open-nomad/nomad/client_stats_endpoint.go
2018-02-15 13:59:00 -08:00

94 lines
2.1 KiB
Go

package nomad
import (
"errors"
"fmt"
"strings"
"time"
metrics "github.com/armon/go-metrics"
msgpackrpc "github.com/hashicorp/net-rpc-msgpackrpc"
"github.com/hashicorp/nomad/client/structs"
nstructs "github.com/hashicorp/nomad/nomad/structs"
)
// TODO(alexdadgar): move to errors.go
const (
errNoNodeConn = "No path to node"
)
var (
ErrNoNodeConn = errors.New(errNoNodeConn)
)
func IsErrNoNodeConn(err error) bool {
return err != nil && strings.Contains(err.Error(), errNoNodeConn)
}
// ClientStats is used to forward RPC requests to the targed Nomad client's
// ClientStats endpoint.
type ClientStats struct {
srv *Server
}
func (s *ClientStats) Stats(args *structs.ClientStatsRequest, reply *structs.ClientStatsResponse) error {
// We only allow stale reads since the only potentially stale information is
// the Node registration and the cost is fairly high for adding another hope
// in the forwarding chain.
args.QueryOptions.AllowStale = true
// Potentially forward to a different region.
if done, err := s.srv.forward("ClientStats.Stats", args, args, reply); done {
return err
}
defer metrics.MeasureSince([]string{"nomad", "client_stats", "stats"}, time.Now())
// Check node read permissions
if aclObj, err := s.srv.ResolveToken(args.AuthToken); err != nil {
return err
} else if aclObj != nil && !aclObj.AllowNodeRead() {
return nstructs.ErrPermissionDenied
}
// Verify the arguments.
if args.NodeID == "" {
return errors.New("missing NodeID")
}
// Get the connection to the client
session, ok := s.srv.getNodeConn(args.NodeID)
if !ok {
// Check if the node even exists
snap, err := s.srv.State().Snapshot()
if err != nil {
return err
}
node, err := snap.NodeByID(nil, args.NodeID)
if err != nil {
return err
}
if node == nil {
return fmt.Errorf("Unknown node %q", args.NodeID)
}
// TODO Handle forwarding to other servers
return ErrNoNodeConn
}
// Open a new session
stream, err := session.Open()
if err != nil {
return err
}
// Make the RPC
err = msgpackrpc.CallWithCodec(NewClientCodec(stream), "ClientStats.Stats", args, reply)
if err != nil {
return err
}
return nil
}