r/burn_alert: Add support for budget rate burn alerts

[lafentres]

Short description of the changes

This PR adds support for budget rate burn alerts to the burn alert resource.

How to verify that this has the expected result

Pre-requisites:

• You'll need Go 1.20 and the latest Terraform installed.
• You'll need a team in Honeycomb to test against.
• You'll need a dataset, derived column, and SLO for that team.
• You'll need an API key for that team.

Setup:

1. Create a new directory called providers somewhere you can easily access (but not inside the same folder as your Terraform config).
2. Build the provider by checking out this branch and running make build
3. Move the executable created to the providers directory you created earlier.

   mv terraform-provider-honeycombio /PATH/TO/YOUR/DIRECTORY/providers
   

4. Add the following to your ~/.terraformrc file:

   provider_installation {
   
     # Use /PATH/TO/YOUR/DIRECTORY/providers/terraform-provider-honeycombio
     # as an overridden package directory for the honeycombio/honeycombio provider. 
     # This disables the version and checksum verifications for this provider and 
     # forces Terraform to look for the null provider plugin in the given directory.
     #dev_overrides {
     #  "honeycombio/honeycombio" = "/PATH/TO/YOUR/DIRECTORY/providers"
     #}
   
     # For all other providers, install them directly from their origin provider
     # registries as normal. If you omit this, Terraform will _only_ use
     # the dev_overrides block, and so no other providers will be available.
     direct {}
   }
   

5. Create another new directory (all Terraform commands will be run in this directory)
6. Download and save this file as main.tf in your new directory. You'll be modifying it in the steps below.
7. Set the following environment variables:

   export HONEYCOMB_API_KEY=YOUR_API_KEY_HERE
   export TF_VAR_dataset=YOUR_DATASET_SLUG_HERE
   export TF_VAR_slo_id=YOUR_SLO_ID_HERE
   

8. Run terraform init.

Provision resources for r/burn_alert:

1. Run terraform apply. This should succeed and if you check in the UI, you should see the burn alerts you just created.
2. Run terraform plan. There should be no changes.

Check that upgrading provider version doesn't break anything:

1. Update your provider version to local build of this branch by editing your ~/.terraformrc file and remove the comments in front of the dev_overrides block

     dev_overrides {
       "honeycombio/honeycombio" = "/PATH/TO/YOUR/DIRECTORY/providers"
     }
   

2. Run terraform plan. This time you should see a yellow warning block telling you that development overrides are in place. It should look like this:
   

Check that validation works:

1. Uncomment the 2nd and 3rd burn alerts in your config.
2. Run terraform apply. This should succeed and if you check in the UI, you should see the 2 new burn alerts you just created.
3. Try updating each of your burn alerts to be invalid. Examples include:
   • Invalid alert_type
   • Exhaustion time alert without exhaustion_minutes specified
   • Exhaustion time alert with exhaustion_minutes < 0
   • Exhaustion time alert with budget rate fields specified
   • Budget rate alert without budget rate fields specified
   • Budget rate alert with budget_rate_window_minutes < 60 or > the SLO's time period
   • Budget rate alert with budget_rate_decrease_percent < 0.0001 or > 100
   • Budget rate alert with budget_rate_decrease_percent with more than 4 non-zero digits past the decimal
   • Budget rate alert with exhaustion_minutes specified
4. Run terraform apply. This should fail and you should see descriptive errors about what attributes have been misconfigured.
5. Undo any changes to your config before moving on

Check that updating burn alerts works:

1. Update each of your burn alerts by changing any valid combo of alert_type, exhaustion_minutes, budget_rate_window_minutes, or budget_rate_decrease_percent. Examples of useful scenarios to test out:
   • Exhaustion time alert to a budget rate alert
   • Budget rate alert to an exhaustion time alert
   • Budget rate burn alert to an exhaustion time burn alert without specifying the alert_type
   • Exhaustion time alert to have exhaustion_minutes = 0
2. Run terraform apply. The output should show the changes you made in the config. After confirming, you should see these changes reflected in the UI.
3. Run terraform plan. Your plan should show no changes.

Check that destroy works

1. Run terraform destroy. This should succeed. You should see these changes reflected in the UI.

Check that a fresh create works

1. Run terraform apply. This should succeed. You should see these changes reflected in the UI.

Related links

• API documentation

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 97.82609% with 5 lines in your changes missing coverage. Please review.

Project coverage is 80.82%. Comparing base (5068dc5) to head (f6ebbc7).
Report is 130 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/provider/burn_alert_resource.go	98.39%	2 Missing and 1 partial ⚠️
internal/helper/validation/precision_at_most.go	93.33%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #391      +/-   ##
==========================================
+ Coverage   80.81%   80.82%   +0.01%     
==========================================
  Files          56       62       +6     
  Lines        4565     4809     +244     
==========================================
+ Hits         3689     3887     +198     
- Misses        722      768      +46     
  Partials      154      154              

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[jharley]

Just took another quick pass, but this is coming together great. Thanks for the care in crafting such thorough tests

[jharley]

✨

[jharley]

🚀