VictoriaMetrics/app/vmalert/notifier/alert.go
Roman Khavronenko b099d84271
Vmalert/rules eval (#400)
* Initial rules evaluation support.

Rules are now store alerts state in private field `alerts`. Every evaluation updates
the alerts and state. Every unique metric received from datastore represents a unique alert,
uniqueness is guaranteed by hashing ordered labelset.

* merge with master

* cleanup

* support endAt parameter as 3*evaluationInterval for active alerts

* make golint happy
2020-04-06 14:44:03 +03:00

108 lines
2.7 KiB
Go

package notifier
import (
"bytes"
"fmt"
"io"
"strings"
"text/template"
"time"
)
// Alert the triggered alert
// TODO: Looks like alert name isn't unique
type Alert struct {
Group string
Name string
Labels map[string]string
Annotations map[string]string
State AlertState
Start time.Time
End time.Time
Value float64
}
// AlertState type indicates the Alert state
type AlertState int
const (
// StateInactive is the state of an alert that is neither firing nor pending.
StateInactive AlertState = iota
// StatePending is the state of an alert that has been active for less than
// the configured threshold duration.
StatePending
// StateFiring is the state of an alert that has been active for longer than
// the configured threshold duration.
StateFiring
)
type alertTplData struct {
Labels map[string]string
Value float64
}
const tplHeader = `{{ $value := .Value }}{{ $labels := .Labels }}`
// ExecTemplate executes the Alert template for give
// map of annotations.
func (a *Alert) ExecTemplate(annotations map[string]string) (map[string]string, error) {
tplData := alertTplData{Value: a.Value, Labels: a.Labels}
return templateAnnotations(annotations, tplHeader, tplData)
}
// ValidateAnnotations validate annotations for possible template error, uses empty data for template population
func ValidateAnnotations(annotations map[string]string) error {
_, err := templateAnnotations(annotations, tplHeader, alertTplData{
Labels: map[string]string{},
Value: 0,
})
return err
}
func templateAnnotations(annotations map[string]string, header string, data alertTplData) (map[string]string, error) {
var builder strings.Builder
var buf bytes.Buffer
eg := errGroup{}
r := make(map[string]string, len(annotations))
for key, text := range annotations {
r[key] = text
buf.Reset()
builder.Reset()
builder.Grow(len(header) + len(text))
builder.WriteString(header)
builder.WriteString(text)
if err := templateAnnotation(&buf, builder.String(), data); err != nil {
eg.errs = append(eg.errs, fmt.Sprintf("key %s, template %s:%s", key, text, err))
continue
}
r[key] = buf.String()
}
return r, eg.err()
}
func templateAnnotation(dst io.Writer, text string, data alertTplData) error {
tpl, err := template.New("").Funcs(tmplFunc).Option("missingkey=zero").Parse(text)
if err != nil {
return fmt.Errorf("error parsing annotation:%w", err)
}
if err = tpl.Execute(dst, data); err != nil {
return fmt.Errorf("error evaluating annotation template:%w", err)
}
return nil
}
type errGroup struct {
errs []string
}
func (eg *errGroup) err() error {
if eg == nil || len(eg.errs) == 0 {
return nil
}
return eg
}
func (eg *errGroup) Error() string {
return fmt.Sprintf("errors:%s", strings.Join(eg.errs, "\n"))
}