These were being used in an earlier iteration of the provider installation
configuration but it was all collapsed down into a single
ProviderInstallationMethod type later, making these redundant.
When we originally introduced this environment variable it was intended to
solve for the use-case where a particular invocation of Terraform needs
a different CLI configuration than usual, such as if Terraform is being
run as part of an automated test suite or other sort of automated
situation with different needs than normal use.
However, we accidentally had it only override the original singleton CLI
config file, while leaving the CLI configuration directory still enabled.
Now we'll take the CLI configuration out of the equation too, so that only
the single specified configuration file and any other environment-sourced
settings will be included.
This new CLI config block type allows explicitly specifying where
Terraform should look to find provider plugins for installation. This is
not used anywhere as of this commit, but in a future commit we'll change
package main to treat the presence of a block of this type as a request
to disable the default set of provider sources and use these explicitly-
specified ones instead.
This was a leftover from the migration of these types from the main
package, but we don't actually need or want this here because this
particular detail is still handled by the main package, and because the
cliconfig package must not depend on the command package in order to avoid
an import cycle.
This is just a wholesale move of the CLI configuration types and functions
from the main package into its own package, leaving behind some type
aliases and wrappers for now to keep existing callers working.
This commit alone doesn't really achieve anything, but in future commits
we'll expand the functionality in this package.
Martin Atkins