aws
Support Blue/Green Deployment
I attended the session on copilot during the aws event. I understood that copilot doesn't support Blue/Green deployment. Enterprises will be able to leverage copilot cli if Blue/Green deployment support is available, hence request you to support that feature asap.
- Arun Chandrasekaran
Hi folks!
This issue has a lot of 👍, thank you all for the feedback 😍. Today, the B/G deployment support in CloudFormation has several restrictions: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/blue-green.html#blue-green-considerations
Most notably, the following restriction blocks the implementation in Copilot:
- Importing existing resources isn't currently supported for templates defining blue/green ECS deployments.
There might be other alternative routes for us to investigate to support B/G deployments perhaps with Custom Resources. I just wanted to add some clarity on why we haven't implemented it yet.
+1 on this, not sure what the current situation is here but I would benefit tremendously from this.
The existing behaviors (eg. #4838 as described by @efekarakus ) have caused us prod outages due to irreconcilable copilot behavior. Would love to see this prioritized.
Hey @jetaggart, sorry to say no updates on this for now. 😔 Since we've released overrides (YAML Patch and CDK), it's theoretically possible to write some overrides to enable Blue/Green Deployments for your Copilot service stacks. However, the limitation mentioned in the docs
Declaring output values or importing values from other stacks isn't currently supported for templates defining blue/green ECS deployments.
will make it tough, because Copilot services import shared resources from the environment stack. I haven't tested, but I think I would start with a CDK override that resolves the value of the env stack outputs and replaces the values in the service stack.
We are working on making it possible to import resources to a service so that a service could be deployed independently of an environment, which, if those resources were are imported via CFN, would make this slightly easier.
