16 Commits (33dfeecbeefc745b93ceea8d9a614a9e754de6b8)

Author	SHA1	Message	Date
Martin Atkins	3f569b55c5	stacks: Some code consistency cleanups in preparation for first merge	2 years ago
Martin Atkins	91b8ea3d76	stackstate: A helper for loading state during tests ... The main entry point here assumes the caller is providing serialized state objects wrapped in anypb.Any messages. That's an inconvenient representation for hand-writing in tests, so the new function LoadFromDirectProto allows skipping the deserialization steps and instead has the caller write the wanted values as if they had already been parsed/unmarshaled.	2 years ago
Martin Atkins	9c698a1de6	stackstate: Remove stale comment in AppliedChangeResourceInstanceObject ... This comment was noting that an earlier stub of this function was only returning an external facing "state description" object and not including the raw state for use when creating future plans. That was subsequently fixed -- this now returns both description and raw forms -- but the comment stuck around.	2 years ago
Martin Atkins	6e7eff9b4b	stackruntime: Report deletion of resource instance objects ... Previously our strategy for reporting the "applied change" results for resource instance objects was to iterate over the final state and emit an object for each resource instance we found in there. That's not a sufficient solution though, because if any objects are deleted as part of applying the plan then they won't be in the final state and so we won't know to tell the caller that they should drop the relevant objects from the stack-level state. Instead, we'll keep track of all of the resource instance objects that could potentially be affected by applying a plan and then use that set to decide which "applied change" objects to emit. If one of the affected objects is not present in the final state then we'll assume it was deleted and so command the caller to delete its records of that object from both the raw state and the state description. With this in place, it's now possible to create a destroy-mode plan and then apply it to end up with no resource instances at all. The stack runtime itself is still missing handling of destroying its own objects like components and embedded stacks, so this isn't a complete solution but it does at least allow properly cleaning up the records of objects that exist in remote systems, so it's now easier to clean up a development environment with real infrastructure backing it.	2 years ago
Martin Atkins	8fd29e9439	stacks: Preserve prior state from plan to apply ... We need to retain the prior state (in a form that Terraform Core's modules runtime can accept) between the plan and apply phases because Terraform uses it to verify that the provider's "final plan" is consistent with the initial plan. We previously tried to do this by reusing the "old" value from the planned change, but that's not really possible in practice because of the historical implementation detail that Terraform wants state information in a JSON format and plan information in MessagePack. This also contains the beginnings of handling the "discarding" of unrecognized keys from the state data structures, although we'll probably need to do more in that area later since this is just the bare minimum.	2 years ago
Martin Atkins	5372d5eb98	stacks+rpcapi(stacks): Model deposed objects for resource instances ... Previously we incorrectly assumed that resource instances only have one "current" object each. However, resource instances can also have deposed objects which we must also keep track of. This is a breaking change to the rpcapi since we're now using a new message type for a resource instance _object_ address in several places. That breakage is intentional here because at the time of writing this commit the rpcapi is not yet in any stable release and we want to force updating our existing internal client to properly handle deposed objects too.	2 years ago
Martin Atkins	49511fe9a8	stackstate: Fuller round-tripping of resource instance object state ... This gets us ever closer to being able to preserve resource instance objects from one run to the next. In subsequent commits we'll make use of the "LoadFromProto" option to load the prior state during the planning phase and take it into account when we're deciding what actions to propose.	2 years ago
Martin Atkins	89776cd2a6	stackstate: Initial work on decoding and the state model ... This is a sketch of the overall structure of the prior state decoder and the model type it populates. Before we can complete this we'll need to slightly rework how the apply phase emits the raw events that this is consuming, and in particular to change the raw state representation to be JSON-based to match with how Terraform Core expects to receive it once reloaded. That will follow in later commits.	2 years ago
Martin Atkins	54622c68a5	stackstate: Generate "raw state" objects for resource instance objects ... Previously we just had a stub that only generated basic external description objects. Now we'll also emit "raw state" objects for these, and have some initial support for deposed objects too.	2 years ago
Martin Atkins	60431e738e	stackstate: Use the statekeys package for resource instance object keys ... We can now replace our previous interim "tmpKey" with a real key in the syntax decided by our separate statekeys package.	2 years ago
Martin Atkins	8b431f5038	stackstate/statekeys: Representation of stacks state keys ... Our model for state for a stack involves a set of objects that is each identified by an opaque string key. Although those keys are opaque to callers of Terraform Core, we will actually be using them for some meaning in Terraform Core itself, since that will avoid redundantly storing the same information both in the key and in the object associated with the key. This therefore aims to encapsulate the generation and parsing of these keys to help ensure we'll always use them consistently.	2 years ago
Martin Atkins	1cb96ebb32	stackstate: Add HashiCorp copyright comments	2 years ago
Martin Atkins	d91e5dc9f1	stackstate: Include correct object data when announcing applied resource ... Previously we just had this just stubbed out to always return an empty object because we didn't have the schema information available to transcode the JSON-encoded state data into the form our RPC API wants to produce. An earlier commit added the schema information we need, so we can now transcode just in time to produce the protocol buffers serialization of the applied change description. This is still otherwise just a stub implementation. We'll still need to deal with emitting the "raw" representation of this state for use in future plans, and make sure we're properly handling deposed objects, in future commits.	2 years ago
Martin Atkins	74215a4451	stacks: Include resource type schema in PlannedChange and AppliedChange ... Unfortunately for historical reasons the "terraform" package produces state and plan artifacts that have dynamic data elements pre-encoded in the formats that Terraform CLI's traditional plan and state formats use. Since Stacks uses different plan and state models, and exclusively uses MessagePack encoding for dynamic values in both, we'll sometimes need to transcode from one format to another when generating and decoding the stacks-oriented representations. Transcoding between these serialization formats requires access to the relevant schema because the formats themselves each have an infoset that is only a subset of Terraform's type system. Therefore we'll now annotate the PlannedChange and AppliedChange objects that include provider-specific data types with the schema required to transcode them. This commit does not yet actually arrange to make use of those schemas. That will follow in later commits.	2 years ago
Martin Atkins	48518b8233	stacks: A very basic stub of applied resource instance change announcements ... We'd like to start developing some clients for this part of the RPC API concurrently with remaining work here in Terraform Core, and so this is a bare-minimum implementation of emitting "applied change" events for resource instances just so there's something for client developers to test against. There are various things wrong with this, including but not limited to: - It always reports that the new state for a resource instance is an empty object, rather than including the correct updated object. - It only supports "current" resource instance objects, and ignores deposed ones. - It just uses the resource instance address alone as the key for the state description map, which is fine for now when we only have one kind of description object anyway but will not be sufficient for a real implementation that needs to emit various different kinds of object. We'll need to rework most of this in future commits, but this is hopefully sufficient to start implementing and testing API clients, at least to some extend, despite the crudity of the results.	2 years ago
Martin Atkins	fafa36e73a	stackeval: ApplyPlan function and initial supporting internals ... This is a first pass at actually driving the apply phase through to completion, using the ChangeExec function to schedule the real change operations from the plan and then, just like for planning, a visit to each participating object to ask it to check itself and report the results of any changes it has made. Many of our objects don't have any external side-effects of their own and so just need to check their results are still valid after the apply phase has replaced unknown values with known values. For those we can mostly just share the same logic between plan and apply aside from asking for ApplyPhase instead of PlanPhase. ComponentInstance and OutputValue are the two objects whose treatment differs the most between plan and apply, because both of those need to emit externally-visible "applied change" objects to explain their side-effects to the caller. The apply-walk driver has a lot of behavior in common with the existing plan-walk driver. For this commit we're just accepting that and having two very similar pieces of code that differ only in some leaf details. In a future commit we might try to generalize that so we can share more logic between the two, but only if we can do that without making the code significantly harder to read.	2 years ago