feat(ske): add datasource to query provider options

[h3adex]

Description

This PR adds the ske options API as datasource to query kubernetes and machine versions. Currently the API does not support any filtering option, but this can be done in the meanwhile using terraform locals. Example code is in the generated docs.

data "stackit_ske_provider_options" "this" {}

locals {
  k8s_versions = [
    for v in data.stackit_ske_provider_options.this.kubernetes_versions :
    v.version if v.state == "supported"
  ]
  first_k8s_version = length(local.k8s_versions) > 0 ? local.k8s_versions[0] : ""
  last_k8s_version = length(local.k8s_versions) > 0 ? local.k8s_versions[length(local.k8s_versions) - 1] : ""


  flatcar_supported_versions = flatten([
    for mi in data.stackit_ske_provider_options.this.machine_images : [
      for v in mi.versions :
      v.version if mi.name == "flatcar" && v.state == "supported"
    ]
  ])

  ubuntu_supported_versions = flatten([
    for mi in data.stackit_ske_provider_options.this.machine_images : [
      for v in mi.versions :
      v.version if mi.name == "ubuntu" && v.state == "supported"
    ]
  ])
}

output "first_k8s_version" {
  value = local.first_k8s_version
}

output "last_k8s_version" {
  value = local.last_k8s_version
}

output "k8s_versions" {
  value = local.k8s_versions
}

output "ubuntu_supported_version" {
  value = local.ubuntu_supported_versions[0]
}

output "flatcar_supported_version" {
  value = local.flatcar_supported_versions[0]
}

Checklist

• Issue was linked above
• Code format was applied: make fmt
• Examples were added / adjusted (see examples/ directory)
• Docs are up-to-date: make generate-docs (will be checked by CI)
• Unit tests got implemented or updated
• Acceptance tests got implemented or updated (see e.g. here)
• Unit tests are passing: make test (will be checked by CI)
• No linter issues: make lint (will be checked by CI)

[hown3d]

Even if the API does not allow for filtering at the moment, we should still support filtering in the terraform go code.
Using locals may be possible, but is not a nice API and not something I want to recommend.

[hown3d]

Closes #953

[rubenhoenle]

The list provider options endpoint returns a lot of different information.

I wouldn't combine all of this into a single datasource, instead I would create multiple datasources here. (IMO there should be also multiple endpoints for listing k8s versions, listing machine types, ... but that's another discussion.)

So I would suggest

• datasource stackit_ske_kubernetes_versions
• datasource stackit_ske_machine_types
• datasource stackit_ske_volume_types
• ...

[github-actions]

This PR was marked as stale after 7 days of inactivity and will be closed after another 7 days of further inactivity. If this PR should be kept open, just add a comment, remove the stale label or push new commits to it.

[h3adex]

@rubenhoenle

I've just implemented your suggestion. While some work remains, could you please verify if this approach is heading in the right direction? I've split the functionality into 5 different data sources:

stackit_ske_kubernetes_versions
stackit_ske_machine_image_versions

Will also get the versionState flag once it is merged into the go-sdk:
https://docs.api.stackit.cloud/documentation/ske/version/v2#tag/ProviderOptions
stackitcloud/stackit-sdk-go#3786

I haven't yet identified a customer use case for the stackit_ske_volume_type data source. I'll reach out to our SKE team to request that they provide IOPS data through the API, allowing customers to filter volume names based on IOPS.