This is a stepping-stone PR for the provider source project. In this PR
"legcay-stype" FQNs are created from the provider name string. Future
work involves encoding the FQN directly in the AbsProviderConfig and
removing the calls to addrs.NewLegacyProvider().
* Introduce "Local" terminology for non-absolute provider config addresses
In a future change AbsProviderConfig and LocalProviderConfig are going to
become two entirely distinct types, rather than Abs embedding Local as
written here. This naming change is in preparation for that subsequent
work, which will also include introducing a new "ProviderConfig" type
that is an interface that AbsProviderConfig and LocalProviderConfig both
implement.
This is intended to be largely just a naming change to get started, so
we can deal with all of the messy renaming. However, this did also require
a slight change in modeling where the Resource.DefaultProviderConfig
method has become Resource.DefaultProvider returning a Provider address
directly, because this method doesn't have enough information to construct
a true and accurate LocalProviderConfig -- it would need to refer to the
configuration to know what this module is calling the provider it has
selected.
In order to leave a trail to follow for subsequent work, all of the
changes here are intended to ensure that remaining work will become
obvious via compile-time errors when all of the following changes happen:
- The concept of "legacy" provider addresses is removed from the addrs
package, including removing addrs.NewLegacyProvider and
addrs.Provider.LegacyString.
- addrs.AbsProviderConfig stops having addrs.LocalProviderConfig embedded
in it and has an addrs.Provider and a string alias directly instead.
- The provider-schema-handling parts of Terraform core are updated to
work with addrs.Provider to identify providers, rather than legacy
strings.
In particular, there are still several codepaths here making legacy
provider address assumptions (in order to limit the scope of this change)
but I've made sure each one is doing something that relies on at least
one of the above changes not having been made yet.
* addrs: ProviderConfig interface
In a (very) few special situations in the main "terraform" package we need
to make runtime decisions about whether a provider config is absolute
or local.
We currently do that by exploiting the fact that AbsProviderConfig has
LocalProviderConfig nested inside of it and so in the local case we can
just ignore the wrapping AbsProviderConfig and use the embedded value.
In a future change we'll be moving away from that embedding and making
these two types distinct in order to represent that mapping between them
requires consulting a lookup table in the configuration, and so here we
introduce a new interface type ProviderConfig that can represent either
AbsProviderConfig or LocalProviderConfig decided dynamically at runtime.
This also includes the Config.ResolveAbsProviderAddr method that will
eventually be responsible for that local-to-absolute translation, so
that callers with access to the configuration can normalize to an
addrs.AbsProviderConfig given a non-nil addrs.ProviderConfig. That's
currently unused because existing callers are still relying on the
simplistic structural transform, but we'll switch them over in a later
commit.
* rename LocalType to LocalName
Co-authored-by: Kristin Laemmert <mildwonkey@users.noreply.github.com>
Following the same approach we use for other CLI-Config-able objects like
the service discovery system, the main package is responsible for
producing a suitable implementation of this interface which the command
package can then use.
When unit testing in the command package we can then substitute mocks as
necessary, following the dependency inversion principle.
This is a temporary helper so that we can potentially ship the new
provider installer without making a breaking change by relying on the
old default namespace lookup API on the default registry to find a proper
FQN for a legacy provider provider address during installation.
If it's given a non-legacy provider address then it just returns the given
address verbatim, so any codepath using it will also correctly handle
explicit full provider addresses. This also means it will automatically
self-disable once we stop using addrs.NewLegacyProvider in the config
loader, because there will therefore no longer be any legacy provider
addresses in the config to resolve. (They'll be "default" provider
addresses instead, assumed to be under registry.terraform.io/hashicorp/* )
It's not decided yet whether we will actually introduce the new provider
in a minor release, but even if we don't this API function will likely be
useful for a hypothetical automatic upgrade tool to introduce explicit
full provider addresses into existing modules that currently rely on
the equivalent to this lookup in the current provider installer.
This is dead code for now, but my intent is that it would either be called
as part of new provider installation to produce an address suitable to
pass to Source.AvailableVersions, or it would be called from the
aforementioned hypothetical upgrade tool.
Whatever happens, these functions can be removed no later than one whole
major release after the new provider installer is introduced, when
everyone's had the opportunity to update their legacy unqualified
addresses.
Alisdair McDiarmid