prometheus/rules/helpers.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"
"net/url"
"strings"
clientmodel "github.com/prometheus/client_golang/model"
"github.com/prometheus/prometheus/rules/ast"
"github.com/prometheus/prometheus/utility"
)
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 NewRecordingRule(name, labels, expr.(ast.VectorNode), permanent), nil
}
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
}
func NewFunctionCall(name string, args []ast.Node) (ast.Node, error) {
function, err := ast.GetFunction(name)
if err != nil {
return nil, fmt.Errorf("Unknown function \"%v\"", name)
}
functionCall, err := ast.NewFunctionCall(function, args)
if err != nil {
return nil, fmt.Errorf(err.Error())
}
return functionCall, nil
}
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 '%v'", aggrTypeStr)
}
return ast.NewVectorAggregation(aggrType, vector.(ast.VectorNode), groupBy, keepExtraLabels), nil
}
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 \"%v\"", opTypeStr)
}
expr, err := ast.NewArithExpr(opType, lhs, rhs)
if err != nil {
return nil, fmt.Errorf(err.Error())
}
return expr, nil
}
func NewMatrix(vector ast.Node, intervalStr string) (ast.MatrixNode, error) {
switch vector.(type) {
case *ast.VectorLiteral:
{
break
}
default:
return nil, fmt.Errorf("Intervals are currently only supported for vector literals.")
}
interval, err := utility.StringToDuration(intervalStr)
if err != nil {
return nil, err
}
vectorLiteral := vector.(*ast.VectorLiteral)
return ast.NewMatrixLiteral(vectorLiteral, interval), nil
}
func ConsoleLinkForExpression(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))
}