aws-sam-cli: Sam local invoke (go) not honoring timeout in context

I rolled back to SAM CLI, version 1.12.0 to get this working again.

I’m experiencing this issue as well while it was working earlier on when I had v1.15. I’ve tried upgrading to v1.18.1 but that didn’t help. I have the exact same problem as @momotaro98 described.

If you do not set warm containers, they aren’t used. This is likely related to #2519

This issue appears to be fixed in the latest version: 1.37.0

Or at least my use case appears to be bug free. A non-expired context.Context is given to my Lambda with the correct timeout.

Go code:

package main

import (
	"context"
	"log"
	"os"

	"github.com/aws/aws-lambda-go/lambda"
)

type handler struct {
	logger *log.Logger
}

// Invoke implements the lambda.Handler interface and shows context.Context information.
func (h handler) Invoke(ctx context.Context, _ []byte) (response []byte, err error) {
	h.logger.Printf("%+v", ctx)

	select {
	case <-ctx.Done():
		h.logger.Println("Context expired.")
		err := ctx.Err()
		h.logger.Printf("Error: %s", err.Error())
		response = []byte(`{"statusCode":200,"headers":null,"multiValueHeaders":null,"body":"Failed due to expired context on invocation."}`)
	default:
		h.logger.Println("Context not expired.")
		response = []byte(`{"statusCode":200,"headers":null,"multiValueHeaders":null,"body":"Successfully returned response."}`)
	}

	return response, nil
}

func main() {
	logger := log.New(os.Stdout, "", log.LstdFlags)

	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	h := handler{
		logger: logger,
	}

	lambda.StartHandlerWithContext(ctx, h)
}

template.yml:

AWSTemplateFormatVersion: "2010-09-09"
Description: "An example Golang AWS SAM Lambda project."
Transform: "AWS::Serverless-2016-10-31"


Parameters:
  VaultToken:
    Type: "String"


Globals:
  Function:
    Handler: "main"
    Timeout: 10
    Runtime: "go1.x"


Resources:

  exampleOne:
    Type: "AWS::Serverless::Function"
    Properties:
      CodeUri: "cmd/one"
      Events:
        ApiEvent:
          Type: "HttpApi"
        Api:
          Type: "Api"
          Properties:
            Path: "/one"
            Method: "get"

Output:

$ sam --version && date && sam build && sam local invoke
SAM CLI, version 1.37.0
Sat 15 Jan 2022 04:19:18 PM EST
Building codeuri: /home/micah/GolandProjects/go-aws-sam-lambda-example/cmd/one runtime: go1.x metadata: {} architecture: x86_64 functions: ['exampleOne']
Running GoModulesBuilder:Build

Build Succeeded

Built Artifacts  : .aws-sam/build
Built Template   : .aws-sam/build/template.yaml

Commands you can use next
=========================
[*] Invoke Function: sam local invoke
[*] Test Function in the Cloud: sam sync --stack-name {stack-name} --watch
[*] Deploy: sam deploy --guided
        
Invoking main (go1.x)
Skip pulling image and use local one: public.ecr.aws/sam/emulation-go1.x:rapid-1.37.0-x86_64.

Mounting /home/micah/GolandProjects/go-aws-sam-lambda-example/.aws-sam/build/exampleOne as /var/task:ro,delegated inside runtime container
START RequestId: ab0e8d22-adfb-4b9f-9d0e-bccea54000b9 Version: $LATEST
2022/01/15 21:19:22 context.Background.WithCancel.WithDeadline(2022-01-15 21:19:32.075598487 +0000 UTC [9.998813556s]).WithValue(type *lambdacontext.key, val <not Stringer>).WithValue(type string, val )
2022/01/15 21:19:22 Context not expired.
{"statusCode":200,"headers":null,"multiValueHeaders":null,"body":"Successfully returned response."}END RequestId: ab0e8d22-adfb-4b9f-9d0e-bccea54000b9
REPORT RequestId: ab0e8d22-adfb-4b9f-9d0e-bccea54000b9  Init Duration: 0.20 ms  Duration: 7.44 ms       Billed Duration: 8 ms   Memory Size: 128 MB     Max Memory Used: 128 MB

Notice the date is Sat 15 Jan 2022 04:19:18 PM EST and the context expires: 2022-01-15 21:19:32.075598487 +0000 UTC. The extra couple seconds are because of the time it took the sam build command to run.

This is the same behavior with sam local start-api and the Lambda is stopped early if the timeout in template.yml is reached.

++, got same bug now

For anyone wanting to know how to downgrade, you can use Pip3:

pip3 install --user 'aws-sam-cli==1.12.0'

This version seems to be working for me.