Provider client connection rework

[marnas]

Client connection has been reworked following new specifications.

Both Console and Gateway connection details have been consolidated and the usage of either is defined by the addition of a new variable named mode.

Most of the Client implementation has also been refactored in the process to avoid duplication.

[qboileau]

for environment variables I think we should support the generic one like CDK_BASE_URL/CDK_ADMIN_USER/CDK_ADMIN_PASSWORD/... for both console and gateway and add fallback on specific one like CDK_CONSOLE_URL/CDK_GATEWAY_URL/CDK_CONSOLE_USER/CDK_CONSOLE_PASSWORD/CDK_GATEWAY_USER/... for the case when we have 2 instances at the same time and we don't want env var collision
WDYT ?

[marnas]

I agree with the additions proposed for the env variables but I would probably reverse the priority order from CDK_CONSOLE_URL/CDK_GATEWAY_URL first to then fall back on the generic CDK_BASE_URL.

The reasoning being to avoid collisions for someone who might get started with only one client and configure it with generic variables, to then add the other client with the relative specific without re-configuring the other client's variable.

Do you agree or would you rather enforce the usage of the specific variables in the case of multi client config?

[qboileau]

I agree with the additions proposed for the env variables but I would probably reverse the priority order from CDK_CONSOLE_URL/CDK_GATEWAY_URL first to then fall back on the generic CDK_BASE_URL.

The reasoning being to avoid collisions for someone who might get started with only one client and configure it with generic variables, to then add the other client with the relative specific without re-configuring the other client's variable.

Do you agree or would you rather enforce the usage of the specific variables in the case of multi client config?

I'm good with this proposal. Because env var might not be used in first place and reply directly on terraform provider attributes directly removing the ambiguity.

[qboileau]

LGTM