Output single list of json objects

cmd/cli/cmd_topn.go

@@ -33,6 +33,10 @@ func runTopN(args []string) {
 
 	results := fanOutTopN(sf.targets, filter, grp, *n, win)
 
+	if sf.jsonOut {
+		printTopNJSONArray(results)
+		return
+	}
 	for _, r := range results {
 		if hdr := targetHeader(r.target, r.resp.GetSource(), len(sf.targets)); hdr != "" {
 			fmt.Println(hdr)
@@ -41,11 +45,7 @@ func runTopN(args []string) {
 			fmt.Fprintf(os.Stderr, "error from %s: %v\n", r.target, r.err)
 			continue
 		}
-		if sf.jsonOut {
-			printTopNJSON(r)
-		} else {
-			printTopNTable(r)
-		}
+		printTopNTable(r)
 		if len(sf.targets) > 1 {
 			fmt.Println()
 		}
@@ -99,7 +99,7 @@ func printTopNTable(r topNResult) {
 	printTable(os.Stdout, rows)
 }
 
-func printTopNJSON(r topNResult) {
+func printTopNJSONArray(results []topNResult) {
 	type entry struct {
 		Label string `json:"label"`
 		Count int64  `json:"count"`
@@ -109,14 +109,22 @@ func printTopNJSON(r topNResult) {
 		Target  string  `json:"target"`
 		Entries []entry `json:"entries"`
 	}
-	o := out{
-		Source:  r.resp.Source,
-		Target:  r.target,
-		Entries: make([]entry, len(r.resp.Entries)),
+	rows := make([]out, 0, len(results))
+	for _, r := range results {
+		if r.err != nil {
+			fmt.Fprintf(os.Stderr, "error from %s: %v\n", r.target, r.err)
+			continue
+		}
+		o := out{
+			Source:  r.resp.Source,
+			Target:  r.target,
+			Entries: make([]entry, len(r.resp.Entries)),
+		}
+		for i, e := range r.resp.Entries {
+			o.Entries[i] = entry{Label: e.Label, Count: e.Count}
+		}
+		rows = append(rows, o)
 	}
-	for i, e := range r.resp.Entries {
-		o.Entries[i] = entry{Label: e.Label, Count: e.Count}
-	}
-	b, _ := json.Marshal(o)
+	b, _ := json.Marshal(rows)
 	fmt.Println(string(b))
 }