3 Commits (eaddf9ccf13ca54b469e90feb2d444ff996fc3bf)

Author	SHA1	Message	Date
Martin Atkins	3b49028b77	core: Static-validate resource references against schemas ... In the initial move to HCL2 we started relying only on full expression evaluation to catch attribute errors, but that's not sufficient for resource attributes in practice because during validation we can't know yet whether a resource reference evaluates to a single object or to a list of objects (if count is set). To address this, here we reinstate some static validation of resource references by analyzing directly the reference objects, disregarding any instance index if present, and produce errors if the remaining subsequent traversal steps do not correspond to items within the resource type schema. This also allows us to produce some more specialized error messages for certain situations. In particular, we can recognize a reference like aws_instance.foo.count, which in 0.11 and prior was a weird special case for determining the count value of a resource block, and offer a helpful error showing the new length(aws_instance.foo) usage pattern. This eventually delegates to the static traversal validation logic that was added to the configschema package in a previous commit, which also includes some specialized error messages that distinguish between attributes and block types in the schema so that the errors relate more directly to constructs the user can see in the configuration. In future we could potentially move more of the checks from the dynamic schema construction step to the static validation step, but resources are the reference type that most needs this immediately due to the ambiguity caused by the instance indexing syntax. We can safely refactor other reference types to be statically validated in later releases. This is verified by two pre-existing context validate tests which we temporarily disabled during earlier work (now re-enabled) and also by a new validate test aimed specifically at the special case for the "count" attribute.	8 years ago
Martin Atkins	c937c06a03	terraform: ugly huge change to weave in new HCL2-oriented types ... Due to how deeply the configuration types go into Terraform Core, there isn't a great way to switch out to HCL2 gradually. As a consequence, this huge commit gets us from the old state to a _compilable_ new state, but does not yet attempt to fix any tests and has a number of known missing parts and bugs. We will continue to iterate on this in forthcoming commits, heading back towards passing tests and making Terraform fully-functional again. The three main goals here are: - Use the configuration models from the "configs" package instead of the older models in the "config" package, which is now deprecated and preserved only to help us write our migration tool. - Do expression inspection and evaluation using the functionality of the new "lang" package, instead of the Interpolator type and related functionality in the main "terraform" package. - Represent addresses of various objects using types in the addrs package, rather than hand-constructed strings. This is not critical to support the above, but was a big help during the implementation of these other points since it made it much more explicit what kind of address is expected in each context. Since our new packages are built to accommodate some future planned features that are not yet implemented (e.g. the "for_each" argument on resources, "count"/"for_each" on modules), and since there's still a fair amount of functionality still using old-style APIs, there is a moderate amount of shimming here to connect new assumptions with old, hopefully in a way that makes it easier to find and eliminate these shims later. I apologize in advance to the person who inevitably just found this huge commit while spelunking through the commit history.	8 years ago
Martin Atkins	a16ca2ec53	lang: new package for the runtime parts of the config language ... Whereas package "configs" deals with the static structure of the configuration language, this new package "lang" deals with the dynamic aspects such as expression evaluation. So far this mainly consists of populating a hcl.EvalContext that contains the values necessary to evaluate a block or an expression. There is also special handling here for dynamic block generation using the HCL "dynblock" extension, which is exposed in the public interface (rather than hiding it as an implementation detail of EvalBlock) so that the caller can then extract proper source locations for any result values using the expanded body. This also includes the beginnings of a replacement for the function table handling that currently lives in the old "config" package, but most of the functions are not yet ported and so this will expand in subsequent commits.	8 years ago