Adopt tflog

[bendbennett]

Closes #245

[bendbennett]

@bflad given hashicorp/terraform-plugin-log#52, I'm assuming the changes in this PR will not yield the desired results as context.TODO() is being used. Can you suggest how logging should be handled as the SDK documentation indicates that MigrateState should remain in place for compatibility with existing state?

[detro]

I might be wrong, but I think you essentially don't have to setup context.Context ever: as long as you use the interfaces and types that provide you with a context (and yes, will need to move from MigrateState to StateUpgraders), you can then pass that context to tflog.* calls.

Additionally, I'm planning to make use of the "subsystem facility" like here https://pkg.go.dev/github.com/hashicorp/terraform-plugin-log/tflog#SubsystemDebug - for example, each resource could be considered a subsystem.

[bendbennett]

Thanks for the link to subsystem logging.

In terms of switching to StateUpgraders, the issue is that the docs state that "Existing MigrateState implementations should remain for compatibility with existing state."

[detro]

Ah crap :(

Then let's see what @bflad thinks about the issue you highlighted above.

[bendbennett]

Closing as:

• The state migration will be going away when the random provider is migrated from sdk/v2 to the framework.
• The old MigrateState functions do not have the appropriate logging context available from the sdk.
• tflog will drop logs that don’t have an appropriate logging context until Fallback to Generic Logger Output is done.