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Out of interest, do you find yourself writing actual software with CDK stacks integrated, or is it more accurate to say the CDK is just a stand-alone bit of cod

Out of interest, do you find yourself writing actual software with CDK stacks integrated, or is it more accurate to say the CDK is just a stand-alone bit of code purely for deploying infrastructure? I'm definitely in the latter camp, which is something I find frustrating. I get that for a developer the syntax familiarity might make CDK easier, but for me as a non-developer the pain of groping around the terrible documentation and learning how classes are supposed to be used far outweighs the annoyance of fixing YAML indentation. Ultimately I worry people are jumping on the "true IaC" bandwagon without acknowledging that if their infrastructure is supposed to be somewhat static and immutable, a declarative language might actually be better.

rkeene2 5y ago
For one of my projects I use CDK (JS) with a JavaScript project and the CDK part does call limited parts of the project to lookup how many DynamDB tables to create and which kinds of which indexes to generate. Also the API gateway configuration is generated based on registered endpoints within a larger application, but that's not being done directly in the CDK, but as a separate explicit step in the Makefile as a dependency of the CDK targets. Disclaimer: I work for AWS, but not on anything related to this, other than using it.
throwaway894345 5y ago
I strongly suspect that these CDKs are not very well designed. In particular, what I want is something that lets me generate YAML/etc in a type-safe fashion. That YAML is then the input for an engine which reconciles the desired state with the actual state (a la Terraform or cloudFormation). The idea is that the “real programming language” layer just allows us to DRY our YAML. For a use case like this, we don’t need inheritance or methods, but just structs, maps, arrays, and functions; however, these CDKs typically index pretty hard on inheritance and generally make things more complicated than necessary.
- AstroDogCatcher 5y ago
  That is certainly my impression with CDK. An even bigger heartache is the fact that I am writing a Python "program", but then have to use a JS binary to execute the deployment. Having the CDK synth/deploy functionality exposed via actual execution of the Python script (or even a built-in capability of the regular AWS CLI) would make much more sense to me.
- toiletduck 5y ago
  Your suspicions are incorrect - I'd suggest trying the AWS CDK as it solves exactly the problem you want it to solve in the sense of providing strong type safety.
  - throwaway894345 5y ago
    My only experience is with the AWS CDK.
- hnlmorg 5y ago
  It's important to note that Terraform doesn't compile down to CloudFormation stacks like CDK does. Terraform providers instead call AWS APIs directly. This should allow Terraform much more composability than CDK for the very points you've listed unfortunately Terraform does still compile down to a fucking JSON state -- which is easily my biggest complaint about Terraform. My issue with anything that ultimately compiles to a JSON or YAML state/config is that you lose the dependency tree (or your dependency tree becomes rigidly defined by the way the transpiler converts your code into JSON). It causes so many problems on any large project that ultimately the only solution is to break the project up into smaller distinct projects within the same git repository. Which is basically the same solution to working with JSON/YAML CF stacks directly. If someone can create a language (or SDK for $PROGRAMMING_LANG) that then worked with AWS APIs directly, (like Terraform), didn't just transpile back to JSON, and isn't as verbose as using boto3 directly -- well I think that product might stand a real chance of displacing Terraform. I've got a lot of strong thoughts on how this could be done right so I did consider having an attempt at it myself using the shell scripting language I'd designed as a rough foundation. But having a full time job already, two young kids, and a growing in popularity open source project (namely my aforementioned $SHELL), I realised any Terraform competitor I did create would be doomed to either never being maintained, or the project would literally burn me out.
  - throwaway894345 5y ago
    Neither system deals well with large projects, but my CF criticisms weren’t predicated on the project size. So at the end of the day, CF has all of the problems TF has and then some. But I do think that it would be really interesting to build an IaC project, and you’re right that it probably would be doomed. :)

rkeene2 5y ago

For one of my projects I use CDK (JS) with a JavaScript project and the CDK part does call limited parts of the project to lookup how many DynamDB tables to create and which kinds of which indexes to generate. Also the API gateway configuration is generated based on registered endpoints within a larger application, but that's not being done directly in the CDK, but as a separate explicit step in the Makefile as a dependency of the CDK targets. Disclaimer: I work for AWS, but not on anything related to this, other than using it.

throwaway894345 5y ago

I strongly suspect that these CDKs are not very well designed. In particular, what I want is something that lets me generate YAML/etc in a type-safe fashion. That YAML is then the input for an engine which reconciles the desired state with the actual state (a la Terraform or cloudFormation). The idea is that the “real programming language” layer just allows us to DRY our YAML. For a use case like this, we don’t need inheritance or methods, but just structs, maps, arrays, and functions; however, these CDKs typically index pretty hard on inheritance and generally make things more complicated than necessary.

AstroDogCatcher 5y ago
That is certainly my impression with CDK. An even bigger heartache is the fact that I am writing a Python "program", but then have to use a JS binary to execute the deployment. Having the CDK synth/deploy functionality exposed via actual execution of the Python script (or even a built-in capability of the regular AWS CLI) would make much more sense to me.
toiletduck 5y ago
Your suspicions are incorrect - I'd suggest trying the AWS CDK as it solves exactly the problem you want it to solve in the sense of providing strong type safety.
- throwaway894345 5y ago
  My only experience is with the AWS CDK.
hnlmorg 5y ago
It's important to note that Terraform doesn't compile down to CloudFormation stacks like CDK does. Terraform providers instead call AWS APIs directly. This should allow Terraform much more composability than CDK for the very points you've listed unfortunately Terraform does still compile down to a fucking JSON state -- which is easily my biggest complaint about Terraform. My issue with anything that ultimately compiles to a JSON or YAML state/config is that you lose the dependency tree (or your dependency tree becomes rigidly defined by the way the transpiler converts your code into JSON). It causes so many problems on any large project that ultimately the only solution is to break the project up into smaller distinct projects within the same git repository. Which is basically the same solution to working with JSON/YAML CF stacks directly. If someone can create a language (or SDK for $PROGRAMMING_LANG) that then worked with AWS APIs directly, (like Terraform), didn't just transpile back to JSON, and isn't as verbose as using boto3 directly -- well I think that product might stand a real chance of displacing Terraform. I've got a lot of strong thoughts on how this could be done right so I did consider having an attempt at it myself using the shell scripting language I'd designed as a rough foundation. But having a full time job already, two young kids, and a growing in popularity open source project (namely my aforementioned $SHELL), I realised any Terraform competitor I did create would be doomed to either never being maintained, or the project would literally burn me out.
- throwaway894345 5y ago
  Neither system deals well with large projects, but my CF criticisms weren’t predicated on the project size. So at the end of the day, CF has all of the problems TF has and then some. But I do think that it would be really interesting to build an IaC project, and you’re right that it probably would be doomed. :)