protocol: define supported languages endpoint; add language aliases

Signed-off-by: Denys Smirnov <denys@sourced.tech>

Author: Denys Smirnov

build/build.go

@@ -257,9 +257,7 @@ func (d *Driver) FillManifest(dest string) error {
 		return err
 	}
 	m.Version = vers
-
-	now := time.Now().UTC()
-	m.Build = &now
+	m.Build = time.Now().UTC()
 
 	bm, err := d.readBuildManifest()
 	if err != nil {

build/build_test.go

@@ -13,6 +13,7 @@ import (
 	"google.golang.org/grpc"
 
 	"github.com/bblfsh/sdk/v3/driver"
+	"github.com/bblfsh/sdk/v3/driver/manifest"
 	"github.com/bblfsh/sdk/v3/internal/docker"
 	"github.com/bblfsh/sdk/v3/protocol"
 	"github.com/bblfsh/sdk/v3/uast/nodes"
@@ -155,3 +156,11 @@ func (d *dockerDriver) Close() error {
 func (d *dockerDriver) Parse(ctx context.Context, src string, opts *driver.ParseOptions) (nodes.Node, error) {
 	return d.d.Parse(ctx, src, opts)
 }
+
+func (d *dockerDriver) Version(ctx context.Context) (driver.Version, error) {
+	return d.d.Version(ctx)
+}
+
+func (d *dockerDriver) Languages(ctx context.Context) ([]manifest.Manifest, error) {
+	return d.d.Languages(ctx)
+}

driver/driver.go

@@ -4,6 +4,7 @@ package driver
 import (
 	"context"
 	"fmt"
+	"time"
 
 	"gopkg.in/src-d/go-errors.v1"
 
@@ -27,6 +28,11 @@ var (
 	ErrModeNotSupported = errors.NewKind("transform mode not supported")
 )
 
+const (
+	// ManifestLocation is the path of the manifest file in the driver image.
+	ManifestLocation = "/opt/driver/etc/" + manifest.Filename
+)
+
 // ErrMulti joins multiple errors.
 type ErrMulti = derrors.ErrMulti
 
@@ -87,13 +93,24 @@ type Driver interface {
 	// Native driver failures are indicated by ErrDriverFailure and UAST transformation are indicated by ErrTransformFailure.
 	// All other errors indicate a protocol or server failure.
 	Parse(ctx context.Context, src string, opts *ParseOptions) (nodes.Node, error)
+
+	// Version returns a version of the driver or the server, depending where is this interface is implemented.
+	Version(ctx context.Context) (Version, error)
+
+	// Languages returns a list of manifests for languages supported by this driver or the server.
+	Languages(ctx context.Context) ([]manifest.Manifest, error)
+}
+
+// Version information for driver or the server.
+type Version struct {
+	Version string    // the version label for the driver, e.g., 'v1.2.3-tag' or 'undefined'
+	Build   time.Time // the timestamp when the driver was built
 }
 
 // DriverModule is an interface for a driver instance.
 type DriverModule interface {
 	Module
 	Driver
-	Manifest() (manifest.Manifest, error)
 }
 
 // Native is a base interface of a language driver that returns a native AST.

driver/impl.go

@@ -73,7 +73,15 @@ func (d *driverImpl) Parse(rctx context.Context, src string, opts *ParseOptions)
 	return ast, err
 }
 
-// Manifest returns a driver manifest.
-func (d *driverImpl) Manifest() (manifest.Manifest, error) {
-	return *d.m, nil // TODO: clone
+// Version returns driver version.
+func (d *driverImpl) Version(ctx context.Context) (Version, error) {
+	return Version{
+		Version: d.m.Version,
+		Build:   d.m.Build,
+	}, nil
+}
+
+// Languages returns a single driver manifest for the language supported by the driver.
+func (d *driverImpl) Languages(ctx context.Context) ([]manifest.Manifest, error) {
+	return []manifest.Manifest{*d.m}, nil // TODO: clone
 }

driver/manifest/manifest.go

@@ -95,8 +95,9 @@ type Documentation struct {
 type Manifest struct {
 	Name          string            `toml:"name"` // human-readable name
 	Language      string            `toml:"language"`
+	Aliases       []string          `toml:"aliases"` // language name aliases, see Enry/Linguist
 	Version       string            `toml:"version,omitempty" json:",omitempty"`
-	Build         *time.Time        `toml:"build,omitempty" json:",omitempty"`
+	Build         time.Time         `toml:"build,omitempty" json:",omitempty"`
 	Status        DevelopmentStatus `toml:"status"`
 	SDKVersion    string            `toml:"-"` // read from go.mod
 	Documentation *Documentation    `toml:"documentation,omitempty" json:",omitempty"`

driver/manifest/manifest_test.go

@@ -12,6 +12,7 @@ import (
 var fixture = `
 name = "Foo"
 language = "foo"
+build = 0001-01-01T00:00:00Z
 status = ""
 features = ["ast", "uast", "roles"]
 

driver/server/common.go

@@ -11,7 +11,7 @@ var DefaultDriver driver.Native = native.NewDriver("")
 var (
 	// ManifestLocation location of the manifest file. Should not override
 	// this variable unless you know what are you doing.
-	ManifestLocation = "/opt/driver/etc/" + manifest.Filename
+	ManifestLocation = driver.ManifestLocation
 )
 
 // Run is a common main function used as an entry point for drivers.

driver/server/grpc.go

@@ -58,32 +58,56 @@ func newDriverManifest(manifest *manifest.Manifest) protocol1.DriverManifest {
 	}
 }
 
+func containsLang(lang string, list []manifest.Manifest) bool {
+	for _, m := range list {
+		if m.Language == lang {
+			return true
+		}
+		for _, l := range m.Aliases {
+			if l == lang {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// SupportedLanguages implements protocol1.Service.
 func (s service) SupportedLanguages(_ *protocol1.SupportedLanguagesRequest) *protocol1.SupportedLanguagesResponse {
-	m, _ := s.d.Manifest()
-	return &protocol1.SupportedLanguagesResponse{Languages: []protocol1.DriverManifest{
-		newDriverManifest(&m),
-	}}
+	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+	defer cancel()
+	list, err := s.d.Languages(ctx)
+	if err != nil {
+		return &protocol1.SupportedLanguagesResponse{Response: errResp(err)}
+	}
+	resp := &protocol1.SupportedLanguagesResponse{
+		Response: protocol1.Response{Status: protocol1.Ok},
+	}
+	for _, m := range list {
+		resp.Languages = append(resp.Languages, newDriverManifest(&m))
+	}
+	return resp
 }
 
 func (s service) parse(mode driver.Mode, req *protocol1.ParseRequest) (nodes.Node, protocol1.Response) {
 	start := time.Now()
-	m, err := s.d.Manifest()
+	ctx := context.Background()
+	if req.Timeout > 0 {
+		var cancel func()
+		ctx, cancel = context.WithTimeout(ctx, req.Timeout)
+		defer cancel()
+	}
+	list, err := s.d.Languages(ctx)
 	if err != nil {
 		r := errResp(err)
 		r.Elapsed = time.Since(start)
 		return nil, r
 	}
-	if req.Language != m.Language {
+	if !containsLang(req.Language, list) {
 		r := errResp(ErrUnsupportedLanguage.New(req.Language))
 		r.Elapsed = time.Since(start)
 		return nil, r
 	}
-	ctx := context.Background()
-	if req.Timeout > 0 {
-		var cancel func()
-		ctx, cancel = context.WithTimeout(ctx, req.Timeout)
-		defer cancel()
-	}
 	ast, err := s.d.Parse(ctx, req.Content, &driver.ParseOptions{
 		Mode:     mode,
 		Language: req.Language,
@@ -100,6 +124,7 @@ func (s service) parse(mode driver.Mode, req *protocol1.ParseRequest) (nodes.Nod
 	return ast, r
 }
 
+// Parse implements protocol1.Service.
 func (s service) Parse(req *protocol1.ParseRequest) *protocol1.ParseResponse {
 	ast, resp := s.parse(driver.ModeAnnotated, req)
 	if resp.Status != protocol1.Ok {
@@ -119,6 +144,7 @@ func (s service) Parse(req *protocol1.ParseRequest) *protocol1.ParseResponse {
 	}
 }
 
+// NativeParse implements protocol1.Service.
 func (s service) NativeParse(req *protocol1.NativeParseRequest) *protocol1.NativeParseResponse {
 	ast, resp := s.parse(driver.ModeNative, (*protocol1.ParseRequest)(req))
 	if resp.Status != protocol1.Ok {
@@ -137,14 +163,17 @@ func (s service) NativeParse(req *protocol1.NativeParseRequest) *protocol1.Nativ
 	}
 }
 
+// Version implements protocol1.Service.
 func (s service) Version(req *protocol1.VersionRequest) *protocol1.VersionResponse {
-	m, _ := s.d.Manifest()
+	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+	defer cancel()
 
-	r := &protocol1.VersionResponse{
-		Version: m.Version,
+	m, err := s.d.Version(ctx)
+	if err != nil {
+		return &protocol1.VersionResponse{Response: errResp(err)}
 	}
-	if m.Build != nil {
-		r.Build = *m.Build
+	return &protocol1.VersionResponse{
+		Version: m.Version,
+		Build:   m.Build,
 	}
-	return r
 }

driver/server/server.go

@@ -1,7 +1,9 @@
 package server
 
 import (
+	"context"
 	"flag"
+	"fmt"
 	"io"
 	"net"
 	"os"
@@ -81,10 +83,13 @@ func (s *Server) initialize() error {
 	if err := s.initializeLogger(); err != nil {
 		return err
 	}
-	m, err := s.d.Manifest()
+	list, err := s.d.Languages(context.Background())
 	if err != nil {
 		return err
+	} else if len(list) != 1 {
+		return fmt.Errorf("expected exactly one manifest, got %d", len(list))
 	}
+	m := list[0]
 	if err := s.initializeTracing(m.Language + "-driver"); err != nil {
 		return err
 	}
@@ -96,7 +101,7 @@ func (s *Server) initialize() error {
 	}
 
 	build := "unknown"
-	if m.Build != nil {
+	if !m.Build.IsZero() {
 		build = m.Build.Format("2006-01-02T15:04:05Z")
 	}
 	s.Logger.Infof("%s-driver version: %s (build: %s)",