Creating a Lambda using AWS CLI

Now that we’ve got the CLI set up, we can use it to make our lives much easier. To create a new function, you need to have a folder containing an index.js file with a basic Lambda code in. Navigate into that folder in your terminal and now you can run these commands:

zip ./index.zip *
aws lambda create-function \
 --function-name your-function-name \
--runtime nodejs8.10 \
--role your-lambda-role \
 --handler index.handler \
 --zip-file fileb://index.zip

Switch out the your-lambda-role for the arn of the role that you created earlier. You can find this by going back to the IAM service in AWS and selecting Roles and clicking on your Lambda role:

When you run this it will return a JSON blob with some information about your newly created Lambda.

If you edit your index.js code and want to update the Lambda, then there are three commands you need to run:

rm index.zip
zip ./index.zip *
aws lambda update-function-code \
--function-name your-function-name \
--zip-file fileb://index.zip

Using these scripts, you can now write your code locally and deploy it to AWS. This is good but it can be improved, which is what we're going to do next.