Learning terraform with OCI provider and Oracle always free tier

Provider: OCI

https://www.terraform.io/docs/providers/oci/index.html

1. Initial terraform plugins.
2. Setup connection credentials as input variables, such various ocids, public keys etc.
3. The way of using .tfvars file is deprecated.
4. The way of configuring via SDK/CLI configuration file ~/.oci/config does not work.
5. Shell variables work as expected.
6. An exist oci resource, such as vcn, must be removed before always free configuration can be applied.
7. OCI stacks is actually implemented with terraform. There's terraform specific functions in stack's detail panel. Such as terraform configuration download (as a zip), plan, apply, destroy.
8. Long way to go as OCI api is rich and complex.