CODEWITHSUNDEEP
amazon-web-servicesamazon-elastic-beanstalkaws-cloudformation
Dwight Schrute
Dwight Schrute

Reputation: 195

Limitations of Immutable Deployments on AWS/EB

I am trying to understand the disadvantages of immutable deployments on AWS/Elastic Beanstalk. The docs say this:

You can't perform an immutable update in concert with resource configuration changes. For example, you can't change settings that require instance replacement while also updating other settings, or perform an immutable deployment with configuration files that change configuration settings or additional resources in your source code. If you attempt to change resource settings (for example, load balancer settings) and concurrently perform an immutable update, Elastic Beanstalk returns an error.

(Source: https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/environmentmgmt-updates-immutable.html)

However, I am unable to come up with a practical scenario that would fail. I use CloudFormation templates for all of the configuration. Can the above be interpreted that I cannot deploy CloudFormation changes as well as changes to the application (.jar) at the same time?

I would be very thankful for clarification.

Upvotes: 2

Views: 1200

Answers (1)

KayakinKoder
KayakinKoder

Reputation: 3451

Take this with a grain of salt because it's just a guess based on reading the docs; I think basic support is $40/month, would be a good question to ask them to know for sure.

Can the above be interpreted that I cannot deploy CloudFormation changes as well as changes to the application (.jar) at the same time

I'm assuming you deploy your application .jar using a different process than your CloudFormation template. Meaning when you deploy source code you don't use CloudFormation, you maybe use a CI/CD tool e.g. Codeship. And when you make a change to your CloudFormation template, you log in to AWS Console and update the the template there (or use the AWS CLI tool).

Changing both at the same time would, I think, fall under what they're saying here. Don't do it for obvious reasons; you wouldn't want CloudFormation trying to make changes to an ec2 instance at the same time that EB is shutting down that instance and starting a new one. But a more common example would be I think if you happen to use .ebextensions for some configuration settings.

.ebextensions are a way to configure some things in EB that CloudFormation can't really do or easily do. They are config files that get deployed with your source code in a folder named /.ebextensions at the root of your project. An example is changing some specific linux settings https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/customize-containers-ec2.html

You wouldn't want to make a change to your application code and an .ebextension at the same time. This is just my guess at reading the docs, you could test this out pretty easily.

Upvotes: 1

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