github.com/kaisenlinux/docker@v0.0.0-20230510090727-ea55db55fac7/swarmkit/manager/health/health.go (about)

     1  // Package health provides some utility functions to health-check a server. The implementation
     2  // is based on protobuf. Users need to write their own implementations if other IDLs are used.
     3  //
     4  // See original source: https://github.com/grpc/grpc-go/blob/master/health/health.go
     5  //
     6  // We use our own implementation of grpc server health check to include the authorization
     7  // wrapper necessary for the Managers.
     8  package health
     9  
    10  import (
    11  	"context"
    12  	"sync"
    13  
    14  	"github.com/docker/swarmkit/api"
    15  	"google.golang.org/grpc/codes"
    16  	"google.golang.org/grpc/status"
    17  )
    18  
    19  // Server represents a Health Check server to check
    20  // if a service is running or not on some host.
    21  type Server struct {
    22  	mu sync.Mutex
    23  	// statusMap stores the serving status of the services this HealthServer monitors.
    24  	statusMap map[string]api.HealthCheckResponse_ServingStatus
    25  }
    26  
    27  // NewHealthServer creates a new health check server for grpc services.
    28  func NewHealthServer() *Server {
    29  	return &Server{
    30  		statusMap: make(map[string]api.HealthCheckResponse_ServingStatus),
    31  	}
    32  }
    33  
    34  // Check checks if the grpc server is healthy and running.
    35  func (s *Server) Check(ctx context.Context, in *api.HealthCheckRequest) (*api.HealthCheckResponse, error) {
    36  	s.mu.Lock()
    37  	defer s.mu.Unlock()
    38  	if in.Service == "" {
    39  		// check the server overall health status.
    40  		return &api.HealthCheckResponse{
    41  			Status: api.HealthCheckResponse_SERVING,
    42  		}, nil
    43  	}
    44  	if status, ok := s.statusMap[in.Service]; ok {
    45  		return &api.HealthCheckResponse{
    46  			Status: status,
    47  		}, nil
    48  	}
    49  	return nil, status.Errorf(codes.NotFound, "unknown service")
    50  }
    51  
    52  // SetServingStatus is called when need to reset the serving status of a service
    53  // or insert a new service entry into the statusMap.
    54  func (s *Server) SetServingStatus(service string, status api.HealthCheckResponse_ServingStatus) {
    55  	s.mu.Lock()
    56  	s.statusMap[service] = status
    57  	s.mu.Unlock()
    58  }