Add parsesvcname package for getting service name

truss/parsesvcname/parsesvcname.go

@@ -0,0 +1,86 @@
+package parsesvcname
+
+import (
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/TuneLab/go-truss/svcdef"
+	"github.com/TuneLab/go-truss/truss/execprotoc"
+	"github.com/pkg/errors"
+)
+
+// FromPaths accepts the paths of protobuf definition files and returns the
+// name of the service in that protobuf definition file.
+func FromPaths(gopath string, protoDefPaths []string) (string, error) {
+	td, err := ioutil.TempDir("", "parsesvcname")
+	defer os.RemoveAll(td)
+	if err != nil {
+		return "", errors.Wrap(err, "failed to create temporary directory for .pb.go files")
+	}
+	err = execprotoc.GeneratePBDotGo(protoDefPaths, []string{gopath}, td)
+	if err != nil {
+		return "", errors.Wrap(err, "failed to generate .pb.go files from protobuf definition files")
+	}
+
+	// Get path names of .pb.go files
+	pbgoPaths := []string{}
+	for _, p := range protoDefPaths {
+		base := filepath.Base(p)
+		barename := strings.TrimSuffix(base, filepath.Ext(p))
+		pbgp := filepath.Join(td, barename+".pb.go")
+		pbgoPaths = append(pbgoPaths, pbgp)
+	}
+
+	// Open all .pb.go files and store in map to be passed to svcdef.New()
+	openFiles := func(paths []string) (map[string]io.Reader, error) {
+		rv := map[string]io.Reader{}
+		for _, p := range paths {
+			reader, err := os.Open(p)
+			if err != nil {
+				return nil, errors.Wrapf(err, "cannot open file %q", p)
+			}
+			rv[p] = reader
+		}
+		return rv, nil
+	}
+	pbgoFiles, err := openFiles(pbgoPaths)
+	if err != nil {
+		return "", errors.Wrap(err, "cannot open all .pb.go files")
+	}
+	pbFiles, err := openFiles(protoDefPaths)
+	if err != nil {
+		return "", errors.Wrap(err, "cannot open all .proto files")
+	}
+
+	sd, err := svcdef.New(pbgoFiles, pbFiles)
+	if err != nil {
+		return "", errors.Wrapf(err, "failed to create service definition; did you pass ALL the protobuf files to truss?")
+	}
+
+	return sd.Service.Name, nil
+}
+
+func FromReaders(gopath string, protoDefReaders []io.Reader) (string, error) {
+	protoDir, err := ioutil.TempDir("", "parsesvcname-fromreaders")
+	if err != nil {
+		return "", errors.Wrap(err, "failed to create temporary directory for protobuf files")
+	}
+	// Ensures all the temporary files are removed
+	defer os.RemoveAll(protoDir)
+
+	protoDefPaths := []string{}
+	for _, rdr := range protoDefReaders {
+		f, err := ioutil.TempFile(protoDir, "parsesvcname-fromreader")
+		_, err = io.Copy(f, rdr)
+		if err != nil {
+			return "", errors.Wrap(err, "couldn't copy contents of our proto file into the os.File: ")
+		}
+		path := f.Name()
+		f.Close()
+		protoDefPaths = append(protoDefPaths, path)
+	}
+	return FromPaths(gopath, protoDefPaths)
+}

truss/parsesvcname/parsesvcname_test.go

@@ -0,0 +1,114 @@
+package parsesvcname
+
+import (
+	"io"
+	"io/ioutil"
+	"os"
+	"strings"
+	"testing"
+)
+
+// Provide a basic proto file to test that FromPaths returns the name of the
+// service in the file at the provided path.
+func TestFromPaths(t *testing.T) {
+	protoStr := `
+	syntax = "proto3";
+	package echo;
+
+	import "github.com/TuneLab/go-genproto/googleapis/api/serviceconfig/annotations.proto";
+
+	service BounceEcho {
+	  rpc Echo (EchoRequest) returns (EchoResponse) {
+		option (google.api.http) = {
+			get: "/echo"
+		  };
+	  }
+	}
+	message EchoRequest {
+	  string In = 1;
+	}
+	message EchoResponse {
+	  string Out = 1;
+	}
+	`
+	protoDir, err := ioutil.TempDir("", "parsesvcname-test")
+	if err != nil {
+		t.Fatal("cannot create temp directory to store proto definition: ", err)
+	}
+	defer os.RemoveAll(protoDir)
+	f, err := ioutil.TempFile(protoDir, "trusstest")
+	_, err = io.Copy(f, strings.NewReader(protoStr))
+	if err != nil {
+		t.Fatal("couldn't copy contents of our proto file into the os.File: ", err)
+	}
+	path := f.Name()
+	f.Close()
+
+	svcname, err := FromPaths(os.Getenv("GOPATH"), []string{path})
+	if err != nil {
+		t.Fatal("failed to get service name from path: ", err)
+	}
+
+	if got, want := svcname, "BounceEcho"; got != want {
+		t.Fatalf("got != want; got = %q, want = %q", got, want)
+	}
+}
+
+// Provide a basic protobuf file to FromReader to ensure it returns the service
+// name we expect.
+func TestFromReader(t *testing.T) {
+	protoStr := `
+	syntax = "proto3";
+	package echo;
+
+	import "github.com/TuneLab/go-genproto/googleapis/api/serviceconfig/annotations.proto";
+
+	service BounceEcho {
+	  rpc Echo (EchoRequest) returns (EchoResponse) {
+		option (google.api.http) = {
+			get: "/echo"
+		  };
+	  }
+	}
+	message EchoRequest {
+	  string In = 1;
+	}
+	message EchoResponse {
+	  string Out = 1;
+	}
+	`
+	svcname, err := FromReaders(os.Getenv("GOPATH"), []io.Reader{strings.NewReader(protoStr)})
+	if err != nil {
+		t.Fatal("failed to get service name from path: ", err)
+	}
+
+	if got, want := svcname, "BounceEcho"; got != want {
+		t.Fatalf("got != want; got = %q, want = %q", got, want)
+	}
+}
+
+// Ensure that passing a protobuf file that's not importing google annotations will function properly.
+func TestNoAnnotations(t *testing.T) {
+	protoStr := `
+	syntax = "proto3";
+	package echo;
+
+	service BounceEcho {
+	  rpc Echo (EchoRequest) returns (EchoResponse) {}
+	}
+	message EchoRequest {
+	  string In = 1;
+	}
+	message EchoResponse {
+	  string Out = 1;
+	}
+	`
+	svcname, err := FromReaders(os.Getenv("GOPATH"), []io.Reader{strings.NewReader(protoStr)})
+	if err != nil {
+		t.Fatal("failed to get service name from path: ", err)
+	}
+
+	if got, want := svcname, "BounceEcho"; got != want {
+		t.Fatalf("got != want; got = %q, want = %q", got, want)
+	}
+}