Add some duration function to the template engine

Add toSeconds function to convert duration to seconds
Add toMilliSeconds function to convert duration to milliseconds

It's related to: #11974

Signed-off-by: Ehsan Karimi <karimiehsan901@gmail.com>

pkg/engine/funcs.go

@@ -21,6 +21,7 @@ import (
 	"encoding/json"
 	"strings"
 	"text/template"
+	"time"
 
 	"github.com/BurntSushi/toml"
 	"github.com/Masterminds/sprig/v3"
@@ -30,8 +31,8 @@ import (
 // funcMap returns a mapping of all of the functions that Engine has.
 //
 // Because some functions are late-bound (e.g. contain context-sensitive
-// data), the functions may not all perform identically outside of an Engine
+// data), the functions may not all perform identically outside an Engine
-// as they will inside of an Engine.
+// as they will inside an Engine.
 //
 // Known late-bound functions:
 //
@@ -54,6 +55,8 @@ func funcMap() template.FuncMap {
 		"toJson":         toJSON,
 		"fromJson":       fromJSON,
 		"fromJsonArray":  fromJSONArray,
+		"toSeconds":      toSeconds,
+		"toMilliSeconds": toMilliSeconds,
 
 		// This is a placeholder for the "include" function, which is
 		// late-bound to a template. By declaring it here, we preserve the
@@ -82,7 +85,7 @@ func funcMap() template.FuncMap {
 func toYAML(v interface{}) string {
 	data, err := yaml.Marshal(v)
 	if err != nil {
-		// Swallow errors inside of a template.
+		// Swallow errors inside a template.
 		return ""
 	}
 	return strings.TrimSuffix(string(data), "\n")
@@ -139,7 +142,7 @@ func toTOML(v interface{}) string {
 func toJSON(v interface{}) string {
 	data, err := json.Marshal(v)
 	if err != nil {
-		// Swallow errors inside of a template.
+		// Swallow errors inside a template.
 		return ""
 	}
 	return string(data)
@@ -174,3 +177,27 @@ func fromJSONArray(str string) []interface{} {
 	}
 	return a
 }
+
+// toSeconds converts a duration string to seconds
+//
+// For example for 1h it will be 3600
+func toSeconds(str string) float64 {
+	duration, err := time.ParseDuration(str)
+	if err != nil {
+		// Swallow errors inside a template.
+		return 0
+	}
+	return duration.Seconds()
+}
+
+// toMilliSeconds converts a duration string to milliseconds
+//
+// For example for 1h it will be 3600000
+func toMilliSeconds(str string) int64 {
+	duration, err := time.ParseDuration(str)
+	if err != nil {
+		// Swallow errors inside a template.
+		return 0
+	}
+	return duration.Milliseconds()
+}

pkg/engine/funcs_test.go

@@ -99,6 +99,14 @@ func TestFuncs(t *testing.T) {
 		tpl:    `{{ lookup "v1" "Namespace" "" "unlikelynamespace99999999" }}`,
 		expect: `map[]`,
 		vars:   `["one", "two"]`,
+	}, {
+		tpl:    `{{ toSeconds .duration }}`,
+		expect: "3600",
+		vars:   map[string]interface{}{"duration": "1h"},
+	}, {
+		tpl:    `{{ toMilliSeconds .duration }}`,
+		expect: "3600000",
+		vars:   map[string]interface{}{"duration": "1h"},
 	}}
 
 	for _, tt := range tests {