# Buggy code
def docker_start_cmds(user, image, mount, cname, user_options):
    cmds = []

    # create flags
    # ports for the redis, object manager, and tune client
    port_flags = " ".join(
        ["-p {port}:{port}".format(port=port) for port in ["6379", "8076", "4321"]]
    )
    mount_flags = " ".join(
        ["-v {src}:{dest}".format(src=k, dest=v) for k, v in mount.items()]
    )

    # for click, used in ray cli
    env_vars = {"LC_ALL": "C.UTF-8", "LANG": "C.UTF-8"}
    env_flags = " ".join(
        ["-e {name}={val}".format(name=k, val=v) for k, v in env_vars.items()]
    )

    user_options_str = " ".join(user_options)
    # docker run command
    docker_check = ["docker", "inspect", "-f", "'{{.State.Running}}'", cname, "||"]
    docker_run = [
        "docker",
        "run",
        "--rm",
        "--name {}".format(cname),
        "-d",
        "-it",
        port_flags,
        mount_flags,
        env_flags,
        user_options_str,
        "--net=host",
        image,
        "bash",
    ]
    cmds.append(" ".join(docker_check + docker_run))

    return cmds


# Traceback (AssertionError)
ray up config/example_full.yaml
2020-06-08 01:13:10,526 INFO config.py:143 -- _configure_iam_role: Role not specified for head node, using arn:aws:iam::<redacted>:instance-profile/ray-autoscaler-v1
2020-06-08 01:13:11,089 INFO config.py:194 -- _configure_key_pair: KeyName not specified for nodes, using ray-autoscaler_us-west-2
2020-06-08 01:13:11,365 INFO config.py:235 -- _configure_subnet: SubnetIds not specified for head node, using [('subnet-<redacted>', 'us-west-2b'), ('subnet-<redacted>', 'us-west-2a')]
2020-06-08 01:13:11,366 INFO config.py:241 -- _configure_subnet: SubnetId not specified for workers, using [('subnet-<redacted>', 'us-west-2b'), ('subnet-<redacted>', 'us-west-2a')]
2020-06-08 01:13:11,725 INFO config.py:261 -- _configure_security_group: SecurityGroupIds not specified for head node, using ray-autoscaler-default (sg-<redacted>)
2020-06-08 01:13:11,725 INFO config.py:268 -- _configure_security_group: SecurityGroupIds not specified for workers, using ray-autoscaler-default (sg-<redacted>)
This will restart cluster services [y/N]: y
2020-06-08 01:13:15,214 INFO commands.py:238 -- get_or_create_head_node: Updating files on head node...
2020-06-08 01:13:15,215 INFO updater.py:379 -- NodeUpdater: i-<redacted>: Updating to <redacted>
2020-06-08 01:13:15,216 INFO updater.py:423 -- NodeUpdater: i-<redacted>: Waiting for remote shell...
2020-06-08 01:13:15,422 INFO log_timer.py:22 -- AWSNodeProvider: Set tag ray-node-status=waiting-for-ssh on ['i-<redacted>
Exception in thread Thread-2:
Traceback (most recent call last):
File "/usr/lib/python3.6/threading.py", line 916, in _bootstrap_inner
self.run()
File "/home/richard/improbable/ray/python/ray/autoscaler/updater.py", line 383, in run
self.do_update()
File "/home/richard/improbable/ray/python/ray/autoscaler/updater.py", line 450, in do_update
self.wait_ready(deadline)
File "/home/richard/improbable/ray/python/ray/autoscaler/updater.py", line 444, in wait_ready
assert False, "Unable to connect to node"
AssertionError: Unable to connect to node

2020-06-08 01:11:59,679 ERROR commands.py:304 -- get_or_create_head_node: Updating <redacted> failed
2020-06-08 01:11:59,701 INFO log_timer.py:22 -- AWSNodeProvider: Set tag ray-node-status=update-failed on ['i-<redacted>']  [LogTimer=333ms]

# Fixed code
def docker_start_cmds(user, image, mount, cname, user_options):
    cmds = []

    # create flags
    # ports for the redis, object manager, and tune client
    port_flags = " ".join(
        ["-p {port}:{port}".format(port=port) for port in ["6379", "8076", "4321"]]
    )
    mount_flags = " ".join(
        ["-v {src}:{dest}".format(src=k, dest=v) for k, v in mount.items()]
    )

    # for click, used in ray cli
    env_vars = {"LC_ALL": "C.UTF-8", "LANG": "C.UTF-8"}
    env_flags = " ".join(
        ["-e {name}={val}".format(name=k, val=v) for k, v in env_vars.items()]
    )

    user_options_str = " ".join(user_options)
    # docker run command
    docker_check = check_docker_running_cmd(cname) + " || "
    docker_run = [
        "docker",
        "run",
        "--rm",
        "--name {}".format(cname),
        "-d",
        "-it",
        port_flags,
        mount_flags,
        env_flags,
        user_options_str,
        "--net=host",
        image,
        "bash",
    ]
    cmds.append(docker_check + " ".join(docker_run))

    return cmds