def preload_image(self, image_name):
        def _preload(node, zone):
            split = node.split()
            if len(split) > 0:
                node_name = split[0]
                if node_name in "kubernetes-master":
                    info_log(self.TAG, "Preloading {0} onto {1}...".format(image_name, node_name))
                    docker_cmd = "sudo gcloud docker pull {0}/{1}".format(MainSettings.REGISTRY_NAME, image_name)
                    cmd = ["gcloud", "compute", "ssh", node_name, "--zone", zone,
                           "--command", "{}".format(docker_cmd)]
                    return subprocess.Popen(cmd)
            return None
        procs = self._nodes_command(_preload)
        info_log(self.TAG, "Waiting for preloading to finish...")
        for proc in procs:
            if proc:
                proc.wait()
        info_log(self.TAG, "Preloaded image {} onto all nodes".format(image_name))
        return True
dataset/ETHPy150Open binder-project/binder/binder/cluster.py/KubernetesManager.preload_image/operator `!=` -> `in`