Merge pull request #3 from WoodProgrammer/label-fetcher

Supports for dynamic label fetching and migration

Author: WoodProgrammer

cmd/prometheus.go

@@ -6,21 +6,20 @@ import (
 	"net/http"
 	"os/exec"
 
-	lib "github.com/WoodProgrammer/prom-migrator/lib"
 	"github.com/rs/zerolog/log"
 )
 
 type Prometheus interface {
-	FetchPrometheusData(url string) lib.PrometheusData
+	FetchPrometheusData(url string) map[string]interface{}
 	ImportPrometheusData(file, targetDir string) error
 	ExecutePromtoolCommand(args ...string) (string, error)
 }
 
 type PromClient struct {
 }
 
-func (promClient *PromClient) FetchPrometheusData(url string) lib.PrometheusData {
-	var metric lib.PrometheusData
+func (promClient *PromClient) FetchPrometheusData(url string) map[string]interface{} {
+	var metric map[string]interface{}
 
 	resp, err := http.Get(url)
 	if err != nil {

lib/types.go

@@ -3,19 +3,3 @@ package lib
 const (
 	DirMode = 0777
 )
-
-type PrometheusData struct {
-	Status string `json:"status"`
-	Data   Data
-}
-
-type Data struct {
-	ResultType string `json:"resultType"`
-	Result     []Result
-}
-type Result struct {
-	Metric   string          `json:"__name__"`
-	Instance string          `json:"string"`
-	Job      string          `json:"job"`
-	Values   [][]interface{} `json:"values"`
-}

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"strings"
@@ -35,15 +36,55 @@ func CallPrometheus() {
 	}
 	url := fmt.Sprintf("http://%s:%s/api/v1/query_range?query=%s&start=%s&end=%s&step=%s",
 		promHost, promPort, query, startStamp, endStamp, step)
-	fmt.Println("The url is ", url)
 	data := newPrometheusClient.FetchPrometheusData(url)
 	rawMetricData = append(rawMetricData, fmt.Sprintf("# TYPE %s counter", strings.Split(query, "{")[0]))
 
-	for _, result := range data.Data.Result {
-		for _, k := range result.Values {
-			line := fmt.Sprintf("%s %f %s", query, k[0], k[1])
-			rawMetricData = append(rawMetricData, line)
+	parsedData, ok := data["data"].(map[string]interface{})
+
+	if !ok {
+		err := errors.New("json parsing error on rawPrometheus data ")
+		log.Err(err).Msg("Error parsing 'data'")
+		return
+	}
+
+	results, ok := parsedData["result"].([]interface{})
+	if !ok {
+		err := errors.New("json parsing error on parsedData['result'] data ")
+		log.Err(err).Msg("Error parsing 'result'")
+		return
+	}
+
+	for _, r := range results {
+
+		result, ok := r.(map[string]interface{})
+		if !ok {
+			continue
 		}
+		labelMap := []string{}
+		metric, ok := result["metric"].(map[string]interface{})
+
+		metricName, ok := metric["__name__"].(string)
+		if ok {
+			for key, value := range metric {
+
+				if key != "__name__" {
+					labelMap = append(labelMap, fmt.Sprintf(`%s="%s"`, key, value))
+				}
+			}
+			query := fmt.Sprintf(`%s{%s}`, metricName, strings.Join(labelMap, ","))
+
+			values, ok := result["values"].([]interface{})
+			if ok {
+				for _, v := range values {
+					valArr, ok := v.([]interface{})
+					if ok && len(valArr) == 2 {
+						tmpData := fmt.Sprintf("%s %v %v", query, valArr[0], valArr[1])
+						rawMetricData = append(rawMetricData, tmpData)
+					}
+				}
+			}
+		}
+
 	}
 	rawMetricData = append(rawMetricData, fmt.Sprintf("# EOF"))