make grpcErr work for either plugin type

Extract a better function name and make the errors generic for different
plugin types.

plugin/grpc_error.go

@@ -0,0 +1,74 @@
+package plugin
+
+import (
+	"fmt"
+	"path"
+	"runtime"
+
+	"github.com/hashicorp/terraform/tfdiags"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+// grpcErr extracts some known error types and formats them into better
+// representations for core. This must only be called from plugin methods.
+// Since we don't use RPC status errors for the plugin protocol, these do not
+// contain any useful details, and we can return some text that at least
+// indicates the plugin call and possible error condition.
+func grpcErr(err error) (diags tfdiags.Diagnostics) {
+	if err == nil {
+		return
+	}
+
+	// extract the method name from the caller.
+	pc, _, _, ok := runtime.Caller(1)
+	if !ok {
+		logger.Error("unknown grpc call", "error", err)
+		return diags.Append(err)
+	}
+
+	f := runtime.FuncForPC(pc)
+
+	// Function names will contain the full import path. Take the last
+	// segment, which will let users know which method was being called.
+	_, requestName := path.Split(f.Name())
+
+	// Here we can at least correlate the error in the logs to a particular binary.
+	logger.Error(requestName, "error", err)
+
+	// TODO: while this expands the error codes into somewhat better messages,
+	// this still does not easily link the error to an actual user-recognizable
+	// plugin. The grpc plugin does not know its configured name, and the
+	// errors are in a list of diagnostics, making it hard for the caller to
+	// annotate the returned errors.
+	switch status.Code(err) {
+	case codes.Unavailable:
+		// This case is when the plugin has stopped running for some reason,
+		// and is usually the result of a crash.
+		diags = diags.Append(tfdiags.Sourceless(
+			tfdiags.Error,
+			"Plugin did not respond",
+			fmt.Sprintf("The plugin encountered an error, and failed to respond to the %s call. "+
+				"The plugin logs may contain more details.", requestName),
+		))
+	case codes.Canceled:
+		diags = diags.Append(tfdiags.Sourceless(
+			tfdiags.Error,
+			"Request cancelled",
+			fmt.Sprintf("The %s request was cancelled.", requestName),
+		))
+	case codes.Unimplemented:
+		diags = diags.Append(tfdiags.Sourceless(
+			tfdiags.Error,
+			"Unsupported plugin method",
+			fmt.Sprintf("The %s method is not supported by this plugin.", requestName),
+		))
+	default:
+		diags = diags.Append(tfdiags.Sourceless(
+			tfdiags.Error,
+			"Plugin error",
+			fmt.Sprintf("The plugin returned an unexpected error from %s: %v", requestName, err),
+		))
+	}
+	return
+}

plugin/grpc_provider.go

@@ -3,9 +3,6 @@ package plugin
 import (
 	"context"
 	"errors"
-	"fmt"
-	"runtime"
-	"strings"
 	"sync"
 
 	"github.com/zclconf/go-cty/cty"
@@ -15,12 +12,9 @@ import (
 	proto "github.com/hashicorp/terraform/internal/tfplugin5"
 	"github.com/hashicorp/terraform/plugin/convert"
 	"github.com/hashicorp/terraform/providers"
-	"github.com/hashicorp/terraform/tfdiags"
 	ctyjson "github.com/zclconf/go-cty/cty/json"
 	"github.com/zclconf/go-cty/cty/msgpack"
 	"google.golang.org/grpc"
-	"google.golang.org/grpc/codes"
-	"google.golang.org/grpc/status"
 )
 
 var logger = logging.HCLogger()
@@ -625,66 +619,3 @@ func decodeDynamicValue(v *proto.DynamicValue, ty cty.Type) (cty.Value, error) {
 	}
 	return res, err
 }
-
-// grpcErr extracts some known error types and formats them into better
-// representations for core. This must only be called from plugin methods.
-// Since we don't use RPC status errors for the plugin protocol, these do not
-// contain any useful details, and we can return some text that at least
-// indicates the plugin call and possible error condition.
-func grpcErr(err error) (diags tfdiags.Diagnostics) {
-	if err == nil {
-		return
-	}
-
-	// extract the method name from the caller.
-	pc, _, _, ok := runtime.Caller(1)
-	if !ok {
-		return diags.Append(err)
-	}
-
-	f := runtime.FuncForPC(pc)
-	requestName := f.Name()
-	dot := strings.LastIndex(requestName, ".")
-	if dot > 0 {
-		requestName = requestName[dot+1:]
-	}
-
-	// Here we can at least correlate the error in the logs to a particular binary.
-	logger.Error("GRPCProvider."+requestName, "error", err)
-
-	// TODO: while this expands the error codes into somewhat better messages,
-	// this still does not easily link the error to the an actual
-	// user-recognizable provider. The GRPCProvider does not know its
-	// configured name, and the errors are in a list of diagnostics, making it
-	// hard for the the caller to annotate the returned errors.
-	switch status.Code(err) {
-	case codes.Unavailable:
-		// This case is when the provider has stopped running for some reason,
-		// and is usually the result of a crash.
-		diags = diags.Append(tfdiags.Sourceless(
-			tfdiags.Error,
-			"Provider did not respond",
-			fmt.Sprintf("The provider encountered an error, and failed to respond to the %s call. "+
-				"The provider logs may contain more details", requestName),
-		))
-	case codes.Canceled:
-		diags = diags.Append(tfdiags.Sourceless(
-			tfdiags.Error,
-			"Request cancelled",
-			fmt.Sprintf("The %s request was cancelled.", requestName),
-		))
-	case codes.Unimplemented:
-		diags = diags.Append(tfdiags.Sourceless(
-			tfdiags.Error,
-			"Unsupported plugin method",
-			fmt.Sprintf("The %s method is not supported by this provider", requestName),
-		))
-	default:
-		diags = diags.Append(tfdiags.Sourceless(
-			tfdiags.Error,
-			"Provider error",
-			fmt.Sprintf("The provider returned an unexpected error from %s: %v", requestName, err),
-		))
-	}
-	return
-}

plugin/grpc_provisioner.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"errors"
 	"io"
-	"log"
 	"sync"
 
 	plugin "github.com/hashicorp/go-plugin"
@@ -61,7 +60,7 @@ func (p *GRPCProvisioner) GetSchema() (resp provisioners.GetSchemaResponse) {
 
 	protoResp, err := p.client.GetSchema(p.ctx, new(proto.GetProvisionerSchema_Request))
 	if err != nil {
-		resp.Diagnostics = resp.Diagnostics.Append(err)
+		resp.Diagnostics = resp.Diagnostics.Append(grpcErr(err))
 		return resp
 	}
 	resp.Diagnostics = resp.Diagnostics.Append(convert.ProtoToDiagnostics(protoResp.Diagnostics))
@@ -96,7 +95,7 @@ func (p *GRPCProvisioner) ValidateProvisionerConfig(r provisioners.ValidateProvi
 	}
 	protoResp, err := p.client.ValidateProvisionerConfig(p.ctx, protoReq)
 	if err != nil {
-		resp.Diagnostics = resp.Diagnostics.Append(err)
+		resp.Diagnostics = resp.Diagnostics.Append(grpcErr(err))
 		return resp
 	}
 	resp.Diagnostics = resp.Diagnostics.Append(convert.ProtoToDiagnostics(protoResp.Diagnostics))
@@ -130,7 +129,7 @@ func (p *GRPCProvisioner) ProvisionResource(r provisioners.ProvisionResourceRequ
 
 	outputClient, err := p.client.ProvisionResource(p.ctx, protoReq)
 	if err != nil {
-		resp.Diagnostics = resp.Diagnostics.Append(err)
+		resp.Diagnostics = resp.Diagnostics.Append(grpcErr(err))
 		return resp
 	}
 
@@ -169,7 +168,7 @@ func (p *GRPCProvisioner) Stop() error {
 func (p *GRPCProvisioner) Close() error {
 	// check this since it's not automatically inserted during plugin creation
 	if p.PluginClient == nil {
-		log.Println("[DEBUG] provider has no plugin.Client")
+		logger.Debug("provisioner has no plugin.Client")
 		return nil
 	}