[Kimchi-devel] [PATCH 3/4] Live migration: model changes for the new features

From: Daniel Henrique Barboza <dhbarboza82(a)gmail.com&gt; - added extra pre migration checks to ensure that the migration process will not fail due to a predictable error - added the capability of set up a password-less root login to a remote host if given a valid user/password. Signed-off-by: Daniel Henrique Barboza <dhbarboza82(a)gmail.com&gt; --- src/wok/plugins/kimchi/model/vms.py | 177 +++++++++++++++++++++++++++++++++--- 1 file changed, 166 insertions(+), 11 deletions(-) diff --git a/src/wok/plugins/kimchi/model/vms.py b/src/wok/plugins/kimchi/model/vms.py index c98558c..48e99a3 100644 --- a/src/wok/plugins/kimchi/model/vms.py +++ b/src/wok/plugins/kimchi/model/vms.py @@ -21,8 +21,11 @@ import copy import libvirt import lxml.etree as ET import os +import paramiko +import platform import random import socket +import subprocess import string import threading import time @@ -1323,15 +1326,156 @@ class VMModel(object): if remote_host in ['localhost', '127.0.0.1', hostname]: raise OperationFailed("KCHVM0055E", {'host': remote_host}) - def _check_if_password_less_login_enabled(self, remote_host, user): - username_host = "%s@%s" % (user, remote_host) + def _check_if_migrating_same_arch_hypervisor(self, remote_host, + user='root'): + remote_conn = None + try: + remote_conn = self._get_remote_libvirt_conn( + remote_host, + user + ) + source_hyp = self.conn.get().getType() + dest_hyp = remote_conn.getType() + if source_hyp != dest_hyp: + raise OperationFailed( + "KCHVM0065E", + { + 'host': remote_host, + 'srchyp': source_hyp, + 'desthyp': dest_hyp + } + ) + source_arch = self.conn.get().getInfo()[0] + dest_arch = remote_conn.getInfo()[0] + if source_arch != dest_arch: + raise OperationFailed( + "KCHVM0064E", + { + 'host': remote_host, + 'srcarch': source_arch, + 'destarch': dest_arch + } + ) + except Exception, e: + raise OperationFailed("KCHVM0066E", {'error': e.message}) + + finally: + if remote_conn: + remote_conn.close() + + def _check_ppc64_subcores_per_core(self, remote_host, user): + """ + Output expected from command-line: + + $ ppc64_cpu --subcores-per-core + Subcores per core: N + """ + + def _get_local_ppc64_subpercore(): + local_cmd = ['ppc64_cpu', '--subcores-per-core'] + out, err, returncode = run_command(local_cmd, 5, silent=True) + if returncode != 0: + return None + local_sub_per_core = out.strip()[-1] + return local_sub_per_core + + def _get_remote_ppc64_subpercore(remote_host, user): + username_host = "%s@%s" % ('root', remote_host) + ssh_cmd = ['ssh', '-oNumberOfPasswordPrompts=0', + '-oStrictHostKeyChecking=no', username_host, + 'ppc64_cpu', '--subcores-per-core'] + out, err, returncode = run_command(ssh_cmd, 5, silent=True) + if returncode != 0: + return None + remote_sub_per_core = out.strip()[-1] + return remote_sub_per_core + + local_sub_per_core = _get_local_ppc64_subpercore() + if local_sub_per_core is None: + return + + remote_sub_per_core = _get_remote_ppc64_subpercore(remote_host, user) + + if local_sub_per_core != remote_sub_per_core: + raise OperationFailed("KCHVM0067E", {'host': remote_host}) + + def _check_if_password_less_login_enabled(self, remote_host, + user, password): + username_host = "%s@%s" % ('root', remote_host) ssh_cmd = ['ssh', '-oNumberOfPasswordPrompts=0', '-oStrictHostKeyChecking=no', username_host, 'echo', 'hello'] stdout, stderr, returncode = run_command(ssh_cmd, 5, silent=True) if returncode != 0: - raise OperationFailed("KCHVM0056E", - {'host': remote_host, 'user': user}) + if password is None: + raise OperationFailed("KCHVM0056E", + {'host': remote_host, 'user': 'root'}) + else: + self._set_password_less_login(remote_host, user, password) + + def _set_password_less_login(self, remote_host, user, passwd): + id_rsa_file = "/root/.ssh/id_rsa.pub" + ssh_port = 22 + ssh_client = None + + def create_root_ssh_key_if_required(): + if not os.path.isfile(id_rsa_file): + + with open("/dev/zero") as zero_input: + cmd = ['ssh-keygen', '-q', '-N', ''] + proc = subprocess.Popen( + cmd, + stdin=zero_input, + stdout=open(os.devnull, 'wb') + ) + out, err = proc.communicate() + if not os.path.isfile(id_rsa_file): + raise OperationFailed("KCHVM0070E") + + def read_id_rsa_pub_file(): + data = None + with open(id_rsa_file, "r") as id_file: + data = id_file.read() + return data + + def get_ssh_client(remote_host, user, passwd): + ssh_client = paramiko.SSHClient() + ssh_client.set_missing_host_key_policy(paramiko.AutoAddPolicy()) + ssh_client.connect(remote_host, ssh_port, username=user, + password=passwd, timeout=4) + return ssh_client + + def append_id_rsa_to_remote_authorized_keys(ssh_client, id_rsa_data): + sftp_client = ssh_client.open_sftp() + + file_handler = sftp_client.file( + '/root/.ssh/authorized_keys', + mode='a', + bufsize=1 + ) + file_handler.write(id_rsa_data) + file_handler.flush() + file_handler.close() + + sftp_client.close() + + try: + create_root_ssh_key_if_required() + id_rsa_data = read_id_rsa_pub_file() + ssh_client = get_ssh_client(remote_host, user, passwd) + append_id_rsa_to_remote_authorized_keys( + ssh_client, + id_rsa_data + ) + except Exception, e: + raise OperationFailed( + "KCHVM0068E", + {'host': remote_host, 'user': user, 'error': e.message} + ) + + finally: + if ssh_client: + ssh_client.close() def _get_remote_libvirt_conn(self, remote_host, user='root', transport='ssh'): @@ -1339,12 +1483,20 @@ class VMModel(object): # TODO: verify why LibvirtConnection(dest_uri) does not work here return libvirt.open(dest_uri) - def migration_pre_check(self, remote_host, user): + def migration_pre_check(self, remote_host, user, password): self._check_if_host_not_localhost(remote_host) - self._check_if_password_less_login_enabled(remote_host, user) + self._check_if_password_less_login_enabled( + remote_host, + user, + password + ) + self._check_if_migrating_same_arch_hypervisor(remote_host, user) + + if platform.machine() in ['ppc64', 'ppc64le']: + self._check_ppc64_subcores_per_core(remote_host, user) def _check_if_path_exists_in_remote_host(self, path, remote_host, user): - username_host = "%s@%s" % (user, remote_host) + username_host = "%s@%s" % ('root', remote_host) cmd = ['ssh', '-oStrictHostKeyChecking=no', username_host, 'test', '-f', path] _, _, returncode = run_command(cmd, 5, silent=True) @@ -1365,7 +1517,7 @@ class VMModel(object): return False def _create_remote_path(self, path, remote_host, user): - username_host = "%s@%s" % (user, remote_host) + username_host = "%s@%s" % ('root', remote_host) cmd = ['ssh', '-oStrictHostKeyChecking=no', username_host, 'touch', path] _, _, returncode = run_command(cmd, 5, silent=True) @@ -1387,7 +1539,7 @@ class VMModel(object): ) def _create_remote_disk(self, disk_info, remote_host, user): - username_host = "%s@%s" % (user, remote_host) + username_host = "%s@%s" % ('root', remote_host) disk_fmt = disk_info.get('format') disk_path = disk_info.get('path') disk_size = self._get_img_size(disk_path) @@ -1424,11 +1576,14 @@ class VMModel(object): user ) - def migrate(self, name, remote_host, user='root'): + def migrate(self, name, remote_host, user=None, password=None): name = name.decode('utf-8') remote_host = remote_host.decode('utf-8') - self.migration_pre_check(remote_host, user) + if user is None: + user = 'root' + + self.migration_pre_check(remote_host, user, password) dest_conn = self._get_remote_libvirt_conn(remote_host) non_shared = self._check_if_nonshared_migration( -- 2.4.3