How do you push the files to all of your containers? I’ve done this in the past with app specific endpoints but never found a solution I liked with containers.
We currently persist the feature flag config in a database where the containers pull it from. Not the optimal solution but that was a natural evolution from a system we already had in place.
Ah that’s a super nice feature. I’m mostly familiar with AWS who don’t have a neat way of doing this, you end up with a bespoke solution either with lambdas pushing to shared volumes or just polling s3 for updates.
If you are using kubernetes, you can mount the secret/ConfigMap as a volume and it will be updated automatically when changes occur. Then your application merely watches the file for updates.
Being on AWS, using EKS feels like overkill when you're talking $75/month just for having it managed by AWS. This doesn't work with ECS, unfortunately, or if you're just running docker on EC2.
AWS has a native service for this called AppConfig and has agents that can pull and cache flag values so your services only need to make localhost requests.
Depending on when you’re evaluating it’s a per request overhead. You might/provably have multiple flags per request. Compared to a lambda invocation that pushes a config file to every container if it changes, it’s expensive.