pkg/rulefmt: Add rule group parsing

This commit is contained in:
Fabian Reinartz 2017-06-07 16:58:15 +02:00
parent 669075c6b9
commit c843a0cd29
3 changed files with 169 additions and 0 deletions

98
pkg/rulefmt/rulefmt.go Normal file
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@ -0,0 +1,98 @@
package rulefmt
import (
"io/ioutil"
"github.com/ghodss/yaml"
"github.com/pkg/errors"
"github.com/prometheus/prometheus/promql"
)
// Error represents semantical errors on parsing rule groups.
type Error struct {
Group string
Rule int
Err error
}
func (err *Error) Error() string {
return errors.Wrapf(err, "group %q, rule %d", err.Group, err.Rule).Error()
}
// RuleGroups is a set of rule groups that are typically exposed in a file.
type RuleGroups struct {
Version int `json:"version"`
Groups []RuleGroup `json:"groups"`
}
// Validate validates all rules in the rule groups.
func (g *RuleGroups) Validate() (errs []error) {
if g.Version != 1 {
errs = append(errs, errors.Errorf("invalid rule group version %d", g.Version))
}
for _, g := range g.Groups {
for i, r := range g.Rules {
for _, err := range r.Validate() {
errs = append(errs, &Error{
Group: g.Name,
Rule: i,
Err: err,
})
}
}
}
return errs
}
// RuleGroup is a list of sequentially evaluated recording and alerting rules.
type RuleGroup struct {
Name string `json:"name"`
Rules []Rule `json:"rules"`
}
// Rule describes an alerting or recording rule.
type Rule struct {
Record string `json:"record"`
Alert string `json:"alert"`
Expr string `json:"expr"`
For string `json:"for"`
Labels map[string]string `json:"labels"`
Annotations map[string]string `json:"annotations"`
}
// Validate the rule and return a list of encountered errors.
func (r *Rule) Validate() (errs []error) {
if r.Record != "" && r.Alert != "" {
errs = append(errs, errors.Errorf("only one of 'record' and 'alert' must be set"))
}
if r.Record == "" && r.Alert == "" {
errs = append(errs, errors.Errorf("one of 'record' or 'alert' must be set"))
}
if r.Expr == "" {
errs = append(errs, errors.Errorf("field 'expr' must be set in rule"))
} else if _, err := promql.ParseExpr(r.Expr); err != nil {
errs = append(errs, errors.Errorf("could not parse expression: %s", err))
}
if r.Record != "" {
if len(r.Annotations) > 0 {
errs = append(errs, errors.Errorf("invalid field 'annotations' in recording rule"))
}
if r.For != "" {
errs = append(errs, errors.Errorf("invalid field 'for' in recording rule"))
}
}
return errs
}
// ParseFile parses the rule file and validates it.
func ParseFile(file string) (*RuleGroups, []error) {
b, err := ioutil.ReadFile(file)
if err != nil {
return nil, []error{err}
}
var groups RuleGroups
if err := yaml.Unmarshal(b, &groups); err != nil {
return nil, []error{err}
}
return &groups, groups.Validate()
}

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package rulefmt
import "testing"
func TestParseFileSuccess(t *testing.T) {
if _, errs := ParseFile("testdata/test.yaml"); len(errs) > 0 {
t.Errorf("unexpected errors parsing file")
for _, err := range errs {
t.Error(err)
}
}
}

59
pkg/rulefmt/testdata/test.yaml vendored Normal file
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version: 1
groups:
- name: my-group-name
interval: 30s # defaults to global interval
rules:
- alert: HighErrors
expr: |
sum without(instance) (rate(errors_total[5m]))
/ sum without(instance) (rate(requests_total[5m]))
for: 5m
labels:
severity: critical
annotations:
description: "stuff's happening with {{ $.labels.service }}"
# Mix recording rules in the same list
- record: "new_metric"
expr: |
sum without(instance) (rate(errors_total[5m]))
/ sum without(instance) (rate(requests_total[5m]))
labels:
abc: edf
uvw: xyz
- alert: HighErrors
expr: |
sum without(instance) (rate(errors_total[5m]))
/ sum without(instance) (rate(requests_total[5m]))
for: 5m
labels:
severity: critical
annotations:
description: "stuff's happening with {{ $.labels.service }}"
- name: my-group-name
interval: 30s # defaults to global interval
rules:
- alert: HighErrors
expr: |
sum without(instance) (rate(errors_total[5m]))
/ sum without(instance) (rate(requests_total[5m]))
for: 5m
labels:
severity: critical
- record: "new_metric"
expr: |
sum without(instance) (rate(errors_total[5m]))
/ sum without(instance) (rate(requests_total[5m]))
- alert: HighErrors
expr: |
sum without(instance) (rate(errors_total[5m]))
/ sum without(instance) (rate(requests_total[5m]))
for: 5m
labels:
severity: critical
annotations:
description: "stuff's happening with {{ $.labels.service }}"