feat(tfe_saml_settings): add resource

[karvounis-form3]

Description

This PR adds the resource tfe_saml_settings. This change is required in order to add SAML settings support to the provider (documentation).

Closes: #819

Testing plan

1. The minimal configuration is as below:

provider "tfe" {}

resource "tfe_saml_settings" "this" {
  idp_cert                      = "idp_certTerraformExample"
  slo_endpoint_url              = "https://example.com/slo_endpoint_url"
  sso_endpoint_url              = "https://example.com/sso_endpoint_url"
}

2. Run terraform apply - resources will be created successfully.
3. Update the resource to the following:

provider "tfe" {}

resource "tfe_saml_settings" "this" {
  idp_cert                      = "idp_certTerraformExample"
  slo_endpoint_url              = "https://example-updated.com/slo_endpoint_url"
  sso_endpoint_url              = "https://example-updated.com/sso_endpoint_url"
  sso_api_token_session_timeout = "1444444"
  certificate                   = "exampleCert"
  private_key                   = "examplePrivateKey"
  signature_digest_method       = "SHA1"
  attr_username                 = "FooUsername"
  authn_requests_signed         = true
}

4. Run terraform apply again. It will update the attributes already created (idp_cert, slo_endpoint_url, sso_endpoint_url) and set the values for the new attributes defined (sso_api_token_session_timeout, certificate, private_key, signature_digest_method, attr_username, authn_requests_signed,).
5. Run terraform destroy. It will remove the resource from the state, disable the SAML single sign-on and set all the values to the default ones.

External links

• Update SAML settings API
• go-tfe v1.30.0

Output from acceptance tests

$ TESTARGS="-run TestAccTFESAMLSettings" make testacc

TF_ACC=1 TF_LOG_SDK_PROTO=OFF go test $(go list ./... |grep -v 'vendor') -v -run TestAccTFESAMLSettings -timeout 15m
?   	github.com/hashicorp/terraform-provider-tfe	[no test files]
=== RUN   TestAccTFESAMLSettingsDataSource_basic
--- PASS: TestAccTFESAMLSettingsDataSource_basic (15.51s)
=== RUN   TestAccTFESAMLSettings_basic
--- PASS: TestAccTFESAMLSettings_basic (17.52s)
=== RUN   TestAccTFESAMLSettings_full
--- PASS: TestAccTFESAMLSettings_full (17.40s)
=== RUN   TestAccTFESAMLSettings_update
--- PASS: TestAccTFESAMLSettings_update (29.98s)
=== RUN   TestAccTFESAMLSettings_import
--- PASS: TestAccTFESAMLSettings_import (20.63s)
PASS
ok  	github.com/hashicorp/terraform-provider-tfe/tfe	102.966s
?   	github.com/hashicorp/terraform-provider-tfe/version	[no test files]

[uturunku1]

testing on : #971

[karvounis-form3]

@uturunku1 can you please trigger the tests again?

[uturunku1]

Thanks for following through on this!
There is one test failure to address:

I have used the documentation that you linked in the PR to compare and contrast with the settings that are adding here, and so far your implementation looks accurate!
Now with all your changes put together, I'd like to a smoke test the whole workflow for this feature. Would you mind adding a Testing Plan section in the PR description that includes instructions (a tf config sample, etc) on how to smoke test for this new feature? 🙏

[karvounis-form3]

@uturunku1 Thanks for reviewing the PR! I updated the ticket description with a test plan. Does that work for you? Let me know if I need to add anything else.

[uturunku1]

Works as expected! 🎉 I also verify the changes were reflected in the platform's UI. Thank you @karvounis-form3 for making quick adjustments to the test failures, and all your effort in general! 🏆