* internal/getproviders: decode and return any registry warnings
The public registry may include a list of warnings in the "versions"
response for any given provider. This PR adds support for warnings from
the registry and an installer event to return those warnings to the
user.
provider is not found.
Previously a user would see the following error even if terraform was
only searching the local filesystem:
"provider registry registry.terraform.io does not have a provider named
...."
This PR adds a registry-specific error type and modifies the MultiSource
installer to check for registry errors. It will return the
registry-specific error message if there is one, but if not the error
message will list all locations searched.
Previously this was available by instantiating a throwaway
FilesystemMirrorSource, but that's pretty counter-intuitive for callers
that just want to do a one-off scan without retaining any ongoing state.
Now we expose SearchLocalDirectory as an exported function, and the
FilesystemMirrorSource then uses it as part of its implementation too.
Callers that just want to know what's available in a directory can call
SearchLocalDirectory directly.
This is a basic implementation of FilesystemMirrorSource for now aimed
only at the specific use-case of scanning the cache of provider plugins
Terraform will keep under the ".terraform" directory, as part of our
interim provider installer implementation for Terraform 0.13.
The full functionality of this will grow out in later work when we
implement explicit local filesystem mirrors, but for now the goal is to
use this just to inspect the work done by the automatic installer once
we switch it to the new provider-FQN-aware directory structure.
The various FIXME comments in this are justified by the limited intended
scope of this initial implementation, and they should be resolved by
later work to use FilesystemMirrorSource explicitly for user-specified
provider package mirrors.
In a future commit, these implementations of Source will allow finding
and retrieving provider packages via local mirrors, both in the local
filesystem and over the network using an HTTP-based protocol.
Kristin Laemmert