[FEATURE] Detect workspace/account config upon construction of a client

[ShripadMhetre]

Issue fixed - #552

Changes

In workspace_client.go, added the conditional check to catch if account profile is being passed to instantiate WorkspaceClient.

Tests

• make test passing
• make fmt applied
• [] relevant integration tests applied

[nfx]

this will not work with Terraform, as sometimes we know host only after upstream modules are initialized.

we can't deterministically give this kind of error on the level of NewWorkspaceClient

[nfx]

this will not work with Terraform, as sometimes we know host only after upstream modules are initialized.

[ShripadMhetre]

Similar kind of check exist in account_client.go -

if cfg.AccountID == "" || !cfg.IsAccountClient() {
	return nil, ErrNotAccountClient
}

Can you help me understand the optimal solution then? to make it work with Terraform as well.
Also, should I add the call to cfg.EnsureResolved() as well before cfg.IsAccountClient() check?

[nfx]

terraform resolves config upon the first request

[ShripadMhetre]

Please review the latest changes and help with proper feedback

[nfx]

it is not enough, proper implementation should be lazy evaluated - e.g. after the error. otherwise this will break certain terraform workflows, where account id is not yet available and is loaded from another resource

[pietern]

For posterity, what was missing here was a call to EnsureResolved on the config.

The lazy initialization in TF is handled by the TF provider itself: https://github.com/databricks/terraform-provider-databricks/blob/eeb453e5c41a71466a762f9145eca6d90124700b/provider/provider.go#L202-L247

That's where it pulls the current values from the provider configuration block, populates a config.Config object, and constructs a client through client.New. Then later the config field from that client is used to construct a workspace client or an account client (see common/client.go).

This is fixed by #596.