go-programming | compendium material for Todd McLeod | Learning library

There are a couple of issues here. First is the incompatibility of the types. Go will return a GoInt. Second issues is that the Add() function has to be exported to get the desired header file. If you don't want to change your Go code, then in C you have to use the GoInt which is a long long.

A complete example is:

test.go

The answer seems quite simple actually. It is a problem with typecasting which I missed.

The method should accept *C.char

When you call a function or a method and you pass parameters to it, a copy is made from the values, and the function can only access these copies.

This means if the function attempts to modify / change the copies, it will not change the original value.

For example:

Remember that strings in Go are like slices. They are composed of a pointer to the backing data and the length. This is why in your code, GoString is defined as:

One of the most common reasons to get Internal server error is that your Lambda function is either crashing or not returning what is expected by the triggering service.

In this case I suspect a bit of both.

When you proxy through API Gateway your event payload isn't just what you POST'ed. You can find out more about the shape of events here, including those of an API Gateway request: (https://docs.aws.amazon.com/lambda/latest/dg/eventsources.html#eventsources-api-gateway-request).

Your lambda is crashing because the event you get from API Gateway can not be cast into your type MyEvent struct, as it does not have a name property; in fact, the body of the request is actually in event.body as a string which has to be decoded.

A good guide to the events your expected for responses for API Gateway with lambda can be found here (https://serverless.com/framework/docs/providers/aws/events/apigateway/)

It's more normal to use ok for the boolean variable name. This is equivalent to:

I found a way around this by having my JSON in a file rather than in the command itself, this doesn't solve the issue I'm experiencing in the question but it's a way to invoke the function with Json

I added a events/startAndEnd.json file that contains my json data:

It seems not possible. I assume, you're looking at the metrics in Amazon CloudWatch

AWS Lambda automatically monitors functions on your behalf, reporting metrics through Amazon CloudWatch. These metrics include total invocations, errors, duration, throttles, DLQ errors and Iterator age for stream-based invocations. https://docs.aws.amazon.com/lambda/latest/dg/monitoring-functions-metrics.html

Now, let's see how do they define errors

Metric "Errors" measures the number of invocations that failed due to errors in the function (response code 4XX).

So, if you want to see the errors on that graph, you have to respond with the proper codes. If you're concerned about exposing the error stacktrace, here is a good read Error handling with API Gateway and Go Lambda functions. The basic idea there is about creating a custom lambdaError type, meant to be used by a Lambda handler function to wrap errors before returning them. This custom error message

<- is for receiving from a Channel, for this neither time.Until or Truncate returns a channel.

In this case the error message is identifying the issue, but doesn't really tell what actually to do differently.

go DOES provide some time methods that do return channels. One of which is time.After