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50 lines
2.0 KiB
Markdown
50 lines
2.0 KiB
Markdown
# Bonus Challenge
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This part of the repo holds the bonus challenge for 2024: implement as much as possible in pure
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Terraform.
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## Usage
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The infrastructure definitions expect the input files to be located at `../inputs/[\d]{2}.txt`.
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After storing the input files there, the code should be runnable as follows:
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```console
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$ terraform init
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< a lot of modules being installed >
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$ terraform plan
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Changes to Outputs:
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+ day01_1 = 42
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+ day01_2 = 12
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+ day02_1 = …
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You can apply this plan to save these new output values to the Terraform state, without changing any real infrastructure.
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```
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Note that Terraform may freeze for tens of seconds while it's running the computations. This is
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normal, and all Terraform code ought to think a little before doing anything. It would save people
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some bad rollbacks.
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## Development
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I use [Terraform tests](https://developer.hashicorp.com/terraform/language/tests) to automatically
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run my terraform code on the sample inputs. It's almost a normal development workflow.
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The only rule is that the code should be all terraform, no cheating by shelling out to external
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programs. Using providers is allowed, as long as the providers don't actually interact with external
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systems and are reasonably self-contained. I will try to limit my use of those regardless.
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## Why
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DevOps will continue until morale improves. But really, a friend remarked that my Python solutions
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were strangely normal for me, so I opted to use a language that I do use professionally.
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Terraform is a unique beast. It can do a lot, but it is also very limited, and intentionally so.
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There's a standard library of functions you might want to use, but all of them work in strange ways
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and there isn't that much to begin with. You can never mutate any variables, you can only declare
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new ones. You don't have recursion and your only source of loops are list- and map comprehensions,
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or multiple instantiations or a module.
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These make for a very constrained programming environment, and constrained programming is fun. It
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makes you think outside the box.
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