update to start a new process for each plugin

Modify the plugin factories to create a new plugin process for each
individual plugin.

command/plugins.go

@@ -84,8 +84,7 @@ func (r *multiVersionProviderResolver) ResolveProviders(
 				continue
 			}
 
-			client := tfplugin.Client(newest)
-			factories[name] = providerFactory(client)
+			factories[name] = providerFactory(newest)
 		} else {
 			msg := fmt.Sprintf("provider.%s: no suitable version installed", name)
 
@@ -332,7 +331,7 @@ func (m *Meta) provisionerFactories() map[string]terraform.ProvisionerFactory {
 			log.Printf("[WARN] failed to build command line for internal plugin %q: %s", name, err)
 			continue
 		}
-		factories[name] = provisionerFactory(client)
+		factories[name] = internalProvisionerFactory(client)
 	}
 
 	byName := plugins.ByName()
@@ -341,8 +340,8 @@ func (m *Meta) provisionerFactories() map[string]terraform.ProvisionerFactory {
 		// by name, we're guaranteed that the metas in our set all have
 		// valid versions and that there's at least one meta.
 		newest := metas.Newest()
-		client := tfplugin.Client(newest)
-		factories[name] = provisionerFactory(client)
+
+		factories[name] = provisionerFactory(newest)
 	}
 
 	return factories
@@ -369,8 +368,9 @@ func internalPluginClient(kind, name string) (*plugin.Client, error) {
 	return plugin.NewClient(cfg), nil
 }
 
-func providerFactory(client *plugin.Client) providers.Factory {
+func providerFactory(meta discovery.PluginMeta) providers.Factory {
 	return func() (providers.Interface, error) {
+		client := tfplugin.Client(meta)
 		// Request the RPC client so we can get the provider
 		// so we can build the actual RPC-implemented provider.
 		rpcClient, err := client.Client()
@@ -383,24 +383,41 @@ func providerFactory(client *plugin.Client) providers.Factory {
 			return nil, err
 		}
 
-		return raw.(providers.Interface), nil
+		// store the client so that the plugin can kill the child process
+		p := raw.(*tfplugin.GRPCProvider)
+		p.PluginClient = client
+		return p, nil
 	}
 }
 
-func provisionerFactory(client *plugin.Client) terraform.ProvisionerFactory {
+func provisionerFactory(meta discovery.PluginMeta) terraform.ProvisionerFactory {
 	return func() (provisioners.Interface, error) {
-		// Request the RPC client so we can get the provisioner
-		// so we can build the actual RPC-implemented provisioner.
-		rpcClient, err := client.Client()
-		if err != nil {
-			return nil, err
-		}
+		client := tfplugin.Client(meta)
+		return newProvisionerClient(client)
+	}
+}
 
-		raw, err := rpcClient.Dispense(tfplugin.ProvisionerPluginName)
-		if err != nil {
-			return nil, err
-		}
+func internalProvisionerFactory(client *plugin.Client) terraform.ProvisionerFactory {
+	return func() (provisioners.Interface, error) {
+		return newProvisionerClient(client)
+	}
+}
+
+func newProvisionerClient(client *plugin.Client) (provisioners.Interface, error) {
+	// Request the RPC client so we can get the provisioner
+	// so we can build the actual RPC-implemented provisioner.
+	rpcClient, err := client.Client()
+	if err != nil {
+		return nil, err
+	}
 
-		return raw.(provisioners.Interface), nil
+	raw, err := rpcClient.Dispense(tfplugin.ProvisionerPluginName)
+	if err != nil {
+		return nil, err
 	}
+
+	// store the client so that the plugin can kill the child process
+	p := raw.(*tfplugin.GRPCProvisioner)
+	p.PluginClient = client
+	return p, nil
 }

plugin/grpc_provider.go

@@ -25,7 +25,6 @@ type GRPCProviderPlugin struct {
 
 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
@@ -41,7 +40,11 @@ func (p *GRPCProviderPlugin) GRPCServer(broker *plugin.GRPCBroker, s *grpc.Serve
 // terraform provioders types and the grpc proto types, directly converting
 // between the two.
 type GRPCProvider struct {
-	conn   *grpc.ClientConn
+	// PluginClient provides a reference to the plugin.Client which controls the plugin process.
+	// This allows the GRPCProvider a way to shutdown the plugin process.
+	PluginClient *plugin.Client
+
+	// Proto client use to make the grpc service calls.
 	client proto.ProviderClient
 
 	// this context is created by the plugin package, and is canceled when the
@@ -495,8 +498,13 @@ func (p *GRPCProvider) ReadDataSource(r providers.ReadDataSourceRequest) (resp p
 }
 
 // closing the grpc connection is final, and terraform will call it at the end of every phase.
-// FIXME: do we need this, and if so, how do we fix it?
 func (p *GRPCProvider) Close() error {
-	log.Printf("[TRACE] GRPCProvider: Close")
+	// check this since it's not automatically inserted during plugin creation
+	if p.PluginClient == nil {
+		log.Println("[DEBUG] provider has no plugin.Client")
+		return nil
+	}
+
+	p.PluginClient.Kill()
 	return nil
 }

plugin/grpc_provisioner.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"io"
+	"log"
 	"sync"
 
 	plugin "github.com/hashicorp/go-plugin"
@@ -24,7 +25,6 @@ type GRPCProvisionerPlugin struct {
 
 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
@@ -37,7 +37,10 @@ func (p *GRPCProvisionerPlugin) GRPCServer(broker *plugin.GRPCBroker, s *grpc.Se
 
 // provisioners.Interface grpc implementation
 type GRPCProvisioner struct {
-	conn   *grpc.ClientConn
+	// PluginClient provides a reference to the plugin.Client which controls the plugin process.
+	// This allows the GRPCProvider a way to shutdown the plugin process.
+	PluginClient *plugin.Client
+
 	client proto.ProvisionerClient
 	ctx    context.Context
 
@@ -163,5 +166,12 @@ 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")
+		return nil
+	}
+
+	p.PluginClient.Kill()
 	return nil
 }

terraform/context_components.go

@@ -33,7 +33,7 @@ type basicComponentFactory struct {
 
 func (c *basicComponentFactory) ResourceProviders() []string {
 	result := make([]string, len(c.providers))
-	for k, _ := range c.providers {
+	for k := range c.providers {
 		result = append(result, k)
 	}
 
@@ -42,7 +42,7 @@ func (c *basicComponentFactory) ResourceProviders() []string {
 
 func (c *basicComponentFactory) ResourceProvisioners() []string {
 	result := make([]string, len(c.provisioners))
-	for k, _ := range c.provisioners {
+	for k := range c.provisioners {
 		result = append(result, k)
 	}