*: avoid missed Alertmanager targets (#6455)

This change makes sure that nearly-identical Alertmanager configurations
aren't merged together.

The config's identifier was the MD5 hash of the configuration serialized
to JSON but because `relabel.Regexp` has no public field and doesn't
implement the JSON.Marshaler interface, it was always serialized to
"{}".

In practice, the identifier can be based on the index of the
configuration in the list.

Signed-off-by: Simon Pasquier <spasquie@redhat.com>
This commit is contained in:
Simon Pasquier 2019-12-12 17:00:19 +01:00 committed by GitHub
parent 48d25e6fe7
commit cccd542891
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
4 changed files with 38 additions and 43 deletions

View file

@ -16,8 +16,6 @@ package main
import (
"context"
"crypto/md5"
"encoding/json"
"fmt"
"net"
"net/http"
@ -435,13 +433,8 @@ func main() {
notifierManager.ApplyConfig,
func(cfg *config.Config) error {
c := make(map[string]sd_config.ServiceDiscoveryConfig)
for _, v := range cfg.AlertingConfig.AlertmanagerConfigs {
// AlertmanagerConfigs doesn't hold an unique identifier so we use the config hash as the identifier.
b, err := json.Marshal(v)
if err != nil {
return err
}
c[fmt.Sprintf("%x", md5.Sum(b))] = v.ServiceDiscoveryConfig
for k, v := range cfg.AlertingConfig.AlertmanagerConfigs.ToMap() {
c[k] = v.ServiceDiscoveryConfig
}
return discoveryManagerNotify.ApplyConfig(c)
},

View file

@ -433,7 +433,7 @@ func (c *ScrapeConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
// AlertingConfig configures alerting and alertmanager related configs.
type AlertingConfig struct {
AlertRelabelConfigs []*relabel.Config `yaml:"alert_relabel_configs,omitempty"`
AlertmanagerConfigs []*AlertmanagerConfig `yaml:"alertmanagers,omitempty"`
AlertmanagerConfigs AlertmanagerConfigs `yaml:"alertmanagers,omitempty"`
}
// UnmarshalYAML implements the yaml.Unmarshaler interface.
@ -454,6 +454,18 @@ func (c *AlertingConfig) UnmarshalYAML(unmarshal func(interface{}) error) error
return nil
}
// AlertmanagerConfigs is a slice of *AlertmanagerConfig.
type AlertmanagerConfigs []*AlertmanagerConfig
// ToMap converts a slice of *AlertmanagerConfig to a map.
func (a AlertmanagerConfigs) ToMap() map[string]*AlertmanagerConfig {
ret := make(map[string]*AlertmanagerConfig)
for i := range a {
ret[fmt.Sprintf("config-%d", i)] = a[i]
}
return ret
}
// AlertmanagerAPIVersion represents a version of the
// github.com/prometheus/alertmanager/api, e.g. 'v1' or 'v2'.
type AlertmanagerAPIVersion string

View file

@ -16,7 +16,6 @@ package notifier
import (
"bytes"
"context"
"crypto/md5"
"encoding/json"
"fmt"
"io"
@ -262,20 +261,13 @@ func (n *Manager) ApplyConfig(conf *config.Config) error {
amSets := make(map[string]*alertmanagerSet)
for _, cfg := range conf.AlertingConfig.AlertmanagerConfigs {
ams, err := newAlertmanagerSet(cfg, n.logger)
for k, cfg := range conf.AlertingConfig.AlertmanagerConfigs.ToMap() {
ams, err := newAlertmanagerSet(cfg, n.logger, n.metrics)
if err != nil {
return err
}
ams.metrics = n.metrics
// The config hash is used for the map lookup identifier.
b, err := json.Marshal(cfg)
if err != nil {
return err
}
amSets[fmt.Sprintf("%x", md5.Sum(b))] = ams
amSets[k] = ams
}
n.alertmanagers = amSets
@ -638,7 +630,7 @@ type alertmanagerSet struct {
logger log.Logger
}
func newAlertmanagerSet(cfg *config.AlertmanagerConfig, logger log.Logger) (*alertmanagerSet, error) {
func newAlertmanagerSet(cfg *config.AlertmanagerConfig, logger log.Logger, metrics *alertMetrics) (*alertmanagerSet, error) {
client, err := config_util.NewClientFromConfig(cfg.HTTPClientConfig, "alertmanager", false)
if err != nil {
return nil, err
@ -647,6 +639,7 @@ func newAlertmanagerSet(cfg *config.AlertmanagerConfig, logger log.Logger) (*ale
client: client,
cfg: cfg,
logger: logger,
metrics: metrics,
}
return s, nil
}

View file

@ -16,7 +16,6 @@ package notifier
import (
"bytes"
"context"
"crypto/md5"
"encoding/json"
"fmt"
"io/ioutil"
@ -467,6 +466,7 @@ alerting:
if err := yaml.UnmarshalStrict([]byte(s), cfg); err != nil {
t.Fatalf("Unable to load YAML config: %s", err)
}
testutil.Equals(t, 1, len(cfg.AlertingConfig.AlertmanagerConfigs))
if err := n.ApplyConfig(cfg); err != nil {
t.Fatalf("Error Applying the config:%v", err)
@ -474,18 +474,16 @@ alerting:
tgs := make(map[string][]*targetgroup.Group)
for _, tt := range tests {
b, err := json.Marshal(cfg.AlertingConfig.AlertmanagerConfigs[0])
if err != nil {
t.Fatalf("Error creating config hash:%v", err)
}
tgs[fmt.Sprintf("%x", md5.Sum(b))] = []*targetgroup.Group{
for k := range cfg.AlertingConfig.AlertmanagerConfigs.ToMap() {
tgs[k] = []*targetgroup.Group{
tt.in,
}
break
}
n.reload(tgs)
res := n.Alertmanagers()[0].String()
testutil.Equals(t, res, tt.out)
testutil.Equals(t, tt.out, res)
}
}
@ -522,6 +520,7 @@ alerting:
if err := yaml.UnmarshalStrict([]byte(s), cfg); err != nil {
t.Fatalf("Unable to load YAML config: %s", err)
}
testutil.Equals(t, 1, len(cfg.AlertingConfig.AlertmanagerConfigs))
if err := n.ApplyConfig(cfg); err != nil {
t.Fatalf("Error Applying the config:%v", err)
@ -529,20 +528,18 @@ alerting:
tgs := make(map[string][]*targetgroup.Group)
for _, tt := range tests {
b, err := json.Marshal(cfg.AlertingConfig.AlertmanagerConfigs[0])
if err != nil {
t.Fatalf("Error creating config hash:%v", err)
}
tgs[fmt.Sprintf("%x", md5.Sum(b))] = []*targetgroup.Group{
for k := range cfg.AlertingConfig.AlertmanagerConfigs.ToMap() {
tgs[k] = []*targetgroup.Group{
tt.in,
}
break
}
n.reload(tgs)
res := n.DroppedAlertmanagers()[0].String()
testutil.Equals(t, res, tt.out)
}
}
func makeInputTargetGroup() *targetgroup.Group {