channel_test.go

Documentation: github.com/prometheus/alertmanager/cluster

     1  // Copyright 2018 Prometheus Team
     2  // Licensed under the Apache License, Version 2.0 (the "License");
     3  // you may not use this file except in compliance with the License.
     4  // You may obtain a copy of the License at
     5  //
     6  // http://www.apache.org/licenses/LICENSE-2.0
     7  //
     8  // Unless required by applicable law or agreed to in writing, software
     9  // distributed under the License is distributed on an "AS IS" BASIS,
    10  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package cluster
    15  
    16  import (
    17  	"bytes"
    18  	"context"
    19  	"io"
    20  	"os"
    21  	"testing"
    22  
    23  	"github.com/go-kit/log"
    24  	"github.com/hashicorp/memberlist"
    25  	"github.com/prometheus/client_golang/prometheus"
    26  )
    27  
    28  func TestNormalMessagesGossiped(t *testing.T) {
    29  	var sent bool
    30  	c := newChannel(
    31  		func(_ []byte) { sent = true },
    32  		func() []*memberlist.Node { return nil },
    33  		func(_ *memberlist.Node, _ []byte) error { return nil },
    34  	)
    35  
    36  	c.Broadcast([]byte{})
    37  
    38  	if sent != true {
    39  		t.Fatalf("small message not sent")
    40  	}
    41  }
    42  
    43  func TestOversizedMessagesGossiped(t *testing.T) {
    44  	var sent bool
    45  	ctx, cancel := context.WithCancel(context.Background())
    46  	c := newChannel(
    47  		func(_ []byte) {},
    48  		func() []*memberlist.Node { return []*memberlist.Node{{}} },
    49  		func(_ *memberlist.Node, _ []byte) error { sent = true; cancel(); return nil },
    50  	)
    51  
    52  	f, err := os.Open("/dev/zero")
    53  	if err != nil {
    54  		t.Fatalf("failed to open /dev/zero: %v", err)
    55  	}
    56  	defer f.Close()
    57  
    58  	buf := new(bytes.Buffer)
    59  	toCopy := int64(800)
    60  	if n, err := io.CopyN(buf, f, toCopy); err != nil {
    61  		t.Fatalf("failed to copy bytes: %v", err)
    62  	} else if n != toCopy {
    63  		t.Fatalf("wanted to copy %d bytes, only copied %d", toCopy, n)
    64  	}
    65  
    66  	c.Broadcast(buf.Bytes())
    67  
    68  	<-ctx.Done()
    69  
    70  	if sent != true {
    71  		t.Fatalf("oversized message not sent")
    72  	}
    73  }
    74  
    75  func newChannel(
    76  	send func([]byte),
    77  	peers func() []*memberlist.Node,
    78  	sendOversize func(*memberlist.Node, []byte) error,
    79  ) *Channel {
    80  	return NewChannel(
    81  		"test",
    82  		send,
    83  		peers,
    84  		sendOversize,
    85  		log.NewNopLogger(),
    86  		make(chan struct{}),
    87  		prometheus.NewRegistry(),
    88  	)
    89  }
    90
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