fwserver: add list resources to GetMetadata

Author: bbasata

internal/fwserver/server.go

@@ -14,6 +14,7 @@ import (
 	"github.com/hashicorp/terraform-plugin-framework/function"
 	"github.com/hashicorp/terraform-plugin-framework/internal/fwschema"
 	"github.com/hashicorp/terraform-plugin-framework/internal/logging"
+	"github.com/hashicorp/terraform-plugin-framework/list"
 	"github.com/hashicorp/terraform-plugin-framework/provider"
 	"github.com/hashicorp/terraform-plugin-framework/resource"
 )
@@ -172,6 +173,20 @@ type Server struct {
 	// Provider.Resources() method.
 	resourceFuncs map[string]func() resource.Resource
 
+	// listResourceFuncs is the cached Resource List functions for RPCs that need to
+	// access resource lists. If not found, it will be fetched from the
+	// Provider.ListResources() method.
+	listResourceFuncs map[string]func() list.ListResource
+
+	// listResourceTypesDiags is the cached Diagnostics obtained while populating
+	// listResourceTypes. This is to ensure any warnings or errors are also
+	// returned appropriately when fetching listResourceTypes.
+	listResourceTypesDiags diag.Diagnostics
+
+	// listResourceTypesMutex is a mutex to protect concurrent listResourceTypes
+	// access from race conditions.
+	listResourceTypesMutex sync.Mutex
+
 	// resourceTypesDiags is the cached Diagnostics obtained while populating
 	// resourceTypes. This is to ensure any warnings or errors are also
 	// returned appropriately when fetching resourceTypes.
@@ -804,3 +819,88 @@ func (s *Server) ResourceIdentitySchemas(ctx context.Context) (map[string]fwsche
 
 	return resourceIdentitySchemas, diags
 }
+
+// ListResourceFuncs returns a map of ListResource functions. The results are
+// cached on first use.
+func (s *Server) ListResourceFuncs(ctx context.Context) (map[string]func() list.ListResource, diag.Diagnostics) {
+	provider, ok := s.Provider.(provider.ProviderWithListResources)
+	if !ok {
+		return nil, nil
+	}
+
+	logging.FrameworkTrace(ctx, "Checking ListResourceTypes lock")
+	s.listResourceTypesMutex.Lock()
+	defer s.listResourceTypesMutex.Unlock()
+
+	if s.listResourceFuncs != nil {
+		return s.listResourceFuncs, s.resourceTypesDiags
+	}
+
+	providerTypeName := s.ProviderTypeName(ctx)
+	s.listResourceFuncs = make(map[string]func() list.ListResource)
+
+	logging.FrameworkTrace(ctx, "Calling provider defined ListResources")
+	listResourceFuncSlice := provider.ListResources(ctx)
+	logging.FrameworkTrace(ctx, "Called provider defined ListResources")
+
+	for _, listResourceFunc := range listResourceFuncSlice {
+		listResource := listResourceFunc()
+
+		metadataReq := resource.MetadataRequest{
+			ProviderTypeName: providerTypeName,
+		}
+		metadataResp := resource.MetadataResponse{}
+		listResource.Metadata(ctx, metadataReq, &metadataResp)
+
+		typeName := metadataResp.TypeName
+		if typeName == "" {
+			s.listResourceTypesDiags.AddError(
+				"ListResource Type Name Missing",
+				fmt.Sprintf("The %T ListResource returned an empty string from the Metadata method. ", listResource)+
+					"This is always an issue with the provider and should be reported to the provider developers.",
+			)
+			continue
+		}
+
+		logging.FrameworkTrace(ctx, "Found resource type", map[string]interface{}{logging.KeyListResourceType: typeName}) // TODO: y?
+
+		if _, ok := s.listResourceFuncs[typeName]; ok {
+			s.listResourceTypesDiags.AddError(
+				"Duplicate ListResource Type Defined",
+				fmt.Sprintf("The %s ListResource type name was returned for multiple list resources. ", typeName)+
+					"ListResource type names must be unique. "+
+					"This is always an issue with the provider and should be reported to the provider developers.",
+			)
+			continue
+		}
+
+		if _, ok := s.resourceFuncs[typeName]; !ok {
+			s.listResourceTypesDiags.AddError(
+				"ListResource Type Defined without a Matching Managed Resource Type",
+				fmt.Sprintf("The %s ListResource type name was returned, but no matching managed Resource type was defined. ", typeName)+
+					"This is always an issue with the provider and should be reported to the provider developers.",
+			)
+			continue
+		}
+
+		s.listResourceFuncs[typeName] = listResourceFunc
+	}
+
+	return s.listResourceFuncs, s.listResourceTypesDiags
+}
+
+// ListResourceMetadatas returns a slice of ListResourceMetadata for the GetMetadata
+// RPC.
+func (s *Server) ListResourceMetadatas(ctx context.Context) ([]ListResourceMetadata, diag.Diagnostics) {
+	resourceFuncs, diags := s.ListResourceFuncs(ctx)
+
+	resourceMetadatas := make([]ListResourceMetadata, 0, len(resourceFuncs))
+
+	for typeName := range resourceFuncs {
+		resourceMetadatas = append(resourceMetadatas, ListResourceMetadata{
+			TypeName: typeName,
+		})
+	}
+
+	return resourceMetadatas, diags
+}

internal/fwserver/server_getmetadata.go

@@ -20,6 +20,7 @@ type GetMetadataResponse struct {
 	Diagnostics        diag.Diagnostics
 	EphemeralResources []EphemeralResourceMetadata
 	Functions          []FunctionMetadata
+	ListResources      []ListResourceMetadata
 	Resources          []ResourceMetadata
 	ServerCapabilities *ServerCapabilities
 }
@@ -52,28 +53,39 @@ type ResourceMetadata struct {
 	TypeName string
 }
 
+// ListResourceMetadata is the framework server equivalent of the
+// tfprotov5.ListResourceMetadata and tfprotov6.ListResourceMetadata types.
+type ListResourceMetadata struct {
+	// TypeName is the name of the list resource.
+	TypeName string
+}
+
 // GetMetadata implements the framework server GetMetadata RPC.
 func (s *Server) GetMetadata(ctx context.Context, req *GetMetadataRequest, resp *GetMetadataResponse) {
 	resp.DataSources = []DataSourceMetadata{}
 	resp.EphemeralResources = []EphemeralResourceMetadata{}
 	resp.Functions = []FunctionMetadata{}
+	resp.ListResources = []ListResourceMetadata{}
 	resp.Resources = []ResourceMetadata{}
+
 	resp.ServerCapabilities = s.ServerCapabilities()
 
 	datasourceMetadatas, diags := s.DataSourceMetadatas(ctx)
-
 	resp.Diagnostics.Append(diags...)
 
 	ephemeralResourceMetadatas, diags := s.EphemeralResourceMetadatas(ctx)
-
 	resp.Diagnostics.Append(diags...)
 
 	functionMetadatas, diags := s.FunctionMetadatas(ctx)
-
 	resp.Diagnostics.Append(diags...)
 
 	resourceMetadatas, diags := s.ResourceMetadatas(ctx)
+	resp.Diagnostics.Append(diags...)
 
+	// Metadata for list resources must be retrieved after metadata for managed
+	// resources. Server.ListResourceMetadatas checks that each list resource
+	// type nane matches a known managed Resource type name.
+	listResourceMetadatas, diags := s.ListResourceMetadatas(ctx)
 	resp.Diagnostics.Append(diags...)
 
 	if resp.Diagnostics.HasError() {
@@ -83,5 +95,6 @@ func (s *Server) GetMetadata(ctx context.Context, req *GetMetadataRequest, resp
 	resp.DataSources = datasourceMetadatas
 	resp.EphemeralResources = ephemeralResourceMetadatas
 	resp.Functions = functionMetadatas
+	resp.ListResources = listResourceMetadatas
 	resp.Resources = resourceMetadatas
 }