Is there a way to create a Lambda@Edge from the command line? Or is there a way to take an existing lambda and deploy it to cloudfront from the command line?
I've looked here: aws lambda ?
and here: aws cloudfront ?
The only thing that looks remotely useful is update-distribution.
You've already found it- although I'll grant you that it's pretty arduous.
aws cloudfront update-distribution includes the array key LambdaFunctionAssociations, which allows you to link existing lambdas (by LambdaFunctionARN) to various cache responses.
More information here: https://docs.aws.amazon.com/cli/latest/reference/cloudfront/update-distribution.html
Unfortunately, as seems to be the case with all of cloudfront, there's no helper commands to just add/remove lambdas.
If you're scripting you might want to look at get-distribution which allows you to at least pre-populate most of the distribution configuration from whatever you've set up in the console; rather than learning everything from scratch.
This document might also be helpful for you: https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/distribution-overview-required-fields.html as it discusses what information you have to provide to the distribution operation commands.
