terraform/docs/plugin-protocol/tfplugin6.4.proto
Brian Flad 7094517089
Add GetMetadata RPC to provider protocol (#33739)
Reference: https://github.com/hashicorp/terraform/pull/33486

This is a followup to the new provider server capability to make the `GetProviderSchema` RPC optional. While this server capability would perform its intended function when directly talking to a single provider server SDK implementation, provider servers using terraform-plugin-mux need a methodology for the mux server to determine the available resource types of each underlying provider server to properly route resource-specific RPCs. Since the only methodology available to the mux server would be calling the `GetProviderSchema` RPC to each of underlying provider servers, any memory optimization of core caching would be lost.

The choice of adding a new RPC instead of adjusting the existing `GetProviderSchema` RPC with additional request information, such as "only list the type names and not the schema information in the response", is two-fold:

- Prevents the introduction of conditional logic for the existing RPC.
- Clearly delineates the purpose of the RPC and can be documented easier.

The choice of adding this to the existing provider service is two-fold:

- Implementing a separate protocol and/or service only on the provider side of the protocol would be a novel design change. This small of a change does not warrant the potential research and testing effort that would be associated with that implementation.
- While the core implementation will not use the new RPC immediately, there is no reason why it should be restricted from doing so in the future if a valid use case surfaces. Other ecosystem tools, beyond terraform-plugin-mux, can also potentially benefit from the lightweight RPC now.

This is changing the 5.4 and 6.4 protocol versions following the guidance of this comment in the definition files, since it directly relates to the prior intention of the new minor versions:

```protobuf
// Note that only the proto files included in a release tag of Terraform are
// official protocol releases. Proto files taken from other commits may include
// incomplete changes or features that did not make it into a final release.
// In all reasonable cases, plugin developers should take the proto file from
// the tag of the most recent release of Terraform, and not from the main
// branch or any other development branch.
```

As with any Protocol Buffers definition update, protocol compatibility is guaranteed within a major version, however generated protocol source code compatibility is not guaranteed. In this case, implementing the new RPC method in protocol wrapper types and the moving of the `ServerCapabilities` message to the top namespace are considered acceptable changes.
2023-08-24 14:35:42 -04:00

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Protocol Buffer

// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: MPL-2.0
// Terraform Plugin RPC protocol version 6.4
//
// This file defines version 6.4 of the RPC protocol. To implement a plugin
// against this protocol, copy this definition into your own codebase and
// use protoc to generate stubs for your target language.
//
// This file will not be updated. Any minor versions of protocol 6 to follow
// should copy this file and modify the copy while maintaing backwards
// compatibility. Breaking changes, if any are required, will come
// in a subsequent major version with its own separate proto definition.
//
// Note that only the proto files included in a release tag of Terraform are
// official protocol releases. Proto files taken from other commits may include
// incomplete changes or features that did not make it into a final release.
// In all reasonable cases, plugin developers should take the proto file from
// the tag of the most recent release of Terraform, and not from the main
// branch or any other development branch.
//
syntax = "proto3";
option go_package = "github.com/hashicorp/terraform/internal/tfplugin6";
package tfplugin6;
// DynamicValue is an opaque encoding of terraform data, with the field name
// indicating the encoding scheme used.
message DynamicValue {
bytes msgpack = 1;
bytes json = 2;
}
message Diagnostic {
enum Severity {
INVALID = 0;
ERROR = 1;
WARNING = 2;
}
Severity severity = 1;
string summary = 2;
string detail = 3;
AttributePath attribute = 4;
}
message AttributePath {
message Step {
oneof selector {
// Set "attribute_name" to represent looking up an attribute
// in the current object value.
string attribute_name = 1;
// Set "element_key_*" to represent looking up an element in
// an indexable collection type.
string element_key_string = 2;
int64 element_key_int = 3;
}
}
repeated Step steps = 1;
}
message StopProvider {
message Request {
}
message Response {
string Error = 1;
}
}
// RawState holds the stored state for a resource to be upgraded by the
// provider. It can be in one of two formats, the current json encoded format
// in bytes, or the legacy flatmap format as a map of strings.
message RawState {
bytes json = 1;
map<string, string> flatmap = 2;
}
enum StringKind {
PLAIN = 0;
MARKDOWN = 1;
}
// Schema is the configuration schema for a Resource or Provider.
message Schema {
message Block {
int64 version = 1;
repeated Attribute attributes = 2;
repeated NestedBlock block_types = 3;
string description = 4;
StringKind description_kind = 5;
bool deprecated = 6;
}
message Attribute {
string name = 1;
bytes type = 2;
Object nested_type = 10;
string description = 3;
bool required = 4;
bool optional = 5;
bool computed = 6;
bool sensitive = 7;
StringKind description_kind = 8;
bool deprecated = 9;
}
message NestedBlock {
enum NestingMode {
INVALID = 0;
SINGLE = 1;
LIST = 2;
SET = 3;
MAP = 4;
GROUP = 5;
}
string type_name = 1;
Block block = 2;
NestingMode nesting = 3;
int64 min_items = 4;
int64 max_items = 5;
}
message Object {
enum NestingMode {
INVALID = 0;
SINGLE = 1;
LIST = 2;
SET = 3;
MAP = 4;
}
repeated Attribute attributes = 1;
NestingMode nesting = 3;
// MinItems and MaxItems were never used in the protocol, and have no
// effect on validation.
int64 min_items = 4 [deprecated = true];
int64 max_items = 5 [deprecated = true];
}
// The version of the schema.
// Schemas are versioned, so that providers can upgrade a saved resource
// state when the schema is changed.
int64 version = 1;
// Block is the top level configuration block for this schema.
Block block = 2;
}
// ServerCapabilities allows providers to communicate extra information
// regarding supported protocol features. This is used to indicate
// availability of certain forward-compatible changes which may be optional
// in a major protocol version, but cannot be tested for directly.
message ServerCapabilities {
// The plan_destroy capability signals that a provider expects a call
// to PlanResourceChange when a resource is going to be destroyed.
bool plan_destroy = 1;
// The get_provider_schema_optional capability indicates that this
// provider does not require calling GetProviderSchema to operate
// normally, and the caller can used a cached copy of the provider's
// schema.
bool get_provider_schema_optional = 2;
}
service Provider {
//////// Information about what a provider supports/expects
// GetMetadata returns upfront information about server capabilities and
// supported resource types without requiring the server to instantiate all
// schema information, which may be memory intensive. This RPC is optional,
// where clients may receive an unimplemented RPC error. Clients should
// ignore the error and call the GetProviderSchema RPC as a fallback.
rpc GetMetadata(GetMetadata.Request) returns (GetMetadata.Response);
// GetSchema returns schema information for the provider, data resources,
// and managed resources.
rpc GetProviderSchema(GetProviderSchema.Request) returns (GetProviderSchema.Response);
rpc ValidateProviderConfig(ValidateProviderConfig.Request) returns (ValidateProviderConfig.Response);
rpc ValidateResourceConfig(ValidateResourceConfig.Request) returns (ValidateResourceConfig.Response);
rpc ValidateDataResourceConfig(ValidateDataResourceConfig.Request) returns (ValidateDataResourceConfig.Response);
rpc UpgradeResourceState(UpgradeResourceState.Request) returns (UpgradeResourceState.Response);
//////// One-time initialization, called before other functions below
rpc ConfigureProvider(ConfigureProvider.Request) returns (ConfigureProvider.Response);
//////// Managed Resource Lifecycle
rpc ReadResource(ReadResource.Request) returns (ReadResource.Response);
rpc PlanResourceChange(PlanResourceChange.Request) returns (PlanResourceChange.Response);
rpc ApplyResourceChange(ApplyResourceChange.Request) returns (ApplyResourceChange.Response);
rpc ImportResourceState(ImportResourceState.Request) returns (ImportResourceState.Response);
rpc ReadDataSource(ReadDataSource.Request) returns (ReadDataSource.Response);
//////// Graceful Shutdown
rpc StopProvider(StopProvider.Request) returns (StopProvider.Response);
}
message GetMetadata {
message Request {
}
message Response {
ServerCapabilities server_capabilities = 1;
repeated Diagnostic diagnostics = 2;
repeated DataSourceMetadata data_sources = 3;
repeated ResourceMetadata resources = 4;
}
message DataSourceMetadata {
string type_name = 1;
}
message ResourceMetadata {
string type_name = 1;
}
}
message GetProviderSchema {
message Request {
}
message Response {
Schema provider = 1;
map<string, Schema> resource_schemas = 2;
map<string, Schema> data_source_schemas = 3;
repeated Diagnostic diagnostics = 4;
Schema provider_meta = 5;
ServerCapabilities server_capabilities = 6;
}
}
message ValidateProviderConfig {
message Request {
DynamicValue config = 1;
}
message Response {
repeated Diagnostic diagnostics = 2;
}
}
message UpgradeResourceState {
// Request is the message that is sent to the provider during the
// UpgradeResourceState RPC.
//
// This message intentionally does not include configuration data as any
// configuration-based or configuration-conditional changes should occur
// during the PlanResourceChange RPC. Additionally, the configuration is
// not guaranteed to exist (in the case of resource destruction), be wholly
// known, nor match the given prior state, which could lead to unexpected
// provider behaviors for practitioners.
message Request {
string type_name = 1;
// version is the schema_version number recorded in the state file
int64 version = 2;
// raw_state is the raw states as stored for the resource. Core does
// not have access to the schema of prior_version, so it's the
// provider's responsibility to interpret this value using the
// appropriate older schema. The raw_state will be the json encoded
// state, or a legacy flat-mapped format.
RawState raw_state = 3;
}
message Response {
// new_state is a msgpack-encoded data structure that, when interpreted with
// the _current_ schema for this resource type, is functionally equivalent to
// that which was given in prior_state_raw.
DynamicValue upgraded_state = 1;
// diagnostics describes any errors encountered during migration that could not
// be safely resolved, and warnings about any possibly-risky assumptions made
// in the upgrade process.
repeated Diagnostic diagnostics = 2;
}
}
message ValidateResourceConfig {
message Request {
string type_name = 1;
DynamicValue config = 2;
}
message Response {
repeated Diagnostic diagnostics = 1;
}
}
message ValidateDataResourceConfig {
message Request {
string type_name = 1;
DynamicValue config = 2;
}
message Response {
repeated Diagnostic diagnostics = 1;
}
}
message ConfigureProvider {
message Request {
string terraform_version = 1;
DynamicValue config = 2;
}
message Response {
repeated Diagnostic diagnostics = 1;
}
}
message ReadResource {
// Request is the message that is sent to the provider during the
// ReadResource RPC.
//
// This message intentionally does not include configuration data as any
// configuration-based or configuration-conditional changes should occur
// during the PlanResourceChange RPC. Additionally, the configuration is
// not guaranteed to be wholly known nor match the given prior state, which
// could lead to unexpected provider behaviors for practitioners.
message Request {
string type_name = 1;
DynamicValue current_state = 2;
bytes private = 3;
DynamicValue provider_meta = 4;
}
message Response {
DynamicValue new_state = 1;
repeated Diagnostic diagnostics = 2;
bytes private = 3;
}
}
message PlanResourceChange {
message Request {
string type_name = 1;
DynamicValue prior_state = 2;
DynamicValue proposed_new_state = 3;
DynamicValue config = 4;
bytes prior_private = 5;
DynamicValue provider_meta = 6;
}
message Response {
DynamicValue planned_state = 1;
repeated AttributePath requires_replace = 2;
bytes planned_private = 3;
repeated Diagnostic diagnostics = 4;
// This may be set only by the helper/schema "SDK" in the main Terraform
// repository, to request that Terraform Core >=0.12 permit additional
// inconsistencies that can result from the legacy SDK type system
// and its imprecise mapping to the >=0.12 type system.
// The change in behavior implied by this flag makes sense only for the
// specific details of the legacy SDK type system, and are not a general
// mechanism to avoid proper type handling in providers.
//
// ==== DO NOT USE THIS ====
// ==== THIS MUST BE LEFT UNSET IN ALL OTHER SDKS ====
// ==== DO NOT USE THIS ====
bool legacy_type_system = 5;
}
}
message ApplyResourceChange {
message Request {
string type_name = 1;
DynamicValue prior_state = 2;
DynamicValue planned_state = 3;
DynamicValue config = 4;
bytes planned_private = 5;
DynamicValue provider_meta = 6;
}
message Response {
DynamicValue new_state = 1;
bytes private = 2;
repeated Diagnostic diagnostics = 3;
// This may be set only by the helper/schema "SDK" in the main Terraform
// repository, to request that Terraform Core >=0.12 permit additional
// inconsistencies that can result from the legacy SDK type system
// and its imprecise mapping to the >=0.12 type system.
// The change in behavior implied by this flag makes sense only for the
// specific details of the legacy SDK type system, and are not a general
// mechanism to avoid proper type handling in providers.
//
// ==== DO NOT USE THIS ====
// ==== THIS MUST BE LEFT UNSET IN ALL OTHER SDKS ====
// ==== DO NOT USE THIS ====
bool legacy_type_system = 4;
}
}
message ImportResourceState {
message Request {
string type_name = 1;
string id = 2;
}
message ImportedResource {
string type_name = 1;
DynamicValue state = 2;
bytes private = 3;
}
message Response {
repeated ImportedResource imported_resources = 1;
repeated Diagnostic diagnostics = 2;
}
}
message ReadDataSource {
message Request {
string type_name = 1;
DynamicValue config = 2;
DynamicValue provider_meta = 3;
}
message Response {
DynamicValue state = 1;
repeated Diagnostic diagnostics = 2;
}
}