def launch()

in lib/muchos/ec2.py [0:0]

• 48 lines of code
• 8 McCabe index (conditional complexity)

    def launch(self):
        if self.active_nodes():
            exit(
                "ERROR - There are already instances "
                "running for {0} cluster".format(self.config.cluster_name)
            )

        if path.isfile(self.config.hosts_path):
            exit(
                "ERROR - A hosts file already exists at {0}. "
                "Please delete before running launch again".format(
                    self.config.hosts_path
                )
            )

        self.config.verify_launch()

        print("Launching {0} cluster".format(self.config.cluster_name))

        if self.config.has_option("ec2", "security_group_id"):
            sg_id = self.config.get("ec2", "security_group_id")
        else:
            sg_id = self.create_security_group()

        instance_d = {}
        for (hostname, services) in list(self.config.nodes().items()):
            instance = self.launch_node(hostname, services, sg_id)
            instance_d[instance["InstanceId"]] = hostname

        num_running = len(self.get_status(["running"]))
        num_expected = len(self.config.nodes())
        while num_running != num_expected:
            print(
                "{0} of {1} nodes have started. "
                "Waiting another 5 sec..".format(num_running, num_expected)
            )
            time.sleep(5)
            num_running = len(self.get_status(["running"]))

        with open(self.config.hosts_path, "w") as hosts_file:
            for instance in self.get_status(["running"]):
                public_ip = ""
                if "PublicIpAddress" in instance:
                    public_ip = instance["PublicIpAddress"]
                private_ip = instance["PrivateIpAddress"]
                hostname = instance_d[instance["InstanceId"]]
                print(
                    "{0} {1} {2}".format(hostname, private_ip, public_ip),
                    file=hosts_file,
                )

        print(
            "All {0} nodes have started. Created hosts file at {1}".format(
                num_expected, self.config.hosts_path
            )
        )