5 Commits (2edd9f4e10faf38e65d5fc5ce4e29c3c4e3b59b0)

Author	SHA1	Message	Date
Martin Atkins	df578afd7e	backend/local: Check dependency lock consistency before any operations ... In historical versions of Terraform the responsibility to check this was inside the terraform.NewContext function, along with various other assorted concerns that made that function particularly complicated. More recently, we reduced the responsibility of the "terraform" package only to instantiating particular named plugins, assuming that its caller is responsible for selecting appropriate versions of any providers that _are_ external. However, until this commit we were just assuming that "terraform init" had correctly selected appropriate plugins and recorded them in the lock file, and so nothing was dealing with the problem of ensuring that there haven't been any changes to the lock file or config since the most recent "terraform init" which would cause us to need to re-evaluate those decisions. Part of the game here is to slightly extend the role of the dependency locks object to also carry information about a subset of provider addresses whose lock entries we're intentionally disregarding as part of the various little edge-case features we have for overridding providers: dev_overrides, "unmanaged providers", and the testing overrides in our own unit tests. This is an in-memory-only annotation, never included in the serialized plan files on disk. I had originally intended to create a new package to encapsulate all of this plugin-selection logic, including both the version constraint checking here and also the handling of the provider factory functions, but as an interim step I've just made version constraint consistency checks the responsibility of the backend/local package, which means that we'll always catch problems as part of preparing for local operations, while not imposing these additional checks on commands that _don't_ run local operations, such as "terraform apply" when in remote operations mode.	5 years ago
Martin Atkins	80b3fcf93e	core: Replace contextComponentFactory with contextPlugins ... In the v0.12 timeframe we made contextComponentFactory an interface with the expectation that we'd write mocks of it for tests, but in practice we ended up just always using the same "basicComponentFactory" implementation throughout. In the interests of simplification then, here we replace that interface and its sole implementation with a new concrete struct type contextPlugins. Along with the general benefit that this removes an unneeded indirection, this also means that we can add additional methods to the struct type without the usual restriction that interface types prefer to be small. In particular, in a future commit I'm planning to add methods for loading provider and provisioner schemas, working with the currently-unused new fields this commit has included in contextPlugins, as compared to its predecessor basicComponentFactory.	5 years ago
Martin Atkins	89b05050ec	core: Functional-style API for terraform.Context ... Previously terraform.Context was built in an unfortunate way where all of the data was provided up front in terraform.NewContext and then mutated directly by subsequent operations. That made the data flow hard to follow, commonly leading to bugs, and also meant that we were forced to take various actions too early in terraform.NewContext, rather than waiting until a more appropriate time during an operation. This (enormous) commit changes terraform.Context so that its fields are broadly just unchanging data about the execution context (current workspace name, available plugins, etc) whereas the main data Terraform works with arrives via individual method arguments and is returned in return values. Specifically, this means that terraform.Context no longer "has-a" config, state, and "planned changes", instead holding on to those only temporarily during an operation. The caller is responsible for propagating the outcome of one step into the next step so that the data flow between operations is actually visible. However, since that's a change to the main entry points in the "terraform" package, this commit also touches every file in the codebase which interacted with those APIs. Most of the noise here is in updating tests to take the same actions using the new API style, but this also affects the main-code callers in the backends and in the command package. My goal here was to refactor without changing observable behavior, but in practice there are a couple externally-visible behavior variations here that seemed okay in service of the broader goal: - The "terraform graph" command is no longer hooked directly into the core graph builders, because that's no longer part of the public API. However, I did include a couple new Context functions whose contract is to produce a UI-oriented graph, and _for now_ those continue to return the physical graph we use for those operations. There's no exported API for generating the "validate" and "eval" graphs, because neither is particularly interesting in its own right, and so "terraform graph" no longer supports those graph types. - terraform.NewContext no longer has the responsibility for collecting all of the provider schemas up front. Instead, we wait until we need them. However, that means that some of our error messages now have a slightly different shape due to unwinding through a differently-shaped call stack. As of this commit we also end up reloading the schemas multiple times in some cases, which is functionally acceptable but likely represents a performance regression. I intend to rework this to use caching, but I'm saving that for a later commit because this one is big enough already. The proximal reason for this change is to resolve the chicken/egg problem whereby there was previously no single point where we could apply "moved" statements to the previous run state before creating a plan. With this change in place, we can now do that as part of Context.Plan, prior to forking the input state into the three separate state artifacts we use during planning. However, this is at least the third project in a row where the previous API design led to piling more functionality into terraform.NewContext and then working around the incorrect order of operations that produces, so I intend that by paying the cost/risk of this large diff now we can in turn reduce the cost/risk of future projects that relate to our main workflow actions.	5 years ago
Martin Atkins	31349a9c3a	Move configs/ to internal/configs/ ... This is part of a general effort to move all of Terraform's non-library package surface under internal in order to reinforce that these are for internal use within Terraform only. If you were previously importing packages under this prefix into an external codebase, you could pin to an earlier release tag as an interim solution until you've make a plan to achieve the same functionality some other way.	5 years ago
Martin Atkins	ffe056bacb	Move command/ to internal/command/ ... This is part of a general effort to move all of Terraform's non-library package surface under internal in order to reinforce that these are for internal use within Terraform only. If you were previously importing packages under this prefix into an external codebase, you could pin to an earlier release tag as an interim solution until you've make a plan to achieve the same functionality some other way.	5 years ago