Testing a Hello-World AWS Lambda Function Locally with Docker
Testing a hello_world AWS Lambda Function Locally with Docker#
At this point, before we've even made any code updates - we have a fully functioning and deployable lambda. Sure it just says "Hello World" - but it's a start. We'll go ahead and invoke it locally just to confirm our environment is configured correctly.
dicebot directory, we will use the command
sam build -u build a SAM package with docker. The
-u flag is necessary to ensure
docker is used to build the package. Using
-u is not strictly required, but we recommended always using it so that we are sure our package is being built against the correct target environment.
Once the package building step has completed, we can then send a test function to it with
sam local invoke --event events/first_function_event.json and see the output.
In most cases, we'll just chain these two commands together, and send
sam build -u && sam local invoke --event events/first_function_event.json
Expected output from
sam build -u
Starting Build inside a container
Built Artifacts : .aws-sam/build
Built Template : .aws-sam/build/template.yaml