WIP generate resource config RPC

go.mod

@@ -6,9 +6,9 @@ toolchain go1.24.4
 
 require (
 	github.com/google/go-cmp v0.7.0
-	github.com/hashicorp/terraform-plugin-go v0.29.0
+	github.com/hashicorp/terraform-plugin-go v0.29.1-0.20251112131031-c841d34ce2f2
 	github.com/hashicorp/terraform-plugin-log v0.9.0
-	google.golang.org/grpc v1.75.1
+	google.golang.org/grpc v1.76.0
 )
 
 require (
@@ -29,6 +29,6 @@ require (
 	golang.org/x/net v0.43.0 // indirect
 	golang.org/x/sys v0.35.0 // indirect
 	golang.org/x/text v0.28.0 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20250707201910-8d1bb00bc6a7 // indirect
-	google.golang.org/protobuf v1.36.9 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20250804133106-a7a43d27e69b // indirect
+	google.golang.org/protobuf v1.36.10 // indirect
 )

go.sum

@@ -23,8 +23,8 @@ github.com/hashicorp/go-plugin v1.7.0 h1:YghfQH/0QmPNc/AZMTFE3ac8fipZyZECHdDPshf
 github.com/hashicorp/go-plugin v1.7.0/go.mod h1:BExt6KEaIYx804z8k4gRzRLEvxKVb+kn0NMcihqOqb8=
 github.com/hashicorp/go-uuid v1.0.3 h1:2gKiV6YVmrJ1i2CKKa9obLvRieoRGviZFL26PcT/Co8=
 github.com/hashicorp/go-uuid v1.0.3/go.mod h1:6SBZvOh/SIDV7/2o3Jml5SYk/TvGqwFJ/bN7x4byOro=
-github.com/hashicorp/terraform-plugin-go v0.29.0 h1:1nXKl/nSpaYIUBU1IG/EsDOX0vv+9JxAltQyDMpq5mU=
-github.com/hashicorp/terraform-plugin-go v0.29.0/go.mod h1:vYZbIyvxyy0FWSmDHChCqKvI40cFTDGSb3D8D70i9GM=
+github.com/hashicorp/terraform-plugin-go v0.29.1-0.20251112131031-c841d34ce2f2 h1:GxLILx5hl084NZFVBc6rdzKrJ5DL8MYNaQapmXFcOHY=
+github.com/hashicorp/terraform-plugin-go v0.29.1-0.20251112131031-c841d34ce2f2/go.mod h1:KHRnT9vExG+r1fLxwOzOP6C6YXiaKHtsCIrky7teDYc=
 github.com/hashicorp/terraform-plugin-log v0.9.0 h1:i7hOA+vdAItN1/7UrfBqBwvYPQ9TFvymaRGZED3FCV0=
 github.com/hashicorp/terraform-plugin-log v0.9.0/go.mod h1:rKL8egZQ/eXSyDqzLUuwUYLVdlYeamldAHSxjUFADow=
 github.com/hashicorp/terraform-registry-address v0.4.0 h1:S1yCGomj30Sao4l5BMPjTGZmCNzuv7/GDTDX99E9gTk=
@@ -86,12 +86,12 @@ golang.org/x/text v0.28.0 h1:rhazDwis8INMIwQ4tpjLDzUhx6RlXqZNPEM0huQojng=
 golang.org/x/text v0.28.0/go.mod h1:U8nCwOR8jO/marOQ0QbDiOngZVEBB7MAiitBuMjXiNU=
 gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
 gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20250707201910-8d1bb00bc6a7 h1:pFyd6EwwL2TqFf8emdthzeX+gZE1ElRq3iM8pui4KBY=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20250707201910-8d1bb00bc6a7/go.mod h1:qQ0YXyHHx3XkvlzUtpXDkS29lDSafHMZBAZDc03LQ3A=
-google.golang.org/grpc v1.75.1 h1:/ODCNEuf9VghjgO3rqLcfg8fiOP0nSluljWFlDxELLI=
-google.golang.org/grpc v1.75.1/go.mod h1:JtPAzKiq4v1xcAB2hydNlWI2RnF85XXcV0mhKXr2ecQ=
-google.golang.org/protobuf v1.36.9 h1:w2gp2mA27hUeUzj9Ex9FBjsBm40zfaDtEWow293U7Iw=
-google.golang.org/protobuf v1.36.9/go.mod h1:fuxRtAxBytpl4zzqUh6/eyUujkJdNiuEkXntxiD/uRU=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20250804133106-a7a43d27e69b h1:zPKJod4w6F1+nRGDI9ubnXYhU9NSWoFAijkHkUXeTK8=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20250804133106-a7a43d27e69b/go.mod h1:qQ0YXyHHx3XkvlzUtpXDkS29lDSafHMZBAZDc03LQ3A=
+google.golang.org/grpc v1.76.0 h1:UnVkv1+uMLYXoIz6o7chp59WfQUYA2ex/BXQ9rHZu7A=
+google.golang.org/grpc v1.76.0/go.mod h1:Ju12QI8M6iQJtbcsV+awF5a4hfJMLi4X0JLo94ULZ6c=
+google.golang.org/protobuf v1.36.10 h1:AYd7cD/uASjIL6Q9LiTjz8JLcrh/88q5UObnmY3aOOE=
+google.golang.org/protobuf v1.36.10/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

tf5muxserver/diagnostics.go

@@ -68,6 +68,16 @@ func ephemeralResourceMissingError(typeName string) *tfprotov5.Diagnostic {
 	}
 }
 
+func generateResourceConfigMissingError(typeName string) *tfprotov5.Diagnostic {
+	return &tfprotov5.Diagnostic{
+		Severity: tfprotov5.DiagnosticSeverityError,
+		Summary:  "Generate Resource Config Not Implemented",
+		Detail: "The combined provider does not implement the requested generate resource config for the resource type. " +
+			"This is always an issue in the provider implementation and should be reported to the provider developers.\n\n" +
+			"Missing generate resource config for resource type: " + typeName,
+	}
+}
+
 func listResourceDuplicateError(typeName string) *tfprotov5.Diagnostic {
 	return &tfprotov5.Diagnostic{
 		Severity: tfprotov5.DiagnosticSeverityError,

tf5muxserver/mux_server.go

@@ -7,10 +7,10 @@ import (
 	"context"
 	"sync"
 
-	"github.com/hashicorp/terraform-plugin-go/tfprotov5"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 
+	"github.com/hashicorp/terraform-plugin-go/tfprotov5"
 	"github.com/hashicorp/terraform-plugin-mux/internal/logging"
 )
 
@@ -65,6 +65,10 @@ func (s *muxServer) ProviderServer() tfprotov5.ProviderServer {
 	return s
 }
 
+func (s *muxServer) ProviderServers() []tfprotov5.ProviderServer {
+	return s.servers
+}
+
 func (s *muxServer) getActionServer(ctx context.Context, actionType string) (tfprotov5.ProviderServer, []*tfprotov5.Diagnostic, error) {
 	s.serverDiscoveryMutex.RLock()
 	server, ok := s.actions[actionType]
@@ -170,6 +174,41 @@ func (s *muxServer) getEphemeralResourceServer(ctx context.Context, typeName str
 	return server, s.serverDiscoveryDiagnostics, nil
 }
 
+func (s *muxServer) getGenerateResourceConfigServer(ctx context.Context, typeName string) (tfprotov5.ProviderServer, []*tfprotov5.Diagnostic, error) {
+	s.serverDiscoveryMutex.RLock()
+	server, ok := s.resources[typeName]
+	discoveryComplete := s.serverDiscoveryComplete
+	s.serverDiscoveryMutex.RUnlock()
+
+	if discoveryComplete {
+		if ok {
+			return server, s.serverDiscoveryDiagnostics, nil
+		}
+
+		return nil, []*tfprotov5.Diagnostic{
+			generateResourceConfigMissingError(typeName),
+		}, nil
+	}
+
+	err := s.serverDiscovery(ctx)
+
+	if err != nil || diagnosticsHasError(s.serverDiscoveryDiagnostics) {
+		return nil, s.serverDiscoveryDiagnostics, err
+	}
+
+	s.serverDiscoveryMutex.RLock()
+	server, ok = s.resources[typeName]
+	s.serverDiscoveryMutex.RUnlock()
+
+	if !ok {
+		return nil, []*tfprotov5.Diagnostic{
+			generateResourceConfigMissingError(typeName),
+		}, nil
+	}
+
+	return server, s.serverDiscoveryDiagnostics, nil
+}
+
 func (s *muxServer) getListResourceServer(ctx context.Context, typeName string) (tfprotov5.ProviderServer, []*tfprotov5.Diagnostic, error) {
 	s.serverDiscoveryMutex.RLock()
 	server, ok := s.listResources[typeName]

tf5muxserver/mux_server_GenerateResourceConfig.go

@@ -0,0 +1,52 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package tf5muxserver
+
+import (
+	"context"
+
+	"github.com/hashicorp/terraform-plugin-go/tfprotov5"
+	"github.com/hashicorp/terraform-plugin-mux/internal/logging"
+)
+
+func (s *muxServer) GenerateResourceConfig(ctx context.Context, req *tfprotov5.GenerateResourceConfigRequest) (*tfprotov5.GenerateResourceConfigResponse, error) {
+	rpc := "GenerateResourceConfig"
+	ctx = logging.InitContext(ctx)
+	ctx = logging.RpcContext(ctx, rpc)
+
+	server, diags, err := s.getGenerateResourceConfigServer(ctx, req.TypeName)
+
+	if err != nil {
+		return nil, err
+	}
+
+	// If there is an error diagnostic, return it directly
+	if diagnosticsHasError(diags) {
+		return &tfprotov5.GenerateResourceConfigResponse{
+			Diagnostics: diags,
+		}, nil
+	}
+
+	// TODO: Remove and call server.GenerateResourceConfig below directly once interface becomes required.
+	generateResourceConfigServer, ok := server.(tfprotov5.GenerateResourceConfigServer)
+	if !ok {
+		resp := &tfprotov5.GenerateResourceConfigResponse{
+			Diagnostics: []*tfprotov5.Diagnostic{
+				{
+					Severity: tfprotov5.DiagnosticSeverityError,
+					Summary:  "GenerateResourceConfig Not Implemented",
+					Detail: "A GenerateResourceConfig call was received by the provider, however the provider does not implement GenerateResourceConfig. " +
+						"Either upgrade the provider to a version that implements GenerateResourceConfig or this is a bug in Terraform that should be reported to the Terraform maintainers.",
+				},
+			},
+		}
+
+		return resp, nil
+	}
+
+	ctx = logging.Tfprotov5ProviderServerContext(ctx, server)
+	logging.MuxTrace(ctx, "calling downstream server")
+
+	return generateResourceConfigServer.GenerateResourceConfig(ctx, req)
+}

tf5muxserver/mux_server_GetMetadata_test.go

@@ -187,6 +187,7 @@ func TestMuxServerGetMetadata(t *testing.T) {
 				GetProviderSchemaOptional: true,
 				MoveResourceState:         true,
 				PlanDestroy:               true,
+				GenerateResourceConfig:    true,
 			},
 		},
 		"duplicate-action": {
@@ -234,6 +235,7 @@ func TestMuxServerGetMetadata(t *testing.T) {
 				GetProviderSchemaOptional: true,
 				MoveResourceState:         true,
 				PlanDestroy:               true,
+				GenerateResourceConfig:    true,
 			},
 		},
 		"duplicate-data-source-type": {
@@ -281,6 +283,7 @@ func TestMuxServerGetMetadata(t *testing.T) {
 				GetProviderSchemaOptional: true,
 				MoveResourceState:         true,
 				PlanDestroy:               true,
+				GenerateResourceConfig:    true,
 			},
 		},
 		"duplicate-ephemeral-resource-type": {
@@ -328,6 +331,7 @@ func TestMuxServerGetMetadata(t *testing.T) {
 				GetProviderSchemaOptional: true,
 				MoveResourceState:         true,
 				PlanDestroy:               true,
+				GenerateResourceConfig:    true,
 			},
 		},
 		"duplicate-list-resource-type": {
@@ -375,6 +379,7 @@ func TestMuxServerGetMetadata(t *testing.T) {
 				GetProviderSchemaOptional: true,
 				MoveResourceState:         true,
 				PlanDestroy:               true,
+				GenerateResourceConfig:    true,
 			},
 		},
 		"duplicate-function": {
@@ -422,6 +427,7 @@ func TestMuxServerGetMetadata(t *testing.T) {
 				GetProviderSchemaOptional: true,
 				MoveResourceState:         true,
 				PlanDestroy:               true,
+				GenerateResourceConfig:    true,
 			},
 		},
 		"duplicate-resource-type": {
@@ -469,6 +475,7 @@ func TestMuxServerGetMetadata(t *testing.T) {
 				GetProviderSchemaOptional: true,
 				MoveResourceState:         true,
 				PlanDestroy:               true,
+				GenerateResourceConfig:    true,
 			},
 		},
 		"server-capabilities": {
@@ -514,6 +521,7 @@ func TestMuxServerGetMetadata(t *testing.T) {
 				GetProviderSchemaOptional: true,
 				MoveResourceState:         true,
 				PlanDestroy:               true,
+				GenerateResourceConfig:    true,
 			},
 		},
 		"error-once": {
@@ -549,6 +557,7 @@ func TestMuxServerGetMetadata(t *testing.T) {
 				GetProviderSchemaOptional: true,
 				MoveResourceState:         true,
 				PlanDestroy:               true,
+				GenerateResourceConfig:    true,
 			},
 		},
 		"error-multiple": {
@@ -599,6 +608,7 @@ func TestMuxServerGetMetadata(t *testing.T) {
 				GetProviderSchemaOptional: true,
 				MoveResourceState:         true,
 				PlanDestroy:               true,
+				GenerateResourceConfig:    true,
 			},
 		},
 		"warning-once": {
@@ -634,6 +644,7 @@ func TestMuxServerGetMetadata(t *testing.T) {
 				GetProviderSchemaOptional: true,
 				MoveResourceState:         true,
 				PlanDestroy:               true,
+				GenerateResourceConfig:    true,
 			},
 		},
 		"warning-multiple": {
@@ -684,6 +695,7 @@ func TestMuxServerGetMetadata(t *testing.T) {
 				GetProviderSchemaOptional: true,
 				MoveResourceState:         true,
 				PlanDestroy:               true,
+				GenerateResourceConfig:    true,
 			},
 		},
 		"warning-then-error": {
@@ -734,6 +746,7 @@ func TestMuxServerGetMetadata(t *testing.T) {
 				GetProviderSchemaOptional: true,
 				MoveResourceState:         true,
 				PlanDestroy:               true,
+				GenerateResourceConfig:    true,
 			},
 		},
 	}