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 LambdaClient(String name)

• name: string - service name.

Fields

Instance methods

call

Calls an AWS Lambda Function action.

protected T call(TypeReference type, String cmd, IContext context, Map<String, Object> params) throws ApplicationException

• cmd: String - action name to be called.
• context: IContext - (optional) a context to trace execution through a call chain.
• params: Map<String, Object> - (optional) action parameters.
• returns: <T> - action result.

callOneWay

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

protected T callOneWay(Class type, String cmd, IContext context, Map<String, Object> params) throws ApplicationException

• cmd: String - an action name to be called.
• context: IContext - (optional) a context to trace execution through a call chain.
• params: Map<String, Object> - (optional) action parameters.
• returns: <T> - action result.

close

Closes component and frees used resources.

public void close(IContext context)

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

configure

Configures a component by passing its configuration parameters.

public void configure(ConfigParams config) throws ConfigException

• 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 InstrumentTiming instrument(IContext context, String name)

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

invoke

Performs AWS Lambda Function invocation.

protected T invoke(Class type, String invocationType, String cmd, IContext context, Map<String, Object> args) throws ApplicationException

• invocationType: String - invocation type: “RequestResponse” or “Event”
• cmd: String - action name to be called.
• context: IContext - (optional) a context to trace execution through a call chain.
• args: Map<String, Object> - action arguments
• returns: <T> - action result.

isOpen

Checks if the component is open.

public boolean isOpen(IContext context)

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

open

Opens the component.

public void open(IContext context)

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

setReferences

Sets references to dependent components.

public void setReferences(IReferences references) throws ReferenceException

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

Examples

class MyLambdaClient extends LambdaClient implements IMyClient {
    ...
 
    public MyData getData(IContext context, String id) {
        Timing timing = this.instrument(context, "myclient.get_data");
        MyData result = this.call(MyData.class, "get_data", context, new MyData(id));
        timing.endTiming();
        return result;
    }
    ...
}
    MyLambdaClient  client = new MyLambdaClient();
    client.configure(ConfigParams.fromTuples(
        "connection.region", "us-east-1",
        "connection.access_id", "XXXXXXXXXXX",
        "connection.access_key", "XXXXXXXXXXX",
        "connection.arn", "YYYYYYYYYYYYY"
    ));
 
    MyData result = client.getData("123", "1");

See also

• LambdaFunction

• CommandableLambdaClient