bootcfg/rpc: Convert errors to gRPC canonical errors in rpc pkg

bootcfg/rpc/errors.go

@@ -0,0 +1,30 @@
+package rpc
+
+import (
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+
+	"github.com/coreos/coreos-baremetal/bootcfg/server"
+)
+
+var (
+	// work around go vet false positive https://github.com/grpc/grpc-go/issues/90
+	grpcErrorf           = grpc.Errorf
+	errNoMatchingGroup   = grpcErrorf(codes.NotFound, "bootcfg: No matching Group")
+	errNoMatchingProfile = grpcErrorf(codes.NotFound, "bootcfg: No matching Profile")
+)
+
+// grpcError transforms an error into a gRPC errors with canonical error codes.
+func grpcError(err error) error {
+	if err == nil {
+		return err
+	}
+	switch err {
+	case server.ErrNoMatchingGroup:
+		return errNoMatchingGroup
+	case server.ErrNoMatchingProfile:
+		return errNoMatchingProfile
+	default:
+		return grpcErrorf(codes.Unknown, err.Error())
+	}
+}

bootcfg/rpc/errors_test.go

@@ -0,0 +1,27 @@
+package rpc
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"google.golang.org/grpc/codes"
+
+	"github.com/coreos/coreos-baremetal/bootcfg/server"
+)
+
+func TestGRPCError(t *testing.T) {
+	cases := []struct {
+		input  error
+		output error
+	}{
+		{nil, nil},
+		{server.ErrNoMatchingGroup, errNoMatchingGroup},
+		{server.ErrNoMatchingProfile, errNoMatchingProfile},
+		{errors.New("other error"), grpcErrorf(codes.Unknown, "other error")},
+	}
+	for _, c := range cases {
+		err := grpcError(c.input)
+		assert.Equal(t, c.output, err)
+	}
+}

bootcfg/rpc/groups.go

@@ -21,10 +21,10 @@ func newGroupServer(s server.Server) rpcpb.GroupsServer {
 
 func (s *groupServer) GroupGet(ctx context.Context, req *pb.GroupGetRequest) (*pb.GroupGetResponse, error) {
 	group, err := s.srv.GroupGet(ctx, req)
-	return &pb.GroupGetResponse{Group: group}, err
+	return &pb.GroupGetResponse{Group: group}, grpcError(err)
 }
 
 func (s *groupServer) GroupList(ctx context.Context, req *pb.GroupListRequest) (*pb.GroupListResponse, error) {
 	groups, err := s.srv.GroupList(ctx, req)
-	return &pb.GroupListResponse{Groups: groups}, err
+	return &pb.GroupListResponse{Groups: groups}, grpcError(err)
 }

bootcfg/rpc/profiles.go

@@ -22,15 +22,15 @@ func newProfileServer(s server.Server) rpcpb.ProfilesServer {
 func (s *profileServer) ProfilePut(ctx context.Context, req *pb.ProfilePutRequest) (*pb.ProfilePutResponse, error) {
 	_, err := s.srv.ProfilePut(ctx, req)
 	// TODO(dghubble): Decide on create/put and response(s).
-	return &pb.ProfilePutResponse{}, err
+	return &pb.ProfilePutResponse{}, grpcError(err)
 }
 
 func (s *profileServer) ProfileGet(ctx context.Context, req *pb.ProfileGetRequest) (*pb.ProfileGetResponse, error) {
 	profile, err := s.srv.ProfileGet(ctx, req)
-	return &pb.ProfileGetResponse{Profile: profile}, err
+	return &pb.ProfileGetResponse{Profile: profile}, grpcError(err)
 }
 
 func (s *profileServer) ProfileList(ctx context.Context, req *pb.ProfileListRequest) (*pb.ProfileListResponse, error) {
 	profiles, err := s.srv.ProfileList(ctx, req)
-	return &pb.ProfileListResponse{Profiles: profiles}, err
+	return &pb.ProfileListResponse{Profiles: profiles}, grpcError(err)
 }

bootcfg/rpc/select.go

@@ -22,10 +22,10 @@ func newSelectServer(s server.Server) rpcpb.SelectServer {
 
 func (s *selectServer) SelectGroup(ctx context.Context, req *pb.SelectGroupRequest) (*pb.SelectGroupResponse, error) {
 	group, err := s.srv.SelectGroup(ctx, req)
-	return &pb.SelectGroupResponse{Group: group}, err
+	return &pb.SelectGroupResponse{Group: group}, grpcError(err)
 }
 
 func (s *selectServer) SelectProfile(ctx context.Context, req *pb.SelectProfileRequest) (*pb.SelectProfileResponse, error) {
 	profile, err := s.srv.SelectProfile(ctx, req)
-	return &pb.SelectProfileResponse{Profile: profile}, err
+	return &pb.SelectProfileResponse{Profile: profile}, grpcError(err)
 }

bootcfg/server/server.go

@@ -11,9 +11,10 @@ import (
 	"github.com/coreos/coreos-baremetal/bootcfg/storage/storagepb"
 )
 
+// Possible service errors
 var (
-	errNoMatchingGroup = errors.New("bootcfg: No matching Group")
-	errNoProfileFound  = errors.New("bootcfg: No Profile found")
+	ErrNoMatchingGroup   = errors.New("bootcfg: No matching Group")
+	ErrNoMatchingProfile = errors.New("bootcfg: No matching Profile")
 )
 
 // Server defines a bootcfg server lib.
@@ -115,7 +116,7 @@ func (s *server) SelectGroup(ctx context.Context, req *pb.SelectGroupRequest) (*
 			return group, nil
 		}
 	}
-	return nil, errNoMatchingGroup
+	return nil, ErrNoMatchingGroup
 }
 
 func (s *server) SelectProfile(ctx context.Context, req *pb.SelectProfileRequest) (*storagepb.Profile, error) {
@@ -126,9 +127,9 @@ func (s *server) SelectProfile(ctx context.Context, req *pb.SelectProfileRequest
 		if err == nil {
 			return profile, nil
 		}
-		return nil, errNoProfileFound
+		return nil, ErrNoMatchingProfile
 	}
-	return nil, errNoMatchingGroup
+	return nil, ErrNoMatchingGroup
 }
 
 // IgnitionGet gets an Ignition Config template by name.

bootcfg/server/server_test.go

@@ -23,9 +23,9 @@ func TestSelectGroup(t *testing.T) {
 		expectedErr   error
 	}{
 		{store, map[string]string{"uuid": "a1b2c3d4"}, fake.Group, nil},
-		{store, nil, nil, errNoMatchingGroup},
+		{store, nil, nil, ErrNoMatchingGroup},
 		// no groups in the store
-		{&fake.EmptyStore{}, map[string]string{"a": "b"}, nil, errNoMatchingGroup},
+		{&fake.EmptyStore{}, map[string]string{"a": "b"}, nil, ErrNoMatchingGroup},
 	}
 	for _, c := range cases {
 		srv := NewServer(&Config{c.store})