LambdaClient

Abstract client that calls AWS Lambda Functions.

Implements: IOpenable, IConfigurable, IReferenceable

Description

When making calls, the “cmd” parameter determines 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.

LambdaClient(name: str)

  • name: str - service name.

Fields

_connection

AWS connection parameters

_connection: AwsConnectionParams

_connection_resolver

The connection resolver.

_connection_resolver: AwsConnectionResolver

_counters

Performance counters.

_counters: CompositeCounters

_dependency_resolver

Dependencies resolver.

_dependency_resolver: DependencyResolver

_lambda

Reference to AWS Lambda Function.

_lambda: Any

_logger

Logger.

_logger: CompositeLogger

_opened

Opened flag.

_opened: bool

_tracer

Tracer.

_tracer: CompositeTracer

Instance methods

_call

Calls an AWS Lambda Function action.

_call(cmd: str, correlation_id: Optional[str], params: dict = None): Any

  • cmd: str - action name to be called.
  • correlation_id: Optional[str] - (optional) transaction id used to trace execution through the call chain.
  • params: dict - (optional) action parameters.
  • returns: Any - action result.

call_one_way

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

call_one_way(cmd: str, correlation_id: Optional[str], params: dict = None): Any

  • cmd: str - an action name to be called.
  • correlation_id: Optional[str] - (optional) transaction id used to trace execution through the call chain.
  • params: dict - (optional) action parameters.
  • returns: Any - action result.

close

Closes component and frees used resources.

close(correlation_id: Optional[str])

  • correlation_id: Optional[str] - (optional) transaction id used to trace execution through the call chain.

configure

Configures a component by passing its configuration parameters.

configure(config: ConfigParams)

  • 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.

_instrument(correlation_id: Optional[str], name: str): InstrumentTiming

  • correlation_id: Optional[str] - (optional) transaction id used to trace execution through the call chain.
  • name: str - a method name.
  • returns: InstrumentTiming - object to end the time measurement.

invoke

Performs AWS Lambda Function invocation.

_invoke(invocation_type: str, cmd: str, correlation_id: Optional[str], args: Any) -> Any

  • invocation_type: str - invocation type: “RequestResponse” or “Event”
  • cmd: str - action name to be called.
  • correlation_id: Optional[str] - (optional) transaction id used to trace execution through the call chain.
  • args: Any - action arguments
  • returns: Any - action result.

is_open

Checks if the component is open.

is_open(): bool

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

open

Opens the component.

open(correlation_id: Optional[str])

  • correlation_id: Optional[str] - (optional) transaction id used to trace execution through the call chain.

set_references

Sets references to dependent components.

set_references(references: IReferences)

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

Examples

class MyLambdaClient(LambdaClient, IMyClient):

    ...

    def get_data(self, correlation_id: str, id: str) -> MyData: 
        timing = self._instrument(correlation_id, 'myclient.get_data')
        result = self._call("get_data", correlation_id, { 'id': id })
        timing.end_timing()
        return result
    
    ...

client = MyLambdaClient()

client.open("123")

client.configure(ConfigParams.from_tuples(
    "connection.region", "us-east-1",
    "connection.access_id", "XXXXXXXXXXX",
    "connection.access_key", "XXXXXXXXXXX",
    "connection.arn", "YYYYYYYYYYYYY"
))

result = client.get_data("123", "1")

See also