Fix zuul.conf render

This change fixes the way zuul.conf file is rendered.
Before zuul.config file the keys under each section were ordered by the
order they were added to the section.
Now we sort each section before writing into the secret.

Change-Id: I30859f9809b4d27b06272e5d7ad6ad00590ba72d

Author: fserucas

controllers/zuul.go

@@ -8,6 +8,7 @@ import (
 	_ "embed"
 	"fmt"
 	"regexp"
+	"sort"
 	"strconv"
 	"strings"
 
@@ -1452,7 +1453,29 @@ func LoadConfigINI(zuulConf string) *ini.File {
 }
 
 func DumpConfigINI(cfg *ini.File) string {
+
 	writer := bytes.NewBufferString("")
+	sections := cfg.Sections()
+
+	for _, section := range sections {
+
+		keys := section.Keys()
+		sortedKeys := []*ini.Key{}
+
+		sort.Slice(keys, func(i, j int) bool {
+			return keys[i].Name() < keys[j].Name()
+		})
+
+		for _, key := range keys {
+			sortedKeys = append(sortedKeys, key)
+			section.DeleteKey(key.Name())
+		}
+
+		for _, key := range sortedKeys {
+			section.NewKey(key.Name(), key.Value())
+		}
+
+	}
 	cfg.WriteTo(writer)
 	return writer.String()
 }