prometheus/rules/helpers.go

173 lines
6.0 KiB
Go

// Copyright 2013 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 rules
import (
"fmt"
"net/url"
"strings"
clientmodel "github.com/prometheus/client_golang/model"
"github.com/prometheus/prometheus/rules/ast"
"github.com/prometheus/prometheus/storage/metric"
"github.com/prometheus/prometheus/utility"
)
// CreateRecordingRule is a convenience function to create a recording rule.
func CreateRecordingRule(name string, labels clientmodel.LabelSet, expr ast.Node, permanent bool) (*RecordingRule, error) {
if _, ok := expr.(ast.VectorNode); !ok {
return nil, fmt.Errorf("recording rule expression %v does not evaluate to vector type", expr)
}
return &RecordingRule{
name: name,
labels: labels,
vector: expr.(ast.VectorNode),
permanent: permanent,
}, nil
}
// CreateAlertingRule is a convenience function to create a new alerting rule.
func CreateAlertingRule(name string, expr ast.Node, holdDurationStr string, labels clientmodel.LabelSet, summary string, description string) (*AlertingRule, error) {
if _, ok := expr.(ast.VectorNode); !ok {
return nil, fmt.Errorf("alert rule expression %v does not evaluate to vector type", expr)
}
holdDuration, err := utility.StringToDuration(holdDurationStr)
if err != nil {
return nil, err
}
return NewAlertingRule(name, expr.(ast.VectorNode), holdDuration, labels, summary, description), nil
}
// NewFunctionCall is a convenience function to create a new AST function-call node.
func NewFunctionCall(name string, args []ast.Node) (ast.Node, error) {
function, err := ast.GetFunction(name)
if err != nil {
return nil, fmt.Errorf("unknown function %q", name)
}
functionCall, err := ast.NewFunctionCall(function, args)
if err != nil {
return nil, fmt.Errorf(err.Error())
}
return functionCall, nil
}
// NewVectorAggregation is a convenience function to create a new AST vector aggregation.
func NewVectorAggregation(aggrTypeStr string, vector ast.Node, groupBy clientmodel.LabelNames, keepExtraLabels bool) (*ast.VectorAggregation, error) {
if _, ok := vector.(ast.VectorNode); !ok {
return nil, fmt.Errorf("operand of %v aggregation must be of vector type", aggrTypeStr)
}
var aggrTypes = map[string]ast.AggrType{
"SUM": ast.Sum,
"MAX": ast.Max,
"MIN": ast.Min,
"AVG": ast.Avg,
"COUNT": ast.Count,
}
aggrType, ok := aggrTypes[aggrTypeStr]
if !ok {
return nil, fmt.Errorf("unknown aggregation type %q", aggrTypeStr)
}
return ast.NewVectorAggregation(aggrType, vector.(ast.VectorNode), groupBy, keepExtraLabels), nil
}
// NewArithExpr is a convenience function to create a new AST arithmetic expression.
func NewArithExpr(opTypeStr string, lhs ast.Node, rhs ast.Node) (ast.Node, error) {
var opTypes = map[string]ast.BinOpType{
"+": ast.Add,
"-": ast.Sub,
"*": ast.Mul,
"/": ast.Div,
"%": ast.Mod,
">": ast.GT,
"<": ast.LT,
"==": ast.EQ,
"!=": ast.NE,
">=": ast.GE,
"<=": ast.LE,
"AND": ast.And,
"OR": ast.Or,
}
opType, ok := opTypes[opTypeStr]
if !ok {
return nil, fmt.Errorf("invalid binary operator %q", opTypeStr)
}
expr, err := ast.NewArithExpr(opType, lhs, rhs)
if err != nil {
return nil, fmt.Errorf(err.Error())
}
return expr, nil
}
// NewVectorSelector is a convenience function to create a new AST vector selector.
func NewVectorSelector(m metric.LabelMatchers, offsetStr string) (ast.VectorNode, error) {
offset, err := utility.StringToDuration(offsetStr)
if err != nil {
return nil, err
}
return ast.NewVectorSelector(m, offset), nil
}
// NewMatrixSelector is a convenience function to create a new AST matrix selector.
func NewMatrixSelector(vector ast.Node, intervalStr string, offsetStr string) (ast.MatrixNode, error) {
interval, err := utility.StringToDuration(intervalStr)
if err != nil {
return nil, err
}
offset, err := utility.StringToDuration(offsetStr)
if err != nil {
return nil, err
}
vectorSelector, ok := vector.(*ast.VectorSelector)
if !ok {
return nil, fmt.Errorf("intervals are currently only supported for vector selectors")
}
return ast.NewMatrixSelector(vectorSelector, interval, offset), nil
}
func newLabelMatcher(matchTypeStr string, name clientmodel.LabelName, value clientmodel.LabelValue) (*metric.LabelMatcher, error) {
matchTypes := map[string]metric.MatchType{
"=": metric.Equal,
"!=": metric.NotEqual,
"=~": metric.RegexMatch,
"!~": metric.RegexNoMatch,
}
matchType, ok := matchTypes[matchTypeStr]
if !ok {
return nil, fmt.Errorf("invalid label matching operator %q", matchTypeStr)
}
return metric.NewLabelMatcher(matchType, name, value)
}
// TableLinkForExpression creates an escaped relative link to the table view of
// the provided expression.
func TableLinkForExpression(expr string) string {
// url.QueryEscape percent-escapes everything except spaces, for which it
// uses "+". However, in the non-query part of a URI, only percent-escaped
// spaces are legal, so we need to manually replace "+" with "%20" after
// query-escaping the string.
//
// See also:
// http://stackoverflow.com/questions/1634271/url-encoding-the-space-character-or-20.
urlData := url.QueryEscape(fmt.Sprintf(`[{"expr":%q,"tab":1}]`, expr))
return fmt.Sprintf("/graph#%s", strings.Replace(urlData, "+", "%20", -1))
}
// GraphLinkForExpression creates an escaped relative link to the graph view of
// the provided expression.
func GraphLinkForExpression(expr string) string {
urlData := url.QueryEscape(fmt.Sprintf(`[{"expr":%q,"tab":0}]`, expr))
return fmt.Sprintf("/graph#%s", strings.Replace(urlData, "+", "%20", -1))
}