feat: improve custom jiggler settings and add timezone support (#742)

* feat: add timezone support to jiggler and fix custom settings persistence

- Add timezone field to JigglerConfig with comprehensive IANA timezone list
- Fix custom settings not loading current values
- Remove business hours preset, add as examples in custom settings
- Improve error handling for invalid cron expressions

* fix: format jiggler.go with gofmt

* fix: add embedded timezone data and validation

- Import time/tzdata to embed timezone database in binary
- Add timezone validation in runJigglerCronTab() to gracefully fallback to UTC
- Add timezone to debug logging in rpcSetJigglerConfig
- Fixes 'unknown time zone' errors when system lacks timezone data

* refactor: add timezone field comments from jiggler options

* chore: move tzdata to backend

* refactor: fix JigglerSetting linting

- Adjusted useEffect dependency to include send function for better data fetching
- Modified layout classes for improved responsiveness and consistency
- Cleaned up code formatting for better readability

---------

Co-authored-by: Siyuan Miao <[email protected]>

Author: adamshiervani

Makefile

@@ -8,7 +8,7 @@ VERSION ?= 0.4.6
 PROMETHEUS_TAG := github.com/prometheus/common/version
 KVM_PKG_NAME := github.com/jetkvm/kvm
 
-GO_BUILD_ARGS := -tags netgo
+GO_BUILD_ARGS := -tags netgo -tags timetzdata
 GO_RELEASE_BUILD_ARGS := -trimpath $(GO_BUILD_ARGS)
 GO_LDFLAGS := \
   -s -w \

config.go

@@ -123,6 +123,7 @@ var defaultConfig = &Config{
 		InactivityLimitSeconds: 60,
 		JitterPercentage:       25,
 		ScheduleCronTab:        "0 * * * * *",
+		Timezone:               "UTC",
 	},
 	TLSMode: "",
 	UsbConfig: &usbgadget.Config{

internal/tzdata/gen.go

@@ -0,0 +1,72 @@
+//go:build ignore
+
+package main
+
+import (
+	"archive/zip"
+	"bytes"
+	"flag"
+	"fmt"
+	"os"
+	"text/template"
+)
+
+var tmpl = `// Code generated by "go run gen.go". DO NOT EDIT.
+//go:generate env ZONEINFO=$GOROOT/lib/time/zoneinfo.zip go run gen.go -output tzdata.go
+package tzdata
+var TimeZones = []string{
+	{{- range . }}
+	"{{.}}",
+	{{- end }}
+}
+`
+
+var filename = flag.String("output", "tzdata.go", "output file name")
+
+func main() {
+	flag.Parse()
+
+	path := os.Getenv("ZONEINFO")
+	if path == "" {
+		fmt.Println("ZONEINFO is not set")
+		os.Exit(1)
+	}
+
+	if _, err := os.Stat(path); os.IsNotExist(err) {
+		fmt.Printf("ZONEINFO %s does not exist\n", path)
+		os.Exit(1)
+	}
+
+	zipfile, err := zip.OpenReader(path)
+	if err != nil {
+		fmt.Printf("Error opening ZONEINFO %s: %v\n", path, err)
+		os.Exit(1)
+	}
+	defer zipfile.Close()
+
+	timezones := []string{}
+
+	for _, file := range zipfile.File {
+		timezones = append(timezones, file.Name)
+	}
+
+	var buf bytes.Buffer
+
+	tmpl, err := template.New("tzdata").Parse(tmpl)
+	if err != nil {
+		fmt.Printf("Error parsing template: %v\n", err)
+		os.Exit(1)
+	}
+
+	err = tmpl.Execute(&buf, timezones)
+	if err != nil {
+		fmt.Printf("Error executing template: %v\n", err)
+		os.Exit(1)
+	}
+
+	err = os.WriteFile(*filename, buf.Bytes(), 0644)
+	if err != nil {
+		fmt.Printf("Error writing file %s: %v\n", *filename, err)
+		os.Exit(1)
+	}
+}