prometheus/rules/rules.go

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// Copyright 2013 Prometheus Team
// 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 rules
import (
"fmt"
"github.com/prometheus/prometheus/model"
"github.com/prometheus/prometheus/rules/ast"
"time"
)
// A recorded rule.
type Rule struct {
name string
vector ast.VectorNode
labels model.LabelSet
permanent bool
}
func (rule *Rule) Name() string { return rule.name }
func (rule *Rule) EvalRaw(timestamp *time.Time) (vector ast.Vector, err error) {
return ast.EvalVectorInstant(rule.vector, *timestamp)
}
func (rule *Rule) Eval(timestamp *time.Time) (vector ast.Vector, err error) {
// Get the raw value of the rule expression.
vector, err = rule.EvalRaw(timestamp)
if err != nil {
return
}
// Override the metric name and labels.
for _, sample := range vector {
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sample.Metric[model.MetricNameLabel] = model.LabelValue(rule.name)
for label, value := range rule.labels {
if value == "" {
delete(sample.Metric, label)
} else {
sample.Metric[label] = value
}
}
}
return
}
func (rule *Rule) RuleToDotGraph() string {
graph := "digraph \"Rules\" {\n"
graph += fmt.Sprintf("%#p[shape=\"box\",label=\"%v = \"];\n", rule, rule.name)
graph += fmt.Sprintf("%#p -> %#p;\n", rule, rule.vector)
graph += rule.vector.NodeTreeToDotGraph()
graph += "}\n"
return graph
}
func NewRule(name string, labels model.LabelSet, vector ast.VectorNode, permanent bool) *Rule {
return &Rule{
name: name,
labels: labels,
vector: vector,
permanent: permanent,
}
}