If a configuration requires a partial provider version (with some parts
unspecified), Terraform considers this as a constrained-to-zero version.
For example, a version constraint of 1.2 will result in an attempt to
install version 1.2.0, even if 1.2.1 is available.
When writing the dependency locks file, we previously would write 1.2.*,
as this is the in-memory representation of 1.2. This would then cause an
error on re-reading the locks file, as this is not a valid constraint
format.
Instead, we now explicitly convert the constraint to its zero-filled
representation before writing the locks file. This ensures that it
correctly round-trips.
Because this change is made in getproviders.VersionConstraintsString, it
also affects the output of the providers sub-command.
Previously we were just letting hclwrite do its default formatting
behavior here. The current behavior there isn't ideal anyway -- it puts
big data structures all on one line -- but even ignoring that our goal
for this file format is to keep things in a highly-normalized shape so
that diffs against the file are clear and easy to read.
With that in mind, here we directly control how we write that value into
the file, which means that later changes to hclwrite's list/set
presentation won't affect it, regardless of what form they take.
The logic for what constitutes a valid hash and how different hash schemes
are represented was starting to get sprawled over many different files and
packages.
Consistently with other cases where we've used named types to gather the
definition of a particular string into a single place and have the Go
compiler help us use it properly, this introduces both getproviders.Hash
representing a hash value and getproviders.HashScheme representing the
idea of a particular hash scheme.
Most of this changeset is updating existing uses of primitive strings to
uses of getproviders.Hash. The new type definitions are in
internal/getproviders/hash.go.
Although origin registries return specific [filename, hash] pairs, our
various different installation methods can't produce a structured mapping
from platform to hash without breaking changes.
Therefore, as a compromise, we'll continue to do platform-specific checks
against upstream data in the cases where that's possible (installation
from origin registry or network mirror) but we'll treat the lock file as
just a flat set of equally-valid hashes, at least one of which must match
after we've completed whatever checks we've made against the
upstream-provided checksums/signatures.
This includes only the minimal internal/getproviders updates required to
make this compile. A subsequent commit will update that package to
actually support the idea of verifying against multiple hashes.
This is an initial implementation of writing locks back to a file on disk.
This initial implementation is incomplete because it does not write the
changes to the new file atomically. We'll revisit that in a later commit
as we return to polish these codepaths, once we've proven out this
package's design by integrating it with Terraform's provider installer.
This is the initial implementation of the parser/decoder portion of the
new dependency lock file handler. It's currently dead code because the
caller isn't written yet. We'll continue to build out this functionality
here until we have the basic level of both load and save functionality
before introducing this into the provider installer codepath.
Alisdair McDiarmid