Rewrite urlgen in Go

Cut-n-paste Ben's code.

Fix bugs re args.

Sandardize on 1-based for time and servers.

Keep incrementing time for subsequent clients -- I don't see the
point in overwriting data.

tests/urlgen/urlgen.go

@@ -1,49 +1,43 @@
 package main
 
 import (
+	"encoding/json"
 	"flag"
 	"fmt"
 	"time"
 )
 
-var (
-	i, s, c int
-)
-
-func init() {
-	flag.IntVar(&i, "i", 10, "interval")
-	flag.IntVar(&s, "s", 1, "Number of unique series to generate.")
-	flag.IntVar(&c, "c", 10, "Number of clients to simulate.")
-}
-
 func main() {
+	intervalN := flag.Int("interval", 10, "interval")
+	seriesN := flag.Int("series", 1, "Number of unique series to generate.")
+	clientN := flag.Int("clients", 10, "Number of clients to simulate.")
 	flag.Parse()
 
-	var (
-		pointsInSeries string
-		j              int = 1
-		k              int
-		printComma     string = ","
-		jsonTemplate   string = `{"name": "cpu", "tags": {"host": "server%d"}, "timestamp": "%s","fields": {"value": 100}}%s`
-		urlTemplate    string = `http://localhost:8086/write POST {"database" : "db", "retentionPolicy" : "raw", "points": [%s]}`
-	)
-
 	t := time.Date(2010, time.January, 1, 8, 0, 0, 0, time.UTC)
-	for ; c > 0; c-- {
-		for ; j < s+1; j++ {
-			for ; k < i; k++ {
-				if k == i-1 {
-					printComma = ""
-				}
-				pointsInSeries = pointsInSeries + fmt.Sprintf(jsonTemplate, j, t.Format(time.RFC3339), printComma)
-				t = t.Add(1 * time.Second)
+	oneSecond := 1 * time.Second
+
+	for i := 0; i < *clientN; i++ {
+		for j := 0; j < *seriesN; j++ {
+			points := make([]*Point, 0)
+			for k := 0; k < *intervalN; k++ {
+				t = t.Add(oneSecond)
+				points = append(points, &Point{
+					Name:      "cpu",
+					Timestamp: t,
+					Tags:      map[string]string{"host": fmt.Sprintf("server%d", j+1)},
+					Fields:    map[string]interface{}{"value": 100},
+				})
 			}
-			fmt.Printf(urlTemplate, pointsInSeries)
-			fmt.Println()
-			pointsInSeries = ""
-			k = 0
-			printComma = ","
+			buf, _ := json.Marshal(points)
+
+			fmt.Printf("http://localhost:8086/write POST %s\n", buf)
 		}
-		j = 1
 	}
 }
+
+type Point struct {
+	Name      string                 `json:"name"`
+	Timestamp time.Time              `json:"timestamp"`
+	Tags      map[string]string      `json:"tags"`
+	Fields    map[string]interface{} `json:"fields"`
+}