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Comment by elorant | Hacker News Reader

Would you recommend any resources/book for someone who hasn't got a clue what all the services at AWS are about?

There's so much going on within AWS I'd suggest approaching it the other way and identifying a few examples of things you'd need, and then researching how AWS implements those things - if you need a mainstream relational database, AWS has RDS or Aurora, etc. Need to make sure your RDS database is only accessible from your private backend app? Thats a Security Group. Need somewhere to run that app as a Docker image? ECS or EKS... which may require learning a bit about IAM so you can make sure your own user / deployment user has the right permissions to manage all these resources. Its pretty straightforward to pull a thread - but there are lots of threads you could pull.

But this has been shared here before and is still pretty good: https://adayinthelifeof.nl/2020/05/20/aws.html

I would start by understanding the infrastructure as code paradigm, built by CDK. With CDK, I would build some kind of webapp, incrementally adding more resources (lambdas, databases, etc). The true value is that you should never modify resources you provision in the console and only do it through code. Once you start developing software like this, it will be very hard to go back to the old way.

Where does this sit in relation with Terraform? Is Terraform not able to do everything this does? I was aware of something from AWS called CloudFormation templates or something but I heard that was too low-level and idiosyncratic, also JSON-based and not expressive enough. Sorry if this is a bit confused, just want some clarification, and thought that Terraform was the gold standard.

Terraform is using a delarative DSL. CloudFormation is similar in that regard.

Using a declarative language is both a pro and con.

Pros of that solution is that you are restricted in what you can do, which often results in simplier and cleaner code.

Cons are that again you are restricted in what you can do.

Now about CDK is just your preferred language library to write infrastructure in imperative way. For example you write java code that deploys infrastructure.

When using a real programming language you have ofcourse a lot more freedom in what you do, but ofcourse that comes at the cost of complexity. If your developers are “creative” it can be very hard to understand wth is happening in code.

—- So yes many ppl consider Terraform as a golden standard (me included) but after many years of working with it, like anything in IT it has own flaws and you may want to consider other solutions for specific projects.

I'm a huge fanboy of CDK. I think its superior, and that its power has yet to be realized by the tech community at large. You can essentially create object oriented abstractions of common infrastructure patterns. You are correct, you need to be careful about how you build things, but it can be extremely productive. Cloudformation is a nightmare.

CDK is also declarative - it generates a CloudFormation YAML file, so cannot possibly be anything else. Declarative is a property of a programming model, not a language.

Inbetween using CDK and generating CF Template you can be very “creative”, thats where the imperative part lies.

I think there's a much stronger argument that cloudformation deploying your stacks gets to being imperative than the way you produce your cloudformation file.

The file is still declarative regardless, and the functions you write to create that file don't per se have side effects outside that file

It’s possible, and very easy, to generate yaml with a bunch of for-loops and side-effects in an imperative language.

So without knowing anything about cdk, even if it is declarative, I don’t think your conclusion is applicable.

Terraform, the language, works differently. While it has variables, you can not store state in variables and depend on side effects based on the order you read/write such variables. Every assignment and execution order of resources is purely based on dependency order and not based on the order of the lines in your code.

Terraform is not a language. HCL could be considered a language, but really requires the additional context of the Terraform resource model and the individual schema pertaining to the resources under management to decode. It populates an internal resource model, before changes are effected by the Terraform core engine.

One can configure the self same resource model using JSON, which can be trivially generated - as you correctly point out - using whatever language and paradigm you like.

However, since the language doing the generation does not influence the order of operations when applying the effects, the model is declarative. This is identical to the CDK configuring the CloudFormation engine via YAML. Indeed, there is a CDK for Terraform too...

- CloudFormation is the native offering from AWS. Templates are submitted in the form of YAML or JSON documents.

- CDK compiles Typescript and other languages down to CloudFormation Templates

- Terraform uses the AWS API directly via an AWS-specific provider, and does not typically use CloudFormation stacks (though this can be useful, in some circumstances!)

- Pulumi uses TypeScript and other languages to drive an engine similar to Terraform (and the Terraform AWS provider is one of the options for provisioning AWS resources).

Hopefully this clears it up?

I'd recommend learning raw cloudformation first since it's the primitive cdk compiles to & being able to read/understand it will give someone full confidence of their stack.

This is how I learned. Its a great point, might be tedious to do at this point though

If you are looking for a guide on building full-stack apps on AWS, check out: https://serverless-stack.com/guide.html

It covers a small subset of AWS services but it is very comprehensive in what it covers.

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