Commit Graph

2 Commits

Author SHA1 Message Date
Martin Atkins c20f25a10e moduledeps: Module.Equals
Compares two modules for deep equality. This is primarily provided to
enable easy testing of code that constructs module tree structures.
2017-06-09 14:03:59 -07:00
Martin Atkins e89b5390ca moduledeps: new package for representing module dependencies
As we add support for versioned providers, it's getting more complex to
track the dependencies of each module and of the configuration as a whole,
so this new package is intended to give us some room to model that
nicely as a building block for the various aspects of dependency
management.

This package is not responsible for *building* the dependency data
structure, since that requires knowledge of core Terraform and that would
create cyclic package dependencies. A later change will add some logic
in Terraform to create a Module tree based on the combination of a given
configuration and state, returning an instance of this package's Module
type.

The Module.PluginRequirements method flattens the provider-oriented
requirements into a set of plugin-oriented requirements (flattening any
provider aliases) giving us what we need to work with the plugin/discovery
package to find matching installed plugins.

Other later uses of this package will include selecting plugin archives
to auto-install from releases.hashicorp.com as part of "terraform init",
where the module-oriented level of abstraction here should be useful for
giving users good, specific feedback when constraints cannot be met.

A "reason" is tracked for each provider dependency with the intent that
this would later drive a UI for users to see and understand why a given
dependency is present, to aid in debugging sticky issues with
dependency resolution.
2017-06-09 14:03:59 -07:00