This refactors the engine so all of the APIs on it are instance
methods on the type instead of raw methods that float around and use
data from a global engine.
A mechcanical change as we remove the global `E` and then make
anything that interacted with that in pkg/engine to be an instance
method and the dealing with the fallout.
The plan is to take all the logic that actually implements the
commands exposed by `lumi` into a helper type that can be used by both
`lumi` and the Pulumi Service. This is step one, which was to decouple
the implementation of these commands from the command line parsing and
CLI interface they are presented to the user from.
We are renaming Lumi to Pulumi Fabric. This change simply renames the
pulumi/lumi repo to pulumi/pulumi-fabric, without the CLI tools and other
changes that will follow soon afterwards.
This change restructures a lot more pertaining to deployments, snapshots,
environments, and the like.
The most notable change is that the notion of a deploy.Source is introduced,
which splits the responsibility between the deploy.Plan -- which simply
understands how to compute and carry out deployment plans -- and the idea
of something that can produce new objects on-demand during deployment.
The primary such implementation is evalSource, which encapsulates an
interpreter and takes a package, args, and config map, and proceeds to run
the interpreter in a distinct goroutine. It synchronizes as needed to
poke and prod the interpreter along its path to create new resource objects.
There are two other sources, however. First, a nullSource, which simply
refuses to create new objects. This can be handy when writing isolated
tests but is also used to simulate the "empty" environment as necessary to
do a complete teardown of the target environment. Second, a fixedSource,
which takes a pre-computed array of objects, and hands those, in order, to
the planning engine; this is mostly useful as a testing technique.
Boatloads of code is now changed and updated in the various CLI commands.
This further chugs along towards pulumi/lumi#90. The end is in sight.
This is a minor refactoring to introduce a ProviderHost interface
that is associated with the context and can be swapped in and out for
custom plugin behavior. This is required to write tests that mock
certain aspects, like loading packages from the filesystem.
In theory, this change incurs zero behavioral changes.
