LambdaClient

Abstract client that calls AWS Lambda Functions.

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

NewLambdaClient

Creates a new instance of this client.

NewLambdaClient() *LambdaClient

  • name: string - service name.

Fields

Connection

AWS connection parameters

Connection: *AwsConnectionParams

ConnectionResolver

The connection resolver.

ConnectionResolver: *AwsConnectionResolver

Counters

Performance counters.

Counters: *CompositeCounters

DependencyResolver

Dependencies resolver.

DependencyResolver: *DependencyResolver

Lambda

Reference to AWS Lambda Function.

Lambda: *lambda.Lambda

Logger

Logger.

Logger: *CompositeLogger

Opened

Opened flag.

Opened: bool

Tracer

Tracer.

Tracer: *CompositeTracer

Methods

Call

Calls an AWS Lambda Function action.

(c *LambdaClient) Call(ctx context.Context, cmd string, correlationId string, params map[string]interface{}) (result *lambda.InvokeOutput, err error)

  • ctx: context.Context - operation context.
  • cmd: string - action name to be called.
  • correlationId: string - (optional) transaction id used to trace execution through the call chain.
  • params: map[string]interface{} - (optional) action parameters.
  • returns: (result *lambda.InvokeOutput, err error) - action result.

CallOneWay

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

(c *LambdaClient) CallOneWay(prototype reflect.Type, cmd string, correlationId string, params map[string]interface{}) error

  • prototype: reflect.Type - type for convert result. Set nil for return raw []byte
  • cmd: string - action name to be called.
  • correlationId: string - (optional) transaction id used to trace execution through the call chain.
  • params: map[string]interface{} - (optional) action parameters.
  • returns: error - error or null for success.

Close

Closes component and frees used resources.

(c *LambdaClient) Close(ctx context.Context, correlationId string) error

  • ctx: context.Context - operation context.
  • correlationId: string - (optional) transaction id used to trace execution through the call chain.
  • returns: error - error or null for success.

Configure

Configures a component by passing its configuration parameters.

(c *LambdaClient) Configure(ctx context.Context, config *ConfigParams)

  • ctx: context.Context - operation context.
  • config: *ConfigParams - configuration parameters to be set.

Instrument

Adds instrumentation to log calls and measures call time. It returns an InstrumentTiming object that is used to end the time measurement.

(c *LambdaClient) Instrument(ctx context.Context, correlationId string, name string) *CounterTiming

  • ctx: context.Context - operation context.
  • correlationId: string - (optional) transaction id used to trace execution through the call chain.
  • name: string - method name.
  • returns: *CounterTiming - object to end the time measurement.

Invoke

Performs AWS Lambda Function invocation.

(c *LambdaClient) Invoke(ctx context.Context, invocationType string, cmd string, correlationId string, args map[string]interface{}) (result *lambda.InvokeOutput, err error)

  • ctx: context.Context - operation context.
  • 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: map[string]interface{} - action arguments
  • returns: (result *lambda.InvokeOutput, err error) - action result.

IsOpen

Checks if the component is open.

(c *LambdaClient) IsOpen() bool

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

Open

Opens the component.

(c *LambdaClient) Open(ctx context.Context, correlationId string) error

  • ctx: context.Context - operation context.
  • correlationId: string - (optional) transaction id used to trace execution through the call chain.
  • returns: error - error or null for success.

SetReferences

Sets references to dependent components.

(c *LambdaClient) SetReferences(ctx context.Context, references IReferences)

  • ctx: context.Context - operation context.
  • references: IReferences - references to locate the component dependencies.

Examples

type MyLambdaClient struct  {
	*LambdaClient
	...
}

func (c* MyLambdaClient) getData(ctx context.Context, correlationId string, id string)(result MyData, err error){
	timing := c.Instrument(ctx, correlationId, "myclient.get_data");
	callRes, callErr := c.Call(ctx ,"get_data" correlationId, map[string]interface{ "id": id })
	if callErr != nil {
		return callErr
	}
	defer timing.EndTiming(ctx, nil)
	return awsclient.HandleLambdaResponse[*cdata.DataPage[MyData]](calValue)
}
...


client = NewMyLambdaClient();
client.Configure(context.Background(), NewConfigParamsFromTuples(
    "connection.region", "us-east-1",
    "connection.access_id", "XXXXXXXXXXX",
    "connection.access_key", "XXXXXXXXXXX",
    "connection.arn", "YYYYYYYYYYYYY"
))

data, err := client.GetData(context.Background(), "123", "1")
...

See also