From 980320026391bd02d8d4f616725116694492a2df Mon Sep 17 00:00:00 2001
From: Anders Janmyr <anders@janmyr.com>
Date: Wed, 2 May 2018 11:04:11 -0700
Subject: [PATCH] Add support for running out-of-cluster with KUBERNETES_CONFIG

Allows testing the operator without dockerizing it and deploying it to a cluster.
---
 pkg/k8sclient/client.go | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/pkg/k8sclient/client.go b/pkg/k8sclient/client.go
index 96d29c9fba..86be64a2eb 100644
--- a/pkg/k8sclient/client.go
+++ b/pkg/k8sclient/client.go
@@ -27,6 +27,7 @@ import (
 	"k8s.io/client-go/dynamic"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/rest"
+	"k8s.io/client-go/tools/clientcmd"
 )
 
 var (
@@ -84,8 +85,15 @@ func apiResource(gvk schema.GroupVersionKind, restMapper *discovery.DeferredDisc
 }
 
 // mustNewKubeClientAndConfig returns the in-cluster config and kubernetes client
+// or if KUBERNETES_CONFIG is given an out of cluster config and client
 func mustNewKubeClientAndConfig() (kubernetes.Interface, *rest.Config) {
-	cfg, err := inClusterConfig()
+	var cfg *rest.Config
+	var err error
+	if os.Getenv("KUBERNETES_CONFIG") != "" {
+		cfg, err = outOfClusterConfig()
+	} else {
+		cfg, err = inClusterConfig()
+	}
 	if err != nil {
 		panic(err)
 	}
@@ -99,7 +107,7 @@ func inClusterConfig() (*rest.Config, error) {
 	if len(os.Getenv("KUBERNETES_SERVICE_HOST")) == 0 {
 		addrs, err := net.LookupHost("kubernetes.default.svc")
 		if err != nil {
-			panic(err)
+			return nil, err
 		}
 		os.Setenv("KUBERNETES_SERVICE_HOST", addrs[0])
 	}
@@ -108,3 +116,9 @@ func inClusterConfig() (*rest.Config, error) {
 	}
 	return rest.InClusterConfig()
 }
+
+func outOfClusterConfig() (*rest.Config, error) {
+	kubeconfig := os.Getenv("KUBERNETES_CONFIG")
+	config, err := clientcmd.BuildConfigFromFlags("", kubeconfig)
+	return config, err
+}