prometheus/discovery/zookeeper/zookeeper.go

332 lines
10 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 zookeeper
import (
"context"
"encoding/json"
"errors"
"fmt"
"net"
"strconv"
"strings"
"time"
"github.com/go-kit/log"
"github.com/go-zookeeper/zk"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/common/model"
"github.com/prometheus/prometheus/discovery"
"github.com/prometheus/prometheus/discovery/targetgroup"
"github.com/prometheus/prometheus/util/strutil"
"github.com/prometheus/prometheus/util/treecache"
)
var (
// DefaultServersetSDConfig is the default Serverset SD configuration.
DefaultServersetSDConfig = ServersetSDConfig{
Timeout: model.Duration(10 * time.Second),
}
// DefaultNerveSDConfig is the default Nerve SD configuration.
DefaultNerveSDConfig = NerveSDConfig{
Timeout: model.Duration(10 * time.Second),
}
)
func init() {
discovery.RegisterConfig(&ServersetSDConfig{})
discovery.RegisterConfig(&NerveSDConfig{})
}
// ServersetSDConfig is the configuration for Twitter serversets in Zookeeper based discovery.
type ServersetSDConfig struct {
Servers []string `yaml:"servers"`
Paths []string `yaml:"paths"`
Timeout model.Duration `yaml:"timeout,omitempty"`
}
// NewDiscovererMetrics implements discovery.Config.
func (*ServersetSDConfig) NewDiscovererMetrics(reg prometheus.Registerer, rmi discovery.RefreshMetricsInstantiator) discovery.DiscovererMetrics {
return &discovery.NoopDiscovererMetrics{}
}
// Name returns the name of the Config.
func (*ServersetSDConfig) Name() string { return "serverset" }
// NewDiscoverer returns a Discoverer for the Config.
func (c *ServersetSDConfig) NewDiscoverer(opts discovery.DiscovererOptions) (discovery.Discoverer, error) {
return NewServersetDiscovery(c, opts.Logger)
}
// UnmarshalYAML implements the yaml.Unmarshaler interface.
func (c *ServersetSDConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
*c = DefaultServersetSDConfig
type plain ServersetSDConfig
err := unmarshal((*plain)(c))
if err != nil {
return err
}
if len(c.Servers) == 0 {
return errors.New("serverset SD config must contain at least one Zookeeper server")
}
if len(c.Paths) == 0 {
return errors.New("serverset SD config must contain at least one path")
}
for _, path := range c.Paths {
if !strings.HasPrefix(path, "/") {
return fmt.Errorf("serverset SD config paths must begin with '/': %s", path)
}
}
return nil
}
// NerveSDConfig is the configuration for AirBnB's Nerve in Zookeeper based discovery.
type NerveSDConfig struct {
Servers []string `yaml:"servers"`
Paths []string `yaml:"paths"`
Timeout model.Duration `yaml:"timeout,omitempty"`
}
// NewDiscovererMetrics implements discovery.Config.
func (*NerveSDConfig) NewDiscovererMetrics(reg prometheus.Registerer, rmi discovery.RefreshMetricsInstantiator) discovery.DiscovererMetrics {
return &discovery.NoopDiscovererMetrics{}
}
// Name returns the name of the Config.
func (*NerveSDConfig) Name() string { return "nerve" }
// NewDiscoverer returns a Discoverer for the Config.
func (c *NerveSDConfig) NewDiscoverer(opts discovery.DiscovererOptions) (discovery.Discoverer, error) {
return NewNerveDiscovery(c, opts.Logger)
}
// UnmarshalYAML implements the yaml.Unmarshaler interface.
func (c *NerveSDConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
*c = DefaultNerveSDConfig
type plain NerveSDConfig
err := unmarshal((*plain)(c))
if err != nil {
return err
}
if len(c.Servers) == 0 {
return errors.New("nerve SD config must contain at least one Zookeeper server")
}
if len(c.Paths) == 0 {
return errors.New("nerve SD config must contain at least one path")
}
for _, path := range c.Paths {
if !strings.HasPrefix(path, "/") {
return fmt.Errorf("nerve SD config paths must begin with '/': %s", path)
}
}
return nil
}
// Discovery implements the Discoverer interface for discovering
// targets from Zookeeper.
type Discovery struct {
conn *zk.Conn
sources map[string]*targetgroup.Group
updates chan treecache.ZookeeperTreeCacheEvent
pathUpdates []chan treecache.ZookeeperTreeCacheEvent
treeCaches []*treecache.ZookeeperTreeCache
parse func(data []byte, path string) (model.LabelSet, error)
logger log.Logger
}
// NewNerveDiscovery returns a new Discovery for the given Nerve config.
func NewNerveDiscovery(conf *NerveSDConfig, logger log.Logger) (*Discovery, error) {
return NewDiscovery(conf.Servers, time.Duration(conf.Timeout), conf.Paths, logger, parseNerveMember)
}
// NewServersetDiscovery returns a new Discovery for the given serverset config.
func NewServersetDiscovery(conf *ServersetSDConfig, logger log.Logger) (*Discovery, error) {
return NewDiscovery(conf.Servers, time.Duration(conf.Timeout), conf.Paths, logger, parseServersetMember)
}
// NewDiscovery returns a new discovery along Zookeeper parses with
// the given parse function.
func NewDiscovery(
srvs []string,
timeout time.Duration,
paths []string,
logger log.Logger,
pf func(data []byte, path string) (model.LabelSet, error),
) (*Discovery, error) {
if logger == nil {
logger = log.NewNopLogger()
}
conn, _, err := zk.Connect(
srvs, timeout,
func(c *zk.Conn) {
c.SetLogger(treecache.NewZookeeperLogger(logger))
})
if err != nil {
return nil, err
}
updates := make(chan treecache.ZookeeperTreeCacheEvent)
sd := &Discovery{
conn: conn,
updates: updates,
sources: map[string]*targetgroup.Group{},
parse: pf,
logger: logger,
}
for _, path := range paths {
pathUpdate := make(chan treecache.ZookeeperTreeCacheEvent)
sd.pathUpdates = append(sd.pathUpdates, pathUpdate)
sd.treeCaches = append(sd.treeCaches, treecache.NewZookeeperTreeCache(conn, path, pathUpdate, logger))
}
return sd, nil
}
// Run implements the Discoverer interface.
func (d *Discovery) Run(ctx context.Context, ch chan<- []*targetgroup.Group) {
defer func() {
for _, tc := range d.treeCaches {
tc.Stop()
}
for _, pathUpdate := range d.pathUpdates {
// Drain event channel in case the treecache leaks goroutines otherwise.
for range pathUpdate {
}
}
d.conn.Close()
}()
for _, pathUpdate := range d.pathUpdates {
go func(update chan treecache.ZookeeperTreeCacheEvent) {
for event := range update {
select {
case d.updates <- event:
case <-ctx.Done():
return
}
}
}(pathUpdate)
}
for {
select {
case <-ctx.Done():
return
case event := <-d.updates:
tg := &targetgroup.Group{
Source: event.Path,
}
if event.Data != nil {
labelSet, err := d.parse(*event.Data, event.Path)
if err == nil {
tg.Targets = []model.LabelSet{labelSet}
d.sources[event.Path] = tg
} else {
delete(d.sources, event.Path)
}
} else {
delete(d.sources, event.Path)
}
select {
case <-ctx.Done():
return
case ch <- []*targetgroup.Group{tg}:
}
}
}
}
const (
serversetLabelPrefix = model.MetaLabelPrefix + "serverset_"
serversetStatusLabel = serversetLabelPrefix + "status"
serversetPathLabel = serversetLabelPrefix + "path"
serversetEndpointLabelPrefix = serversetLabelPrefix + "endpoint"
serversetShardLabel = serversetLabelPrefix + "shard"
)
type serversetMember struct {
ServiceEndpoint serversetEndpoint
AdditionalEndpoints map[string]serversetEndpoint
Status string `json:"status"`
Shard int `json:"shard"`
}
type serversetEndpoint struct {
Host string
Port int
}
func parseServersetMember(data []byte, path string) (model.LabelSet, error) {
member := serversetMember{}
if err := json.Unmarshal(data, &member); err != nil {
return nil, fmt.Errorf("error unmarshaling serverset member %q: %w", path, err)
}
labels := model.LabelSet{}
labels[serversetPathLabel] = model.LabelValue(path)
labels[model.AddressLabel] = model.LabelValue(
net.JoinHostPort(member.ServiceEndpoint.Host, fmt.Sprintf("%d", member.ServiceEndpoint.Port)))
labels[serversetEndpointLabelPrefix+"_host"] = model.LabelValue(member.ServiceEndpoint.Host)
labels[serversetEndpointLabelPrefix+"_port"] = model.LabelValue(fmt.Sprintf("%d", member.ServiceEndpoint.Port))
for name, endpoint := range member.AdditionalEndpoints {
cleanName := model.LabelName(strutil.SanitizeLabelName(name))
labels[serversetEndpointLabelPrefix+"_host_"+cleanName] = model.LabelValue(
endpoint.Host)
labels[serversetEndpointLabelPrefix+"_port_"+cleanName] = model.LabelValue(
fmt.Sprintf("%d", endpoint.Port))
}
labels[serversetStatusLabel] = model.LabelValue(member.Status)
labels[serversetShardLabel] = model.LabelValue(strconv.Itoa(member.Shard))
return labels, nil
}
const (
nerveLabelPrefix = model.MetaLabelPrefix + "nerve_"
nervePathLabel = nerveLabelPrefix + "path"
nerveEndpointLabelPrefix = nerveLabelPrefix + "endpoint"
)
type nerveMember struct {
Host string `json:"host"`
Port int `json:"port"`
Name string `json:"name"`
}
func parseNerveMember(data []byte, path string) (model.LabelSet, error) {
member := nerveMember{}
err := json.Unmarshal(data, &member)
if err != nil {
return nil, fmt.Errorf("error unmarshaling nerve member %q: %w", path, err)
}
labels := model.LabelSet{}
labels[nervePathLabel] = model.LabelValue(path)
labels[model.AddressLabel] = model.LabelValue(
net.JoinHostPort(member.Host, fmt.Sprintf("%d", member.Port)))
labels[nerveEndpointLabelPrefix+"_host"] = model.LabelValue(member.Host)
labels[nerveEndpointLabelPrefix+"_port"] = model.LabelValue(fmt.Sprintf("%d", member.Port))
labels[nerveEndpointLabelPrefix+"_name"] = model.LabelValue(member.Name)
return labels, nil
}