prometheus/api/query.go

package api

import (
	"code.google.com/p/gorest"
	"github.com/matttproud/prometheus/rules"
	"github.com/matttproud/prometheus/rules/ast"
	"time"
)

func (serv MetricsService) Query(Expr string, Json string, Start string, End string) (result string) {
	exprNode, err := rules.LoadExprFromString(Expr)
	if err != nil {
		return err.Error()
	}

	timestamp := time.Now()

	rb := serv.ResponseBuilder()
	var format ast.OutputFormat
	if Json != "" {
		format = ast.JSON
		rb.SetContentType(gorest.Application_Json)
	} else {
		format = ast.TEXT
		rb.SetContentType(gorest.Text_Plain)
	}

	return ast.EvalToString(exprNode, &timestamp, format)
}