added rest client passed with action configuration

Signed-off-by: raffaelespazzoli <raffaele.spazzoli@gmail.com>

pkg/action/install.go

@@ -436,7 +436,12 @@ func (c *Configuration) renderResources(ch *chart.Chart, values chartutil.Values
 		}
 	}
 
-	files, err := engine.Render(ch, values)
+	rest, err := c.RESTClientGetter.ToRESTConfig()
+	if err != nil {
+		return hs, b, "", err
+	}
+
+	files, err := engine.RenderWithClient(ch, values, rest)
 	if err != nil {
 		return hs, b, "", err
 	}

pkg/engine/engine.go

@@ -27,6 +27,7 @@ import (
 	"text/template"
 
 	"github.com/pkg/errors"
+	"k8s.io/client-go/rest"
 
 	"helm.sh/helm/v3/pkg/chart"
 	"helm.sh/helm/v3/pkg/chartutil"
@@ -39,6 +40,8 @@ type Engine struct {
 	Strict bool
 	// In LintMode, some 'required' template values may be missing, so don't fail
 	LintMode bool
+	// the rest config to connect to te kubernetes api
+	config *rest.Config
 }
 
 // Render takes a chart, optional values, and value overrides, and attempts to render the Go templates.
@@ -71,6 +74,15 @@ func Render(chrt *chart.Chart, values chartutil.Values) (map[string]string, erro
 	return new(Engine).Render(chrt, values)
 }
 
+// RenderWithClient takes a chart, optional values, and value overrides, and attempts to
+// render the Go templates using the default options. This engine is client aware and so can have template
+// functions that interact with the client
+func RenderWithClient(chrt *chart.Chart, values chartutil.Values, config *rest.Config) (map[string]string, error) {
+	return Engine{
+		config: config,
+	}.Render(chrt, values)
+}
+
 // renderable is an object that can be rendered.
 type renderable struct {
 	// tpl is the current template.
@@ -157,6 +169,9 @@ func (e Engine) initFunMap(t *template.Template, referenceTpls map[string]render
 		}
 		return val, nil
 	}
+	if e.config != nil {
+		funcMap["lookup"] = NewLookupFunction(e.config)
+	}
 
 	t.Funcs(funcMap)
 }

pkg/engine/funcs.go

@@ -53,7 +53,6 @@ func funcMap() template.FuncMap {
 		"fromYaml": fromYAML,
 		"toJson":   toJSON,
 		"fromJson": fromJSON,
-		"lookup":   lookup,
 
 		// This is a placeholder for the "include" function, which is
 		// late-bound to a template. By declaring it here, we preserve the

pkg/engine/lookup_func.go

@@ -17,10 +17,7 @@ limitations under the License.
 package engine
 
 import (
-	"flag"
 	"log"
-	"os"
-	"path/filepath"
 	"strings"
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -28,38 +25,14 @@ import (
 	"k8s.io/client-go/discovery"
 	"k8s.io/client-go/dynamic"
 	"k8s.io/client-go/rest"
-	"k8s.io/client-go/tools/clientcmd"
 )
 
-var config *rest.Config
+type lookupFunc = func(apiversion string, resource string, namespace string, name string) (map[string]interface{}, error)
 
-func init() {
+func NewLookupFunction(config *rest.Config) lookupFunc {
-	// try the out-cluster config, this will default to the in-cluster config is not successful
+	return func(apiversion string, resource string, namespace string, name string) (map[string]interface{}, error) {
-	var kubeconfig *string
-	if home := homeDir(); home != "" {
-		kubeconfig = flag.String("kubeconfig", filepath.Join(home, ".kube", "config"), "(optional) absolute path to the kubeconfig file")
-	} else {
-		kubeconfig = flag.String("kubeconfig", "", "absolute path to the kubeconfig file")
-	}
-	flag.Parse()
-
-	// use the current context in kubeconfig
-	config1, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
-	if err == nil {
-		config = config1
-	}
-}
-
-func homeDir() string {
-	if h := os.Getenv("HOME"); h != "" {
-		return h
-	}
-	return os.Getenv("USERPROFILE") // windows
-}
-
-func lookup(apiversion string, resource string, namespace string, name string) (map[string]interface{}, error) {
 		var client dynamic.ResourceInterface
-	c, namespaced, err := getDynamicClientOnKind(apiversion, resource)
+		c, namespaced, err := getDynamicClientOnKind(apiversion, resource, config)
 		if err != nil {
 			return map[string]interface{}{}, err
 		}
@@ -82,13 +55,20 @@ func lookup(apiversion string, resource string, namespace string, name string) (
 			return map[string]interface{}{}, err
 		}
 		return obj.Object, nil
-
 	}
+}
+
+// func homeDir() string {
+// 	if h := os.Getenv("HOME"); h != "" {
+// 		return h
+// 	}
+// 	return os.Getenv("USERPROFILE") // windows
+// }
 
 // GetDynamicClientOnUnstructured returns a dynamic client on an Unstructured type. This client can be further namespaced.
-func getDynamicClientOnKind(apiversion string, kind string) (dynamic.NamespaceableResourceInterface, bool, error) {
+func getDynamicClientOnKind(apiversion string, kind string, config *rest.Config) (dynamic.NamespaceableResourceInterface, bool, error) {
 	gvk := schema.FromAPIVersionAndKind(apiversion, kind)
-	apiRes, err := getAPIReourceForGVK(gvk)
+	apiRes, err := getAPIReourceForGVK(gvk, config)
 	if err != nil {
 		log.Printf("[ERROR] unable to get apiresource from unstructured: %s , error %s", gvk.String(), err)
 		return nil, false, err
@@ -107,7 +87,7 @@ func getDynamicClientOnKind(apiversion string, kind string) (dynamic.Namespaceab
 	return res, apiRes.Namespaced, nil
 }
 
-func getAPIReourceForGVK(gvk schema.GroupVersionKind) (metav1.APIResource, error) {
+func getAPIReourceForGVK(gvk schema.GroupVersionKind, config *rest.Config) (metav1.APIResource, error) {
 	res := metav1.APIResource{}
 	discoveryClient, err := discovery.NewDiscoveryClientForConfig(config)
 	if err != nil {