Wrap Kubernetes host address in square brackets

When constructing the host address string, the address is
not wrapped in square brackets. This does not work in IPv6
Kubernetes deployments. This commit adds square brackets
around the address. IPv4 was also tested to ensure it works
with wrapped address.

Signed-off-by: Jerry Sun <jerry.sun@windriver.com>

storage/kubernetes/client.go

@@ -415,6 +415,9 @@ func inClusterConfig() (cluster k8sapi.Cluster, user k8sapi.AuthInfo, namespace
 		err = fmt.Errorf("unable to load in-cluster configuration, KUBERNETES_SERVICE_HOST and KUBERNETES_SERVICE_PORT must be defined")
 		return
 	}
+	// we need to wrap IPv6 addresses in square brackets
+	// IPv4 also works with square brackets
+	host = "[" + host + "]"
 	cluster = k8sapi.Cluster{
 		Server:               "https://" + host + ":" + port,
 		CertificateAuthority: "/var/run/secrets/kubernetes.io/serviceaccount/ca.crt",