prometheus/retrieval/discovery/ec2.go

155 lines
4.4 KiB
Go

// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package discovery
import (
"fmt"
"strings"
"time"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/credentials"
"github.com/aws/aws-sdk-go/aws/defaults"
"github.com/prometheus/common/log"
"github.com/prometheus/common/model"
"golang.org/x/net/context"
"github.com/aws/aws-sdk-go/service/ec2"
"github.com/prometheus/prometheus/config"
"github.com/prometheus/prometheus/util/strutil"
)
const (
ec2Label = model.MetaLabelPrefix + "ec2_"
ec2LabelAZ = ec2Label + "availability_zone"
ec2LabelInstanceID = ec2Label + "instance_id"
ec2LabelPublicDNS = ec2Label + "public_dns_name"
ec2LabelPublicIP = ec2Label + "public_ip"
ec2LabelPrivateIP = ec2Label + "private_ip"
ec2LabelSubnetID = ec2Label + "subnet_id"
ec2LabelTag = ec2Label + "tag_"
ec2LabelVPCID = ec2Label + "vpc_id"
subnetSeparator = ","
)
// EC2Discovery periodically performs EC2-SD requests. It implements
// the TargetProvider interface.
type EC2Discovery struct {
aws *aws.Config
interval time.Duration
port int
}
// NewEC2Discovery returns a new EC2Discovery which periodically refreshes its targets.
func NewEC2Discovery(conf *config.EC2SDConfig) *EC2Discovery {
creds := credentials.NewStaticCredentials(conf.AccessKey, conf.SecretKey, "")
if conf.AccessKey == "" && conf.SecretKey == "" {
creds = defaults.DefaultChainCredentials
}
return &EC2Discovery{
aws: &aws.Config{
Region: &conf.Region,
Credentials: creds,
},
interval: time.Duration(conf.RefreshInterval),
port: conf.Port,
}
}
// Run implements the TargetProvider interface.
func (ed *EC2Discovery) Run(ctx context.Context, ch chan<- []*config.TargetGroup) {
defer close(ch)
ticker := time.NewTicker(ed.interval)
defer ticker.Stop()
// Get an initial set right away.
tg, err := ed.refresh()
if err != nil {
log.Error(err)
} else {
ch <- []*config.TargetGroup{tg}
}
for {
select {
case <-ticker.C:
tg, err := ed.refresh()
if err != nil {
log.Error(err)
} else {
ch <- []*config.TargetGroup{tg}
}
case <-ctx.Done():
return
}
}
}
func (ed *EC2Discovery) refresh() (*config.TargetGroup, error) {
ec2s := ec2.New(ed.aws)
tg := &config.TargetGroup{
Source: *ed.aws.Region,
}
if err := ec2s.DescribeInstancesPages(nil, func(p *ec2.DescribeInstancesOutput, lastPage bool) bool {
for _, r := range p.Reservations {
for _, inst := range r.Instances {
if inst.PrivateIpAddress == nil {
continue
}
labels := model.LabelSet{
ec2LabelInstanceID: model.LabelValue(*inst.InstanceId),
}
labels[ec2LabelPrivateIP] = model.LabelValue(*inst.PrivateIpAddress)
addr := fmt.Sprintf("%s:%d", *inst.PrivateIpAddress, ed.port)
labels[model.AddressLabel] = model.LabelValue(addr)
if inst.PublicIpAddress != nil {
labels[ec2LabelPublicIP] = model.LabelValue(*inst.PublicIpAddress)
labels[ec2LabelPublicDNS] = model.LabelValue(*inst.PublicDnsName)
}
labels[ec2LabelAZ] = model.LabelValue(*inst.Placement.AvailabilityZone)
if inst.VpcId != nil {
labels[ec2LabelVPCID] = model.LabelValue(*inst.VpcId)
subnetsMap := make(map[string]struct{})
for _, eni := range inst.NetworkInterfaces {
subnetsMap[*eni.SubnetId] = struct{}{}
}
subnets := []string{}
for k := range subnetsMap {
subnets = append(subnets, k)
}
labels[ec2LabelSubnetID] = model.LabelValue(
subnetSeparator +
strings.Join(subnets, subnetSeparator) +
subnetSeparator)
}
for _, t := range inst.Tags {
name := strutil.SanitizeLabelName(*t.Key)
labels[ec2LabelTag+model.LabelName(name)] = model.LabelValue(*t.Value)
}
tg.Targets = append(tg.Targets, labels)
}
}
return true
}); err != nil {
return nil, fmt.Errorf("could not describe instances: %s", err)
}
return tg, nil
}