Revert "cleanup: remove all about v0.x" (#1918)

Revert "cleanup: remove all about v0.x (#1903)"

This reverts commit d7bcd5e998.

Signed-off-by: yxxhero <aiopsclub@163.com>

pkg/tmpl/context_funcs.go

@@ -19,6 +19,7 @@ import (
 	"github.com/helmfile/helmfile/pkg/envvar"
 	"github.com/helmfile/helmfile/pkg/helmexec"
 	"github.com/helmfile/helmfile/pkg/maputil"
+	"github.com/helmfile/helmfile/pkg/runtime"
 	"github.com/helmfile/helmfile/pkg/yaml"
 )
 
@@ -36,10 +37,23 @@ func (e DisableInsecureFeaturesError) Error() string {
 
 var (
 	disableInsecureFeatures bool
+
+	// TODO: Remove this function once Helmfile v0.x
+	skipInsecureTemplateFunctions bool
 )
 
 func init() {
 	disableInsecureFeatures, _ = strconv.ParseBool(os.Getenv(envvar.DisableInsecureFeatures))
+
+	// TODO: Remove this function once Helmfile v0.x
+	skipInsecureTemplateFunctions, _ = strconv.ParseBool(os.Getenv(envvar.SkipInsecureTemplateFunctions))
+	skipInsecureTemplateFunctions = func() bool {
+		if runtime.V1Mode {
+			return false
+		}
+		b, _ := strconv.ParseBool(os.Getenv(envvar.SkipInsecureTemplateFunctions))
+		return b
+	}()
 }
 
 func (c *Context) createFuncMap() template.FuncMap {
@@ -62,7 +76,7 @@ func (c *Context) createFuncMap() template.FuncMap {
 		"fetchSecretValue": fetchSecretValue,
 		"expandSecretRefs": fetchSecretValues,
 	}
-	if c.preRender {
+	if c.preRender || skipInsecureTemplateFunctions {
 		// disable potential side-effect template calls
 		funcMap["exec"] = func(string, []any, ...string) (string, error) {
 			return "", nil