keskiviikko 20. syyskuuta 2017

Amazon Cloudformation and tagging

AWS Cloudformation has multiple different commands in aws cli, like "create-stack", "update-stack" and "deploy". Each of these have their good and bad sides. For multiple reasons, we've decided to use "deploy". But the problem then becomes tagging. "Create-stack" and "update-stack" both have support for giving tags which are then propagated to all supported resources, but deploy does not have it. To make things worse, some Cloudformation types does not support tags as their properties, but they seem to get tags from Cloudformation stack if tags are there.

Now we do after deploy "aws cloudformation update-stack --stack-name <some> --tags ...". This becomes quite easy with some scripting when you have jq!

As update-stack wants to have all parameters with "UsePreviousValue=true", use some jq to generate necessary parameters. Then we take existing Parameters we've used for tagging and generate tags from that.

Well, actually "quite easy" is a lie, as I had some problems in understanding right syntax to replace key in JSON array with jq.