Support label templating v1 PROPOSED

Noam Preil: 1
 Support label templating

 1 files changed, 31 insertions(+), 1 deletions(-)

[PATCH] Support label templating Export this patch

---
 main.go | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/main.go b/main.go
index 12c5491..69fcca1 100644
--- a/main.go
+++ b/main.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
 	"image/color"
@@ -11,6 +12,7 @@ import (
 	"sort"
 	"strconv"
 	"strings"
+	"text/template"
 	"time"
 
 	"github.com/dustin/go-humanize"
@@ -166,6 +168,12 @@ func registerExtension(router chi.Router, extension string, mime string) {
 			legend = l[0]
 		}
 
+		// Label template
+		var label string
+		if l, ok := args["label"]; ok {
+			label = l[0]
+		}
+
 		// Set step so that there's approximately 25 data points per inch
 		step := int(end.Sub(start).Seconds() / (25 * float64(width / vg.Inch)))
 		if s, ok := args["step"]; ok {
@@ -240,7 +248,29 @@ func registerExtension(router chi.Router, extension string, mime string) {
 				nextColor = 0
 			}
 			plotters[i] = l
-			if legend != "" {
+			if label != "" && len(res.Metric) > 2 && res.Metric[0] == '{' && res.Metric[len(res.Metric)-1] == '}' {
+				raw := res.Metric[1 : len(res.Metric)-1]
+				raw_tags := strings.Split(raw, ",")
+				tags := make(map[string]string)
+				for _, v := range raw_tags {
+					tag := strings.Split(v, "=")
+					if len(tag) != 2 {
+						log.Printf("Expected tag format: 'name=value'!")
+						continue
+					}
+					if len(tag[1]) > 2 && tag[1][0] == '"' && tag[1][len(tag[1])-1] == '"' {
+						tags[tag[0]] = tag[1][1 : len(tag[1])-1]
+					}
+				}
+				tmpl, err := template.New("label").Parse(label)
+				if err != nil {
+					log.Printf("Failed to parse label template: ", err)
+				} else {
+					var label_out bytes.Buffer
+					tmpl.Execute(&label_out, tags)
+					p.Legend.Add(label_out.String(), l)
+				}
+			} else if legend != "" {
 				p.Legend.Add(legend, l)
 			} else {
 				p.Legend.Add(res.Metric, l)
-- 
2.28.0

Drew DeVault

2 months ago

Can you move the bulk of this to a separate function?

Can you verify that any SVG markup is correctly escaped if the user
specifies a template with SVG elements in it?