Use providers.Interface instead of terraform.ResourceProvider

In Terraform v0.12, the provider protocol version is upgraded from 4 to 5,
and its implementation uses GRPCProvider.

command/autocomplete.go

@@ -21,11 +21,9 @@ func (m *Meta) completePredictResourceType() complete.Predictor {
 
 		defer client.Kill()
 
-		res := client.Resources()
-
-		resourceTypes := []string{}
-		for _, r := range res {
-			resourceTypes = append(resourceTypes, r.Name)
+		resourceTypes, err := client.ResourceTypes()
+		if err != nil {
+			return nil
 		}
 
 		return resourceTypes
@@ -49,14 +47,11 @@ func (m *Meta) completePredictDataSource() complete.Predictor {
 
 		defer client.Kill()
 
-		res := client.DataSources()
-
-		dataSources := []string{}
-		for _, r := range res {
-			dataSources = append(dataSources, r.Name)
+		dataSources, err := client.DataSources()
+		if err != nil {
+			return nil
 		}
 
 		return dataSources
-
 	})
 }

command/data_list.go

@@ -29,11 +29,10 @@ func (c *DataListCommand) Run(args []string) int {
 
 	defer client.Kill()
 
-	res := client.DataSources()
-
-	dataSources := []string{}
-	for _, r := range res {
-		dataSources = append(dataSources, r.Name)
+	dataSources, err := client.DataSources()
+	if err != nil {
+		c.UI.Error(err.Error())
+		return 1
 	}
 
 	c.UI.Output(strings.Join(dataSources, "\n"))

command/resource_list.go

@@ -29,11 +29,10 @@ func (c *ResourceListCommand) Run(args []string) int {
 
 	defer client.Kill()
 
-	res := client.Resources()
-
-	resourceTypes := []string{}
-	for _, r := range res {
-		resourceTypes = append(resourceTypes, r.Name)
+	resourceTypes, err := client.ResourceTypes()
+	if err != nil {
+		c.UI.Error(err.Error())
+		return 1
 	}
 
 	c.UI.Output(strings.Join(resourceTypes, "\n"))

tfschema/client.go

@@ -8,18 +8,19 @@ import (
 	"path/filepath"
 	"reflect"
 	"runtime"
+	"sort"
 	"strings"
 
 	"github.com/hashicorp/terraform/plugin"
 	"github.com/hashicorp/terraform/plugin/discovery"
-	"github.com/hashicorp/terraform/terraform"
+	"github.com/hashicorp/terraform/providers"
 	"github.com/mitchellh/go-homedir"
 )
 
 // Client represents a tfschema Client.
 type Client struct {
-	// provider is a resource provider of Terraform.
-	provider terraform.ResourceProvider
+	// provider is a provider interface of Terraform.
+	provider providers.Interface
 	// pluginClient is a pointer to plugin client instance.
 	// The type of pluginClient is
 	// *github.com/hashicorp/terraform/vendor/github.com/hashicorp/go-plugin.Client.
@@ -38,17 +39,17 @@ func NewClient(providerName string) (*Client, error) {
 
 	// initialize a plugin client.
 	pluginClient := plugin.Client(*pluginMeta)
-	rpcClient, err := pluginClient.Client()
+	gRPCClient, err := pluginClient.Client()
 	if err != nil {
 		return nil, fmt.Errorf("Failed to initialize plugin: %s", err)
 	}
 
 	// create a new resource provider.
-	raw, err := rpcClient.Dispense(plugin.ProviderPluginName)
+	raw, err := gRPCClient.Dispense(plugin.ProviderPluginName)
 	if err != nil {
 		return nil, fmt.Errorf("Failed to dispense plugin: %s", err)
 	}
-	provider := raw.(terraform.ResourceProvider)
+	provider := raw.(*plugin.GRPCProvider)
 
 	return &Client{
 		provider:     provider,
@@ -120,68 +121,77 @@ func pluginDirs() ([]string, error) {
 
 // GetProviderSchema returns a type definiton of provider schema.
 func (c *Client) GetProviderSchema() (*Block, error) {
-	req := &terraform.ProviderSchemaRequest{
-		ResourceTypes: []string{},
-		DataSources:   []string{},
+	res := c.provider.GetSchema()
+	if res.Diagnostics.HasErrors() {
+		return nil, fmt.Errorf("Failed to get schema from provider: %s", res.Diagnostics.Err())
 	}
 
-	res, err := c.provider.GetSchema(req)
-	if err != nil {
-		return nil, fmt.Errorf("Failed to get schema from provider: %s", err)
-	}
-
-	b := NewBlock(res.Provider)
+	b := NewBlock(res.Provider.Block)
 	return b, nil
 }
 
 // GetResourceTypeSchema returns a type definiton of resource type.
 func (c *Client) GetResourceTypeSchema(resourceType string) (*Block, error) {
-	req := &terraform.ProviderSchemaRequest{
-		ResourceTypes: []string{resourceType},
-		DataSources:   []string{},
+	res := c.provider.GetSchema()
+	if res.Diagnostics.HasErrors() {
+		return nil, fmt.Errorf("Failed to get schema from provider: %s", res.Diagnostics.Err())
 	}
 
-	res, err := c.provider.GetSchema(req)
-	if err != nil {
-		return nil, fmt.Errorf("Failed to get schema from provider: %s", err)
-	}
-
-	if res.ResourceTypes[resourceType] == nil {
+	schema, ok := res.ResourceTypes[resourceType]
+	if !ok {
 		return nil, fmt.Errorf("Failed to find resource type: %s", resourceType)
 	}
 
-	b := NewBlock(res.ResourceTypes[resourceType])
+	b := NewBlock(schema.Block)
 	return b, nil
 }
 
 // GetDataSourceSchema returns a type definiton of data source.
 func (c *Client) GetDataSourceSchema(dataSource string) (*Block, error) {
-	req := &terraform.ProviderSchemaRequest{
-		ResourceTypes: []string{},
-		DataSources:   []string{dataSource},
-	}
-
-	res, err := c.provider.GetSchema(req)
-	if err != nil {
-		return nil, fmt.Errorf("Failed to get schema from provider: %s", err)
+	res := c.provider.GetSchema()
+	if res.Diagnostics.HasErrors() {
+		return nil, fmt.Errorf("Failed to get schema from provider: %s", res.Diagnostics.Err())
 	}
 
-	if res.DataSources[dataSource] == nil {
+	schema, ok := res.DataSources[dataSource]
+	if !ok {
 		return nil, fmt.Errorf("Failed to find data source: %s", dataSource)
 	}
 
-	b := NewBlock(res.DataSources[dataSource])
+	b := NewBlock(schema.Block)
 	return b, nil
 }
 
-// Resources returns a list of resource types.
-func (c *Client) Resources() []terraform.ResourceType {
-	return c.provider.Resources()
+// ResourceTypes returns a list of resource types.
+func (c *Client) ResourceTypes() ([]string, error) {
+	res := c.provider.GetSchema()
+	if res.Diagnostics.HasErrors() {
+		return nil, fmt.Errorf("Failed to get schema from provider: %s", res.Diagnostics.Err())
+	}
+
+	keys := make([]string, 0, len(res.ResourceTypes))
+	for k := range res.ResourceTypes {
+		keys = append(keys, k)
+	}
+
+	sort.Strings(keys)
+	return keys, nil
 }
 
 // DataSources returns a list of data sources.
-func (c *Client) DataSources() []terraform.DataSource {
-	return c.provider.DataSources()
+func (c *Client) DataSources() ([]string, error) {
+	res := c.provider.GetSchema()
+	if res.Diagnostics.HasErrors() {
+		return nil, fmt.Errorf("Failed to get schema from provider: %s", res.Diagnostics.Err())
+	}
+
+	keys := make([]string, 0, len(res.DataSources))
+	for k := range res.DataSources {
+		keys = append(keys, k)
+	}
+
+	sort.Strings(keys)
+	return keys, nil
 }
 
 // Kill kills a process of the plugin.