open-consul/agent/grpc-external/services/resource/read.go

package resource

import (
	"context"
	"errors"

	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"

	"github.com/hashicorp/consul/internal/storage"
	"github.com/hashicorp/consul/proto-public/pbresource"
)

func (s *Server) Read(ctx context.Context, req *pbresource.ReadRequest) (*pbresource.ReadResponse, error) {
	// check type exists
	if _, err := s.resolveType(req.Id.Type); err != nil {
		return nil, err
	}

	resource, err := s.backend.Read(ctx, readConsistencyFrom(ctx), req.Id)
	if err != nil {
		if errors.Is(err, storage.ErrNotFound) {
			return nil, status.Error(codes.NotFound, err.Error())
		}
		if errors.As(err, &storage.GroupVersionMismatchError{}) {
			return nil, status.Error(codes.InvalidArgument, err.Error())
		}
		return nil, err
	}
	return &pbresource.ReadResponse{Resource: resource}, nil
}