README
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lambda-invoker
Lightweight library to simplify invoking a lambda function.
Usage
Initialze an Invoker, passing it a lambda.Service and the arn of the lambda function being invoked. Then invoke the function passing it your json request.
invoker := New(svc, "function-arn")
rsp, err := invoker.Invoke(ctx, []byte(`{"request":"content"}`))
// Do something with output.
Router
It's likely you'll want to use the invoker with 'edstell/lambda-router'; an
Option has been included with this package to make this easy. Initialize a new
Invoker, passing it the 'AsProcedure' option.
AsProcedure takes a procedure name which instructs the invoked function which
handler to route this request to, and an 'unmarshalError' func - which will
be used when unmarshaling a returned error. This allows you to define your own
custom error implementations and pass them between lambda functions.
You'll need to initialize a new Invoker for each procedure you intend to call.
invoker := New(svc, "function-arn", AsProcedure("On", unmarshalErrorFunc))
rsp, err := invoker.Invoke(ctx, []byte(`{"request":"content"}`))
Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
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Functions ¶
This section is empty.
Types ¶
type Error ¶
type Error struct {
StatusCode int64
// contains filtered or unexported fields
}
Error wraps an error message with a status code.
type Invoker ¶
type Invoker struct {
MutateInput func(*lambda.InvokeInput) error
MutateOutput func(*lambda.InvokeOutput) error
// contains filtered or unexported fields
}
Invoker is a wrapper around the aws lambda invoker implementation. It provides a convenient layer for middleware, as well as exposing a simpler method to invoke a lambda function with.
func New ¶
func New(li LambdaInvoker, arn string, opts ...Option) *Invoker
New initializes an Invoker with the options passed.
func (*Invoker) Invoke ¶
func (i *Invoker) Invoke(ctx context.Context, body json.RawMessage) (json.RawMessage, error)
Invoke _invokes_ the lambda function passing body as the InvokeInput.Payload and returning the InvokeOutput.Payload as the result. If InvokeOutput contains a FunctionError an Error is returned, wrapping the status code. By default lambda functions are invoked as a 'RequestResponse', but input mutators can be passed to change the InvocationType.
type LambdaInvoker ¶
type LambdaInvoker interface {
InvokeWithContext(context.Context, *lambda.InvokeInput, ...awsreq.Option) (*lambda.InvokeOutput, error)
}
LambdaInvoker abstracts the logic of invoking a lambda function behind an interface, this is to allow mocking the aws Lambda implementation.
type Option ¶
type Option func(*Invoker)
Option implementations can mutate the Invoker allowing configuration of how invokations of a lambda function should be performed.
func AsProcedure ¶
func AsProcedure(procedure string, unmarshalError func(json.RawMessage) error) Option
AsProcedure configures invocation to wrap payloads in router.Request/Response setting the Procedure field, and unmarshaling returned errors with the unmarshaler.
Source Files