github.com/fafucoder/cilium@v1.6.11/pkg/monitor/agent/listener1_2.go (about)

     1  // Copyright 2018-2019 Authors of Cilium
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package agent
    16  
    17  import (
    18  	"encoding/gob"
    19  	"net"
    20  
    21  	"github.com/cilium/cilium/pkg/monitor/agent/listener"
    22  	"github.com/cilium/cilium/pkg/monitor/payload"
    23  )
    24  
    25  // listenerv1_2 implements the ciliim-node-monitor API protocol compatible with
    26  // cilium 1.2
    27  // cleanupFn is called on exit
    28  type listenerv1_2 struct {
    29  	conn      net.Conn
    30  	queue     chan *payload.Payload
    31  	cleanupFn func(listener.MonitorListener)
    32  }
    33  
    34  func newListenerv1_2(c net.Conn, queueSize int, cleanupFn func(listener.MonitorListener)) *listenerv1_2 {
    35  	ml := &listenerv1_2{
    36  		conn:      c,
    37  		queue:     make(chan *payload.Payload, queueSize),
    38  		cleanupFn: cleanupFn,
    39  	}
    40  
    41  	go ml.drainQueue()
    42  
    43  	return ml
    44  }
    45  
    46  func (ml *listenerv1_2) Enqueue(pl *payload.Payload) {
    47  	select {
    48  	case ml.queue <- pl:
    49  	default:
    50  		log.Debug("Per listener queue is full, dropping message")
    51  	}
    52  }
    53  
    54  // drainQueue encodes and sends monitor payloads to the listener. It is
    55  // intended to be a goroutine.
    56  func (ml *listenerv1_2) drainQueue() {
    57  	defer func() {
    58  		ml.conn.Close()
    59  		ml.cleanupFn(ml)
    60  	}()
    61  
    62  	enc := gob.NewEncoder(ml.conn)
    63  	for pl := range ml.queue {
    64  		if err := pl.EncodeBinary(enc); err != nil {
    65  			switch {
    66  			case listener.IsDisconnected(err):
    67  				log.Debug("Listener disconnected")
    68  				return
    69  
    70  			default:
    71  				log.WithError(err).Warn("Removing listener due to write failure")
    72  				return
    73  			}
    74  		}
    75  	}
    76  }
    77  
    78  func (ml *listenerv1_2) Version() listener.Version {
    79  	return listener.Version1_2
    80  }