serve the new version 5 grpc plugins

Use the new go-plugin version negotiation to server th appropriate
plugin type when the client requests protocol version 5.

plugin/grpc_provider.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"sync"
 
+	plugin "github.com/hashicorp/go-plugin"
 	"github.com/hashicorp/terraform/plugin/proto"
 	"github.com/hashicorp/terraform/providers"
 	"github.com/hashicorp/terraform/version"
@@ -12,6 +13,25 @@ import (
 	"google.golang.org/grpc"
 )
 
+// GRPCProviderPlugin implements plugin.GRPCPlugin for the go-plugin package.
+type GRPCProviderPlugin struct {
+	plugin.Plugin
+	GRPCProvider func() proto.ProviderServer
+}
+
+func (p *GRPCProviderPlugin) GRPCClient(ctx context.Context, broker *plugin.GRPCBroker, c *grpc.ClientConn) (interface{}, error) {
+	return &GRPCProvider{
+		conn:   c,
+		client: proto.NewProviderClient(c),
+		ctx:    ctx,
+	}, nil
+}
+
+func (p *GRPCProviderPlugin) GRPCServer(broker *plugin.GRPCBroker, s *grpc.Server) error {
+	proto.RegisterProviderServer(s, p.GRPCProvider())
+	return nil
+}
+
 // GRPCProvider handles the client, or core side of the plugin rpc connection.
 // The GRPCProvider methods are mostly a translation layer between the
 // terraform provioders types and the grpc proto types, directly converting

plugin/grpc_provisioner.go

@@ -6,6 +6,7 @@ import (
 	"io"
 	"sync"
 
+	plugin "github.com/hashicorp/go-plugin"
 	"github.com/hashicorp/terraform/configs/configschema"
 	"github.com/hashicorp/terraform/plugin/proto"
 	"github.com/hashicorp/terraform/provisioners"
@@ -14,6 +15,25 @@ import (
 	"google.golang.org/grpc"
 )
 
+// GRPCProvisionerPlugin is the plugin.GRPCPlugin implementation.
+type GRPCProvisionerPlugin struct {
+	plugin.Plugin
+	GRPCProvisioner func() proto.ProvisionerServer
+}
+
+func (p *GRPCProvisionerPlugin) GRPCClient(ctx context.Context, broker *plugin.GRPCBroker, c *grpc.ClientConn) (interface{}, error) {
+	return &GRPCProvisioner{
+		conn:   c,
+		client: proto.NewProvisionerClient(c),
+		ctx:    ctx,
+	}, nil
+}
+
+func (p *GRPCProvisionerPlugin) GRPCServer(broker *plugin.GRPCBroker, s *grpc.Server) error {
+	proto.RegisterProvisionerServer(s, p.GRPCProvisioner())
+	return nil
+}
+
 // provisioners.Interface grpc implementation
 type GRPCProvisioner struct {
 	conn   *grpc.ClientConn

plugin/resource_provider.go

@@ -9,11 +9,14 @@ import (
 
 // ResourceProviderPlugin is the plugin.Plugin implementation.
 type ResourceProviderPlugin struct {
-	F func() terraform.ResourceProvider
+	ResourceProvider func() terraform.ResourceProvider
 }
 
 func (p *ResourceProviderPlugin) Server(b *plugin.MuxBroker) (interface{}, error) {
-	return &ResourceProviderServer{Broker: b, Provider: p.F()}, nil
+	return &ResourceProviderServer{
+		Broker:   b,
+		Provider: p.ResourceProvider(),
+	}, nil
 }
 
 func (p *ResourceProviderPlugin) Client(

plugin/resource_provisioner.go

@@ -10,11 +10,14 @@ import (
 
 // ResourceProvisionerPlugin is the plugin.Plugin implementation.
 type ResourceProvisionerPlugin struct {
-	F func() terraform.ResourceProvisioner
+	ResourceProvisioner func() terraform.ResourceProvisioner
 }
 
 func (p *ResourceProvisionerPlugin) Server(b *plugin.MuxBroker) (interface{}, error) {
-	return &ResourceProvisionerServer{Broker: b, Provisioner: p.F()}, nil
+	return &ResourceProvisionerServer{
+		Broker:      b,
+		Provisioner: p.ResourceProvisioner(),
+	}, nil
 }
 
 func (p *ResourceProvisionerPlugin) Client(

plugin/serve.go

@@ -2,6 +2,8 @@ package plugin
 
 import (
 	"github.com/hashicorp/go-plugin"
+	grpcplugin "github.com/hashicorp/terraform/helper/plugin"
+	"github.com/hashicorp/terraform/plugin/proto"
 	"github.com/hashicorp/terraform/terraform"
 )
 
@@ -28,27 +30,82 @@ var Handshake = plugin.HandshakeConfig{
 
 type ProviderFunc func() terraform.ResourceProvider
 type ProvisionerFunc func() terraform.ResourceProvisioner
+type GRPCProviderFunc func() proto.ProviderServer
+type GRPCProvisionerFunc func() proto.ProvisionerServer
 
 // ServeOpts are the configurations to serve a plugin.
 type ServeOpts struct {
 	ProviderFunc    ProviderFunc
 	ProvisionerFunc ProvisionerFunc
+
+	// Wrapped versions of the above plugins will automatically shimmed and
+	// added to the GRPC functions when possible.
+	GRPCProviderFunc    GRPCProviderFunc
+	GRPCProvisionerFunc GRPCProvisionerFunc
 }
 
 // Serve serves a plugin. This function never returns and should be the final
 // function called in the main function of the plugin.
 func Serve(opts *ServeOpts) {
+	// since the plugins may not yet be aware of the new protocol, we
+	// automatically wrap the plugins in the grpc shims.
+	if opts.GRPCProviderFunc == nil && opts.ProviderFunc != nil {
+		provider := grpcplugin.NewGRPCProviderServerShim(opts.ProviderFunc())
+		// this is almost always going to be a *schema.Provider, but check that
+		// we got back a valid provider just in case.
+		if provider != nil {
+			opts.GRPCProviderFunc = func() proto.ProviderServer {
+				return provider
+			}
+		}
+	}
+	if opts.GRPCProvisionerFunc == nil && opts.ProvisionerFunc != nil {
+		provider := grpcplugin.NewGRPCProvisionerServerShim(opts.ProvisionerFunc())
+		if provider != nil {
+			opts.GRPCProvisionerFunc = func() proto.ProvisionerServer {
+				return provider
+			}
+		}
+	}
+
 	plugin.Serve(&plugin.ServeConfig{
 		HandshakeConfig:  Handshake,
-		Plugins:         pluginMap(opts),
+		VersionedPlugins: pluginSet(opts),
+		GRPCServer:       plugin.DefaultGRPCServer,
 	})
 }
 
-// pluginMap returns the map[string]plugin.Plugin to use for configuring a plugin
-// server or client.
+// pluginMap returns the legacy map[string]plugin.Plugin to use for configuring
+// a plugin server or client.
 func pluginMap(opts *ServeOpts) map[string]plugin.Plugin {
 	return map[string]plugin.Plugin{
-		"provider":    &ResourceProviderPlugin{F: opts.ProviderFunc},
-		"provisioner": &ResourceProvisionerPlugin{F: opts.ProvisionerFunc},
+		"provider": &ResourceProviderPlugin{
+			ResourceProvider: opts.ProviderFunc,
+		},
+		"provisioner": &ResourceProvisionerPlugin{
+			ResourceProvisioner: opts.ProvisionerFunc,
+		},
 	}
 }
+
+func pluginSet(opts *ServeOpts) map[int]plugin.PluginSet {
+	// Set the legacy netrpc plugins at version 4.
+	// The oldest version is returned in when executed by a legacy go-plugin
+	// client.
+	plugins := map[int]plugin.PluginSet{
+		4: pluginMap(opts),
+	}
+
+	// add the new protocol versions if they're configured
+	if opts.GRPCProviderFunc != nil || opts.GRPCProvisionerFunc != nil {
+		plugins[5] = plugin.PluginSet{
+			"provider": &GRPCProviderPlugin{
+				GRPCProvider: opts.GRPCProviderFunc,
+			},
+			"provisioner": &GRPCProvisionerPlugin{
+				GRPCProvisioner: opts.GRPCProvisionerFunc,
+			},
+		}
+	}
+	return plugins
+}