*:*:1.0 - (optional) IDiscovery services to resolve connections.
• *:credential-store:*:*:1.0 - (optional) Credential stores to resolve credentials.

Constructors

Creates a new instance of this client.

public constructor(name: string)

• name: string - service name.

Fields

Instance methods

call

Calls an AWS Lambda Function action.

protected call(cmd: string, correlationId: string, params: any = {}): Promise<any>

• cmd: string - action name to be called.
• correlationId: string - (optional) transaction id used to trace execution through the call chain.
• params: any - (optional) action parameters.
• returns: Promise<any> - action result.

callOneWay

Calls a AWS Lambda Function action asynchronously without waiting for response.

protected callOneWay(cmd: string, correlationId: string, params: any = {}): Promise<any>

• cmd: string - an action name to be called.
• correlationId: string - (optional) transaction id used to trace execution through the call chain.
• params: any - (optional) action parameters.
• returns: Promise<any> - action result.

close

Closes 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.

instrument

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

invoke

Performs AWS Lambda Function invocation.

protected invoke(invocationType: string, cmd: string, correlationId: string, args: any): Promise<any>

• invocationType: string - invocation type: “RequestResponse” or “Event”
• cmd: string - action name to be called.
• correlationId: string - (optional) transaction id used to trace execution through the call chain.
• args: any - action arguments
• returns: Promise<any> - action result.

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.

setReferences

Sets references to dependent components.

public setReferences(references: IReferences): void

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

Examples

class MyLambdaClient extends LambdaClient implements IMyClient {
    ...
 
    public async getData(correlationId: string, id: string): Promise<MyData> {
        let timing = this.instrument(correlationId, 'myclient.get_data');
        const result = await this.call("get_data" correlationId, { id: id });
        timing.endTiming();
        return result;
    }
    ...
}
let client = new MyLambdaClient();
client.configure(ConfigParams.fromTuples(
    "connection.region", "us-east-1",
    "connection.access_id", "XXXXXXXXXXX",
    "connection.access_key", "XXXXXXXXXXX",
    "connection.arn", "YYYYYYYYYYYYY"
));
 *     
const result = await client.getData("123", "1");

See also

• LambdaFunction

• CommandableLambdaClient