import logging
import os
import re
+import shlex
from subprocess import CalledProcessError
import tempfile
+import time
import uuid
from juju.client import client
+import n2vc.exceptions
+import paramiko
import asyncio
arches = [
return await self._ssh(
"{} /bin/bash {}".format("sudo" if root else "", tmpFile)
)
+
+
+class SSHProvisioner:
+ """Provision a manually created machine via SSH."""
+
+ def __init__(self, user, host, private_key_path, log=None):
+
+ self.host = host
+ self.user = user
+ self.private_key_path = private_key_path
+
+ if log:
+ self.log = log
+ else:
+ self.log = logging.getLogger(__name__)
+
+ def _get_ssh_client(self, host=None, user=None, private_key_path=None):
+ """Return a connected Paramiko ssh object.
+
+ :param str host: The host to connect to.
+ :param str user: The user to connect as.
+ :param str key: The private key to authenticate with.
+
+ :return: object: A paramiko.SSHClient
+ :raises: :class:`paramiko.ssh_exception.SSHException` if the
+ connection failed
+ """
+
+ if not host:
+ host = self.host
+
+ if not user:
+ user = self.user
+
+ if not private_key_path:
+ private_key_path = self.private_key_path
+
+ ssh = paramiko.SSHClient()
+ ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
+
+ pkey = None
+
+ # Read the private key into a paramiko.RSAKey
+ if os.path.exists(private_key_path):
+ with open(private_key_path, "r") as f:
+ pkey = paramiko.RSAKey.from_private_key(f)
+
+ #######################################################################
+ # There is a bug in some versions of OpenSSH 4.3 (CentOS/RHEL5) where #
+ # the server may not send the SSH_MSG_USERAUTH_BANNER message except #
+ # when responding to an auth_none request. For example, paramiko will #
+ # attempt to use password authentication when a password is set, but #
+ # the server could deny that, instead requesting keyboard-interactive.#
+ # The hack to workaround this is to attempt a reconnect, which will #
+ # receive the right banner, and authentication can proceed. See the #
+ # following for more info: #
+ # https://github.com/paramiko/paramiko/issues/432 #
+ # https://github.com/paramiko/paramiko/pull/438 #
+ #######################################################################
+
+ retry = 10
+ attempts = 0
+ delay = 15
+ while attempts <= retry:
+ try:
+ attempts += 1
+
+ # Attempt to establish a SSH connection
+ ssh.connect(
+ host,
+ port=22,
+ username=user,
+ pkey=pkey,
+ # allow_agent=False,
+ # look_for_keys=False,
+ )
+ break
+ except paramiko.ssh_exception.SSHException as e:
+ if "Error reading SSH protocol banner" == str(e):
+ # Once more, with feeling
+ ssh.connect(host, port=22, username=user, pkey=pkey)
+ else:
+ # Reraise the original exception
+ self.log.debug("Unhandled exception caught: {}".format(e))
+ raise e
+ except Exception as e:
+ if "Unable to connect to port" in str(e):
+ self.log.debug(
+ "Waiting for VM to boot, sleeping {} seconds".format(delay)
+ )
+ if attempts > retry:
+ raise e
+ else:
+ time.sleep(delay)
+ # Slowly back off the retry
+ delay += 15
+ else:
+ self.log.debug(e)
+ raise e
+ return ssh
+
+ def _run_command(self, ssh, cmd, pty=True):
+ """Run a command remotely via SSH.
+
+ :param object ssh: The SSHClient
+ :param str cmd: The command to execute
+ :param list cmd: The `shlex.split` command to execute
+ :param bool pty: Whether to allocate a pty
+
+ :return: tuple: The stdout and stderr of the command execution
+ :raises: :class:`CalledProcessError` if the command fails
+ """
+
+ if isinstance(cmd, str):
+ cmd = shlex.split(cmd)
+
+ if type(cmd) is not list:
+ cmd = [cmd]
+
+ cmds = " ".join(cmd)
+ _, stdout, stderr = ssh.exec_command(cmds, get_pty=pty)
+ retcode = stdout.channel.recv_exit_status()
+
+ if retcode > 0:
+ output = stderr.read().strip()
+ raise CalledProcessError(returncode=retcode, cmd=cmd, output=output)
+ return (
+ stdout.read().decode("utf-8").strip(),
+ stderr.read().decode("utf-8").strip(),
+ )
+
+ def _init_ubuntu_user(self):
+ """Initialize the ubuntu user.
+
+ :return: bool: If the initialization was successful
+ :raises: :class:`paramiko.ssh_exception.AuthenticationException`
+ if the authentication fails
+ """
+ ssh = None
+ try:
+ # Run w/o allocating a pty, so we fail if sudo prompts for a passwd
+ ssh = self._get_ssh_client()
+ self._run_command(ssh, "sudo -n true", pty=False)
+ except paramiko.ssh_exception.AuthenticationException:
+ raise n2vc.exceptions.AuthenticationFailed(self.user)
+ except paramiko.ssh_exception.NoValidConnectionsError:
+ raise n2vc.exceptions.NoRouteToHost(self.host)
+ finally:
+ if ssh:
+ ssh.close()
+
+ # Infer the public key
+ public_key_path = "{}.pub".format(self.private_key_path)
+
+ if not os.path.exists(public_key_path):
+ raise FileNotFoundError(
+ "Public key '{}' doesn't exist.".format(public_key_path)
+ )
+
+ with open(public_key_path, "r") as f:
+ public_key = f.readline()
+
+ script = INITIALIZE_UBUNTU_SCRIPT.format(public_key)
+
+ try:
+ ssh = self._get_ssh_client()
+
+ self._run_command(
+ ssh, ["sudo", "/bin/bash -c " + shlex.quote(script)], pty=True
+ )
+ except paramiko.ssh_exception.AuthenticationException as e:
+ raise e
+ finally:
+ ssh.close()
+
+ return True
+
+ def _detect_hardware_and_os(self, ssh):
+ """Detect the target hardware capabilities and OS series.
+
+ :param object ssh: The SSHClient
+ :return: str: A raw string containing OS and hardware information.
+ """
+
+ info = {
+ "series": "",
+ "arch": "",
+ "cpu-cores": "",
+ "mem": "",
+ }
+
+ stdout, _ = self._run_command(
+ ssh, ["sudo", "/bin/bash -c " + shlex.quote(DETECTION_SCRIPT)], pty=True,
+ )
+
+ lines = stdout.split("\n")
+
+ # Remove extraneous line if DNS resolution of hostname famils
+ # i.e. sudo: unable to resolve host test-1-mgmtvm-1: Connection timed out
+ if "unable to resolve host" in lines[0]:
+ lines = lines[1:]
+
+ info["series"] = lines[0].strip()
+ info["arch"] = normalize_arch(lines[1].strip())
+
+ memKb = re.split(r"\s+", lines[2])[1]
+
+ # Convert megabytes -> kilobytes
+ info["mem"] = round(int(memKb) / 1024)
+
+ # Detect available CPUs
+ recorded = {}
+ for line in lines[3:]:
+ physical_id = ""
+
+ if line.find("physical id") == 0:
+ physical_id = line.split(":")[1].strip()
+ elif line.find("cpu cores") == 0:
+ cores = line.split(":")[1].strip()
+
+ if physical_id not in recorded.keys():
+ info["cpu-cores"] += cores
+ recorded[physical_id] = True
+
+ return info
+
+ def provision_machine(self):
+ """Perform the initial provisioning of the target machine.
+
+ :return: bool: The client.AddMachineParams
+ :raises: :class:`paramiko.ssh_exception.AuthenticationException`
+ if the upload fails
+ """
+ params = client.AddMachineParams()
+
+ if self._init_ubuntu_user():
+ try:
+ ssh = self._get_ssh_client()
+
+ hw = self._detect_hardware_and_os(ssh)
+ params.series = hw["series"]
+ params.instance_id = "manual:{}".format(self.host)
+ params.nonce = "manual:{}:{}".format(
+ self.host, str(uuid.uuid4()),
+ ) # a nop for Juju w/manual machines
+ params.hardware_characteristics = {
+ "arch": hw["arch"],
+ "mem": int(hw["mem"]),
+ "cpu-cores": int(hw["cpu-cores"]),
+ }
+ params.addresses = [
+ {"value": self.host, "type": "ipv4", "scope": "public"}
+ ]
+
+ except paramiko.ssh_exception.AuthenticationException as e:
+ raise e
+ finally:
+ ssh.close()
+
+ return params
+
+ async def install_agent(self, connection, nonce, machine_id, api):
+ """
+ :param object connection: Connection to Juju API
+ :param str nonce: The nonce machine specification
+ :param str machine_id: The id assigned to the machine
+
+ :return: bool: If the initialization was successful
+ """
+ # The path where the Juju agent should be installed.
+ data_dir = "/var/lib/juju"
+
+ # Disabling this prevents `apt-get update` from running initially, so
+ # charms will fail to deploy
+ disable_package_commands = False
+
+ client_facade = client.ClientFacade.from_connection(connection)
+ results = await client_facade.ProvisioningScript(
+ data_dir=data_dir,
+ disable_package_commands=disable_package_commands,
+ machine_id=machine_id,
+ nonce=nonce,
+ )
+
+ """Get the IP of the controller
+
+ Parse the provisioning script, looking for the first apiaddress.
+
+ Example:
+ apiaddresses:
+ - 10.195.8.2:17070
+ - 127.0.0.1:17070
+ - '[::1]:17070'
+ """
+ m = re.search(r"apiaddresses:\n- (\d+\.\d+\.\d+\.\d+):17070", results.script)
+ apiaddress = m.group(1)
+
+ """Add IP Table rule
+
+ In order to route the traffic to the private ip of the Juju controller
+ we use a DNAT rule to tell the machine that the destination for the
+ private address is the public address of the machine where the Juju
+ controller is running in LXD. That machine will have a complimentary
+ iptables rule, routing traffic to the appropriate LXD container.
+ """
+
+ script = IPTABLES_SCRIPT.format(apiaddress, api)
+
+ # Run this in a retry loop, because dpkg may be running and cause the
+ # script to fail.
+ retry = 10
+ attempts = 0
+ delay = 15
+
+ while attempts <= retry:
+ try:
+ attempts += 1
+
+ self._run_configure_script(script)
+ break
+ except Exception as e:
+ self.log.debug("Waiting for dpkg, sleeping {} seconds".format(delay))
+ if attempts > retry:
+ raise e
+ else:
+ time.sleep(delay)
+ # Slowly back off the retry
+ delay += 15
+
+ # self.log.debug("Running configure script")
+ self._run_configure_script(results.script)
+ # self.log.debug("Configure script finished")
+
+ def _run_configure_script(self, script: str):
+ """Run the script to install the Juju agent on the target machine.
+
+ :param str script: The script returned by the ProvisioningScript API
+ :raises: :class:`paramiko.ssh_exception.AuthenticationException`
+ if the upload fails
+ """
+ _, tmpFile = tempfile.mkstemp()
+ with open(tmpFile, "w") as f:
+ f.write(script)
+ try:
+ # get ssh client
+ ssh = self._get_ssh_client(user="ubuntu",)
+
+ # copy the local copy of the script to the remote machine
+ sftp = paramiko.SFTPClient.from_transport(ssh.get_transport())
+ sftp.put(
+ tmpFile, tmpFile,
+ )
+
+ # run the provisioning script
+ self._run_command(
+ ssh, "sudo /bin/bash {}".format(tmpFile),
+ )
+
+ except paramiko.ssh_exception.AuthenticationException as e:
+ raise e
+ finally:
+ os.remove(tmpFile)
+ ssh.close()