prometheus/discovery/triton/triton.go

243 lines
7.0 KiB
Go

// Copyright 2017 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 triton
import (
"context"
"encoding/json"
"fmt"
"io/ioutil"
"net/http"
"net/url"
"strings"
"time"
"github.com/go-kit/kit/log"
"github.com/go-kit/kit/log/level"
"github.com/mwitkow/go-conntrack"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/common/model"
config_util "github.com/prometheus/common/config"
"github.com/prometheus/prometheus/discovery/targetgroup"
)
const (
tritonLabel = model.MetaLabelPrefix + "triton_"
tritonLabelGroups = tritonLabel + "groups"
tritonLabelMachineID = tritonLabel + "machine_id"
tritonLabelMachineAlias = tritonLabel + "machine_alias"
tritonLabelMachineBrand = tritonLabel + "machine_brand"
tritonLabelMachineImage = tritonLabel + "machine_image"
tritonLabelServerID = tritonLabel + "server_id"
namespace = "prometheus"
)
var (
refreshFailuresCount = prometheus.NewCounter(
prometheus.CounterOpts{
Name: "prometheus_sd_triton_refresh_failures_total",
Help: "The number of Triton-SD scrape failures.",
})
refreshDuration = prometheus.NewSummary(
prometheus.SummaryOpts{
Name: "prometheus_sd_triton_refresh_duration_seconds",
Help: "The duration of a Triton-SD refresh in seconds.",
})
// DefaultSDConfig is the default Triton SD configuration.
DefaultSDConfig = SDConfig{
Port: 9163,
RefreshInterval: model.Duration(60 * time.Second),
Version: 1,
}
)
// SDConfig is the configuration for Triton based service discovery.
type SDConfig struct {
Account string `yaml:"account"`
DNSSuffix string `yaml:"dns_suffix"`
Endpoint string `yaml:"endpoint"`
Groups []string `yaml:"groups,omitempty"`
Port int `yaml:"port"`
RefreshInterval model.Duration `yaml:"refresh_interval,omitempty"`
TLSConfig config_util.TLSConfig `yaml:"tls_config,omitempty"`
Version int `yaml:"version"`
}
// UnmarshalYAML implements the yaml.Unmarshaler interface.
func (c *SDConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
*c = DefaultSDConfig
type plain SDConfig
err := unmarshal((*plain)(c))
if err != nil {
return err
}
if c.Account == "" {
return fmt.Errorf("Triton SD configuration requires an account")
}
if c.DNSSuffix == "" {
return fmt.Errorf("Triton SD configuration requires a dns_suffix")
}
if c.Endpoint == "" {
return fmt.Errorf("Triton SD configuration requires an endpoint")
}
if c.RefreshInterval <= 0 {
return fmt.Errorf("Triton SD configuration requires RefreshInterval to be a positive integer")
}
return nil
}
func init() {
prometheus.MustRegister(refreshFailuresCount)
prometheus.MustRegister(refreshDuration)
}
// DiscoveryResponse models a JSON response from the Triton discovery.
type DiscoveryResponse struct {
Containers []struct {
Groups []string `json:"groups"`
ServerUUID string `json:"server_uuid"`
VMAlias string `json:"vm_alias"`
VMBrand string `json:"vm_brand"`
VMImageUUID string `json:"vm_image_uuid"`
VMUUID string `json:"vm_uuid"`
} `json:"containers"`
}
// Discovery periodically performs Triton-SD requests. It implements
// the Discoverer interface.
type Discovery struct {
client *http.Client
interval time.Duration
logger log.Logger
sdConfig *SDConfig
}
// New returns a new Discovery which periodically refreshes its targets.
func New(logger log.Logger, conf *SDConfig) (*Discovery, error) {
if logger == nil {
logger = log.NewNopLogger()
}
tls, err := config_util.NewTLSConfig(&conf.TLSConfig)
if err != nil {
return nil, err
}
transport := &http.Transport{
TLSClientConfig: tls,
DialContext: conntrack.NewDialContextFunc(
conntrack.DialWithTracing(),
conntrack.DialWithName("triton_sd"),
),
}
client := &http.Client{Transport: transport}
return &Discovery{
client: client,
interval: time.Duration(conf.RefreshInterval),
logger: logger,
sdConfig: conf,
}, nil
}
// Run implements the Discoverer interface.
func (d *Discovery) Run(ctx context.Context, ch chan<- []*targetgroup.Group) {
defer close(ch)
ticker := time.NewTicker(d.interval)
defer ticker.Stop()
// Get an initial set right away.
tg, err := d.refresh()
if err != nil {
level.Error(d.logger).Log("msg", "Refreshing targets failed", "err", err)
} else {
ch <- []*targetgroup.Group{tg}
}
for {
select {
case <-ticker.C:
tg, err := d.refresh()
if err != nil {
level.Error(d.logger).Log("msg", "Refreshing targets failed", "err", err)
} else {
ch <- []*targetgroup.Group{tg}
}
case <-ctx.Done():
return
}
}
}
func (d *Discovery) refresh() (tg *targetgroup.Group, err error) {
t0 := time.Now()
defer func() {
refreshDuration.Observe(time.Since(t0).Seconds())
if err != nil {
refreshFailuresCount.Inc()
}
}()
var endpoint = fmt.Sprintf("https://%s:%d/v%d/discover", d.sdConfig.Endpoint, d.sdConfig.Port, d.sdConfig.Version)
if len(d.sdConfig.Groups) > 0 {
groups := url.QueryEscape(strings.Join(d.sdConfig.Groups, ","))
endpoint = fmt.Sprintf("%s?groups=%s", endpoint, groups)
}
tg = &targetgroup.Group{
Source: endpoint,
}
resp, err := d.client.Get(endpoint)
if err != nil {
return tg, fmt.Errorf("an error occurred when requesting targets from the discovery endpoint. %s", err)
}
defer resp.Body.Close()
data, err := ioutil.ReadAll(resp.Body)
if err != nil {
return tg, fmt.Errorf("an error occurred when reading the response body. %s", err)
}
dr := DiscoveryResponse{}
err = json.Unmarshal(data, &dr)
if err != nil {
return tg, fmt.Errorf("an error occurred unmarshaling the disovery response json. %s", err)
}
for _, container := range dr.Containers {
labels := model.LabelSet{
tritonLabelMachineID: model.LabelValue(container.VMUUID),
tritonLabelMachineAlias: model.LabelValue(container.VMAlias),
tritonLabelMachineBrand: model.LabelValue(container.VMBrand),
tritonLabelMachineImage: model.LabelValue(container.VMImageUUID),
tritonLabelServerID: model.LabelValue(container.ServerUUID),
}
addr := fmt.Sprintf("%s.%s:%d", container.VMUUID, d.sdConfig.DNSSuffix, d.sdConfig.Port)
labels[model.AddressLabel] = model.LabelValue(addr)
if len(container.Groups) > 0 {
name := "," + strings.Join(container.Groups, ",") + ","
labels[tritonLabelGroups] = model.LabelValue(name)
}
tg.Targets = append(tg.Targets, labels)
}
return tg, nil
}