prometheus/discovery/triton/triton.go

290 lines
9.0 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"
"errors"
"fmt"
"io"
"net/http"
"net/url"
"strings"
"time"
"github.com/go-kit/log"
"github.com/mwitkow/go-conntrack"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/common/config"
"github.com/prometheus/common/model"
"github.com/prometheus/prometheus/discovery"
"github.com/prometheus/prometheus/discovery/refresh"
"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"
)
// DefaultSDConfig is the default Triton SD configuration.
var DefaultSDConfig = SDConfig{
Role: "container",
Port: 9163,
RefreshInterval: model.Duration(60 * time.Second),
Version: 1,
}
func init() {
discovery.RegisterConfig(&SDConfig{})
}
// SDConfig is the configuration for Triton based service discovery.
type SDConfig struct {
Account string `yaml:"account"`
Role string `yaml:"role"`
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.TLSConfig `yaml:"tls_config,omitempty"`
Version int `yaml:"version"`
}
// Name returns the name of the Config.
func (*SDConfig) Name() string { return "triton" }
// NewDiscoverer returns a Discoverer for the Config.
func (c *SDConfig) NewDiscoverer(opts discovery.DiscovererOptions) (discovery.Discoverer, error) {
return New(opts.Logger, c, opts.Registerer)
}
// SetDirectory joins any relative file paths with dir.
func (c *SDConfig) SetDirectory(dir string) {
c.TLSConfig.SetDirectory(dir)
}
// 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.Role != "container" && c.Role != "cn" {
return errors.New("triton SD configuration requires role to be 'container' or 'cn'")
}
if c.Account == "" {
return errors.New("triton SD configuration requires an account")
}
if c.DNSSuffix == "" {
return errors.New("triton SD configuration requires a dns_suffix")
}
if c.Endpoint == "" {
return errors.New("triton SD configuration requires an endpoint")
}
if c.RefreshInterval <= 0 {
return errors.New("triton SD configuration requires RefreshInterval to be a positive integer")
}
return nil
}
// 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"`
}
// ComputeNodeDiscoveryResponse models a JSON response from the Triton discovery /gz/ endpoint.
type ComputeNodeDiscoveryResponse struct {
ComputeNodes []struct {
ServerUUID string `json:"server_uuid"`
ServerHostname string `json:"server_hostname"`
} `json:"cns"`
}
// Discovery periodically performs Triton-SD requests. It implements
// the Discoverer interface.
type Discovery struct {
*refresh.Discovery
client *http.Client
interval time.Duration
sdConfig *SDConfig
}
// New returns a new Discovery which periodically refreshes its targets.
func New(logger log.Logger, conf *SDConfig, reg prometheus.Registerer) (*Discovery, error) {
tls, err := config.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}
d := &Discovery{
client: client,
interval: time.Duration(conf.RefreshInterval),
sdConfig: conf,
}
d.Discovery = refresh.NewDiscovery(
refresh.Options{
Logger: logger,
Mech: "triton",
Interval: time.Duration(conf.RefreshInterval),
RefreshF: d.refresh,
Registry: reg,
},
)
return d, nil
}
// triton-cmon has two discovery endpoints:
// https://github.com/joyent/triton-cmon/blob/master/lib/endpoints/discover.js
//
// The default endpoint exposes "containers", otherwise called "virtual machines" in triton,
// which are (branded) zones running on the triton platform.
//
// The /gz/ endpoint exposes "compute nodes", also known as "servers" or "global zones",
// on which the "containers" are running.
//
// As triton is not internally consistent in using these names,
// the terms as used in triton-cmon are used here.
func (d *Discovery) refresh(ctx context.Context) ([]*targetgroup.Group, error) {
var endpointFormat string
switch d.sdConfig.Role {
case "container":
endpointFormat = "https://%s:%d/v%d/discover"
case "cn":
endpointFormat = "https://%s:%d/v%d/gz/discover"
default:
return nil, fmt.Errorf("unknown role '%s' in configuration", d.sdConfig.Role)
}
endpoint := fmt.Sprintf(endpointFormat, 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)
}
req, err := http.NewRequest("GET", endpoint, nil)
if err != nil {
return nil, err
}
req = req.WithContext(ctx)
resp, err := d.client.Do(req)
if err != nil {
return nil, fmt.Errorf("an error occurred when requesting targets from the discovery endpoint: %w", err)
}
defer func() {
io.Copy(io.Discard, resp.Body)
resp.Body.Close()
}()
data, err := io.ReadAll(resp.Body)
if err != nil {
return nil, fmt.Errorf("an error occurred when reading the response body: %w", err)
}
// The JSON response body is different so it needs to be processed/mapped separately.
switch d.sdConfig.Role {
case "container":
return d.processContainerResponse(data, endpoint)
case "cn":
return d.processComputeNodeResponse(data, endpoint)
default:
return nil, fmt.Errorf("unknown role '%s' in configuration", d.sdConfig.Role)
}
}
func (d *Discovery) processContainerResponse(data []byte, endpoint string) ([]*targetgroup.Group, error) {
tg := &targetgroup.Group{
Source: endpoint,
}
dr := DiscoveryResponse{}
err := json.Unmarshal(data, &dr)
if err != nil {
return nil, fmt.Errorf("an error occurred unmarshaling the discovery response json: %w", 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 []*targetgroup.Group{tg}, nil
}
func (d *Discovery) processComputeNodeResponse(data []byte, endpoint string) ([]*targetgroup.Group, error) {
tg := &targetgroup.Group{
Source: endpoint,
}
dr := ComputeNodeDiscoveryResponse{}
err := json.Unmarshal(data, &dr)
if err != nil {
return nil, fmt.Errorf("an error occurred unmarshaling the compute node discovery response json: %w", err)
}
for _, cn := range dr.ComputeNodes {
labels := model.LabelSet{
tritonLabelMachineID: model.LabelValue(cn.ServerUUID),
tritonLabelMachineAlias: model.LabelValue(cn.ServerHostname),
}
addr := fmt.Sprintf("%s.%s:%d", cn.ServerUUID, d.sdConfig.DNSSuffix, d.sdConfig.Port)
labels[model.AddressLabel] = model.LabelValue(addr)
tg.Targets = append(tg.Targets, labels)
}
return []*targetgroup.Group{tg}, nil
}