4 Commits (e8ee3f14a4ffcc5df888b2ec2b4e3bec1162dce7)

Author	SHA1	Message	Date
Martin Atkins	88e76fa9ef	configs/configschema: Introduce the NestingGroup mode for blocks ... In study of existing providers we've found a pattern we werent previously accounting for of using a nested block type to represent a group of arguments that relate to a particular feature that is always enabled but where it improves configuration readability to group all of its settings together in a nested block. The existing NestingSingle was not a good fit for this because it is designed under the assumption that the presence or absence of the block has some significance in enabling or disabling the relevant feature, and so for these always-active cases we'd generate a misleading plan where the settings for the feature appear totally absent, rather than showing the default values that will be selected. NestingGroup is, therefore, a slight variation of NestingSingle where presence vs. absence of the block is not distinguishable (it's never null) and instead its contents are treated as unset when the block is absent. This then in turn causes any default values associated with the nested arguments to be honored and displayed in the plan whenever the block is not explicitly configured. The current SDK cannot activate this mode, but that's okay because its "legacy type system" opt-out flag allows it to force a block to be processed in this way anyway. We're adding this now so that we can introduce the feature in a future SDK without causing a breaking change to the protocol, since the set of possible block nesting modes is not extensible.	7 years ago
Martin Atkins	31299e688d	core: Allow legacy SDK to opt out of plan-time safety checks ... Due to the inprecision of our shimming from the legacy SDK type system to the new Terraform Core type system, the legacy SDK produces a number of inconsistencies that produce only minor quirky behavior or broken edge-cases. To retain compatibility with those existing weird behaviors, the legacy SDK opts out of our safety checks. The intent here is to allow existing providers to continue to do their previous unsafe behaviors for now, accepting that this will allow certain quirky bugs from previous releases to persist, and then gradually migrate away from the legacy SDK and remove this opt-out on a per-resource basis over time. As with the apply-time safety check opt-out, this is reserved only for the legacy SDK and must not be used in any new SDK implementations. We still include any inconsistencies as warnings in the logs as an aid to anyone debugging weird behavior, so that they can see situations where blame may be misplaced in the user-visible error messages.	7 years ago
Martin Atkins	1530fe52f7	core: Legacy SDK providers opt out of our new apply result check ... The shim layer for the legacy SDK type system is not precise enough to guarantee it will produce identical results between plan and apply. In particular, values that are null during plan will often become zero-valued during apply. To avoid breaking those existing providers while still allowing us to introduce this check in the future, we'll introduce a rather-hacky new flag that allows the legacy SDK to signal that it is the legacy SDK and thus disable the check. Once we start phasing out the legacy SDK in favor of one that natively understands our new type system, we can stop setting this flag and thus get the additional safety of this check without breaking any previously-released providers. No other SDK is permitted to set this flag, and we will remove it if we ever introduce protocol version 6 in future, assuming that any provider supporting that protocol will always produce consistent results.	7 years ago
Martin Atkins	4fe9632f09	plugin: Establish our current plugin protocol as version 5 ... The main significant change here is that the package name for the proto definition is "tfplugin5", which is important because this name is part of the wire protocol for references to types defined in our package. Along with that, we also move the generated package into "internal" to make it explicit that importing the generated Go package from elsewhere is not the right approach for externally-implemented SDKs, which should instead vendor the proto definition they are using and generate their own stubs to ensure that the wire protocol is the only hard dependency between Terraform Core and plugins. After this is merged, any provider binaries built against our helper/schema package will need to be rebuilt so that they use the new "tfplugin5" package name instead of "proto". In a future commit we will include more elaborate and organized documentation on how an external codebase might make use of our RPC interface definition to implement an SDK, but the primary concern here is to ensure we have the right wire package name before release.	8 years ago