# octavia.amphorae.backends.agent.api_server.util

# Source code for octavia.amphorae.backends.agent.api_server.util

    # Copyright 2015 Hewlett-Packard Development Company, L.P.
    #
    # Licensed under the Apache License, Version 2.0 (the "License"); you may
    # not use this file except in compliance with the License. You may obtain
    # a copy of the License at
    #
    # http://www.apache.org/licenses/LICENSE-2.0
    #
    # Unless required by applicable law or agreed to in writing, software
    # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
    # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
    # License for the specific language governing permissions and limitations
    #    under the License.

    import os
    import re
    import stat
    import subprocess
    import typing as tp

    import jinja2
    from oslo_config import cfg
    from oslo_log import log as logging

    from octavia.amphorae.backends.utils import ip_advertisement
    from octavia.amphorae.backends.utils import network_utils
    from octavia.common import constants as consts

    CONF = cfg.CONF
    LOG = logging.getLogger(__name__)

    FRONTEND_BACKEND_PATTERN = re.compile(r'\n(frontend|backend)\s+(\S+)\n')
    LISTENER_MODE_PATTERN = re.compile(r'^\s+mode\s+(.*)$', re.MULTILINE)
    TLS_CERT_PATTERN = re.compile(r'^\s+bind\s+\S+\s+ssl crt-list\s+(\S*)',
                                  re.MULTILINE)
    STATS_SOCKET_PATTERN = re.compile(r'stats socket\s+(\S+)')

    class ParsingError(Exception):
        pass

    def init_path(lb_id):
        return os.path.join(consts.SYSTEMD_DIR, f'haproxy-{lb_id}.service')

    def keepalived_lvs_dir():
        return os.path.join(CONF.haproxy_amphora.base_path, 'lvs')

    def keepalived_lvs_init_path(listener_id):
        return os.path.join(consts.SYSTEMD_DIR,
                            consts.KEEPALIVEDLVS_SYSTEMD %
                            str(listener_id))

    def keepalived_backend_check_script_dir():
        return os.path.join(CONF.haproxy_amphora.base_path, 'lvs/check/')

    def keepalived_backend_check_script_path():
        return os.path.join(keepalived_backend_check_script_dir(),
                            'udp_check.sh')

    def keepalived_lvs_pids_path(listener_id):
        pids_path = {}
        for file_ext in ['pid', 'vrrp.pid', 'check.pid']:
            pids_path[file_ext] = (
                os.path.join(CONF.haproxy_amphora.base_path,
                             f"lvs/octavia-keepalivedlvs-{str(listener_id)}."
                             f"{file_ext}"))
        return pids_path['pid'], pids_path['vrrp.pid'], pids_path['check.pid']

    def keepalived_lvs_cfg_path(listener_id):
        return os.path.join(CONF.haproxy_amphora.base_path,
                            f"lvs/octavia-keepalivedlvs-{str(listener_id)}.conf")

    def haproxy_dir(lb_id):
        return os.path.join(CONF.haproxy_amphora.base_path, lb_id)

    def pid_path(lb_id):
        return os.path.join(haproxy_dir(lb_id), lb_id + '.pid')

    def config_path(lb_id):
        return os.path.join(haproxy_dir(lb_id), 'haproxy.cfg')

    def state_file_path(lb_id):
        return os.path.join(haproxy_dir(lb_id), 'servers-state')

    def get_haproxy_pid(lb_id):
        with open(pid_path(lb_id), encoding='utf-8') as f:
            return f.readline().rstrip()

    def get_keepalivedlvs_pid(listener_id):
        pid_file = keepalived_lvs_pids_path(listener_id)[0]
        with open(pid_file, encoding='utf-8') as f:
            return f.readline().rstrip()

    def haproxy_sock_path(lb_id):
        return os.path.join(CONF.haproxy_amphora.base_path, lb_id + '.sock')

    def haproxy_check_script_path():
        return os.path.join(keepalived_check_scripts_dir(),
                            'haproxy_check_script.sh')

    def keepalived_dir():
        return os.path.join(CONF.haproxy_amphora.base_path, 'vrrp')

    def keepalived_init_path():
        return os.path.join(consts.SYSTEMD_DIR, consts.KEEPALIVED_SYSTEMD)

    def keepalived_pid_path():
        return os.path.join(CONF.haproxy_amphora.base_path,
                            'vrrp/octavia-keepalived.pid')

    def keepalived_cfg_path():
        return os.path.join(CONF.haproxy_amphora.base_path,
                            'vrrp/octavia-keepalived.conf')

    def keepalived_log_path():
        return os.path.join(CONF.haproxy_amphora.base_path,
                            'vrrp/octavia-keepalived.log')

    def keepalived_check_scripts_dir():
        return os.path.join(CONF.haproxy_amphora.base_path,
                            'vrrp/check_scripts')

    def keepalived_check_script_path():
        return os.path.join(CONF.haproxy_amphora.base_path,
                            'vrrp/check_script.sh')

    def get_listeners():
        """Get Listeners

        :returns: An array with the ids of all listeners, e.g. ['123', '456', ...]
                  or [] if no listeners exist
        """
        listeners = []
        for lb_id in get_loadbalancers():
            listeners_on_lb = parse_haproxy_file(lb_id)[1]
            listeners.extend(list(listeners_on_lb.keys()))
        return listeners

    def get_loadbalancers():
        """Get Load balancers

        :returns: An array with the uuids of all load balancers,
                  e.g. ['123', '456', ...] or [] if no loadbalancers exist
        """
        if os.path.exists(CONF.haproxy_amphora.base_path):
            return [f for f in os.listdir(CONF.haproxy_amphora.base_path)
                    if os.path.exists(config_path(f))]
        return []

    def is_lb_running(lb_id):
        return os.path.exists(pid_path(lb_id)) and os.path.exists(
            os.path.join('/proc', get_haproxy_pid(lb_id)))

    def get_lvs_listeners():
        result = []
        if os.path.exists(keepalived_lvs_dir()):
            for f in os.listdir(keepalived_lvs_dir()):
                if f.endswith('.conf'):
                    prefix = f.split('.')[0]
                    if re.search("octavia-keepalivedlvs-", prefix):
                        result.append(f.split(
                            'octavia-keepalivedlvs-')[1].split('.')[0])
        return result

    def is_lvs_listener_running(listener_id):
        pid_file = keepalived_lvs_pids_path(listener_id)[0]
        return os.path.exists(pid_file) and os.path.exists(
            os.path.join('/proc', get_keepalivedlvs_pid(listener_id)))

    def install_netns_systemd_service():
        flags = os.O_WRONLY | os.O_CREAT | os.O_TRUNC
        # mode 00644
        mode = stat.S_IRUSR | stat.S_IWUSR | stat.S_IRGRP | stat.S_IROTH

        # TODO(bcafarel): implement this for other init systems
        # netns handling depends on a separate unit file
        netns_path = os.path.join(consts.SYSTEMD_DIR,
                                  consts.AMP_NETNS_SVC_PREFIX + '.service')

        jinja_env = jinja2.Environment(
            autoescape=True, loader=jinja2.FileSystemLoader(os.path.dirname(
                os.path.realpath(__file__)
            ) + consts.AGENT_API_TEMPLATES))

        if not os.path.exists(netns_path):
            with os.fdopen(os.open(netns_path, flags, mode), 'w') as text_file:
                text = jinja_env.get_template(
                    consts.AMP_NETNS_SVC_PREFIX + '.systemd.j2').render(
                        amphora_nsname=consts.AMPHORA_NAMESPACE)
                text_file.write(text)

    def run_systemctl_command(command, service, raise_error=True):
        cmd = f"systemctl {command} {service}"
        try:
            subprocess.check_output(cmd.split(), stderr=subprocess.STDOUT,
                                    encoding='utf-8')
        except subprocess.CalledProcessError as e:
            LOG.debug("Failed to %(cmd)s %(srvc)s service: "
                      "%(err)s %(out)s", {'cmd': command, 'srvc': service,
                                          'err': e, 'out': e.output})
            if raise_error:
                raise

    def get_backend_for_lb_object(object_id):
        """Returns the backend for a listener.

        If the listener is a TCP based listener return 'HAPROXY'.
        If the listener is a UDP or SCTP based listener return 'LVS'
        If the listener is not identifiable, return None.

        :param listener_id: The ID of the listener to identify.
        :returns: HAPROXY_BACKEND, LVS_BACKEND or None
        """
        if os.path.exists(config_path(object_id)):
            return consts.HAPROXY_BACKEND
        if os.path.exists(keepalived_lvs_cfg_path(object_id)):
            return consts.LVS_BACKEND
        return None

    def parse_haproxy_file(lb_id):
        with open(config_path(lb_id), encoding='utf-8') as file:
            cfg = file.read()

            listeners = {}

            m = FRONTEND_BACKEND_PATTERN.split(cfg)
            last_token = None
            last_id = None
            for section in m:
                if last_token is None:
                    # We aren't in a section yet, see if this line starts one
                    if section == 'frontend':
                        last_token = section
                elif last_token == 'frontend':
                    # We're in a frontend section, save the id for later
                    last_token = last_token + "_id"
                    last_id = section
                elif last_token == 'frontend_id':
                    # We're in a frontend section and already have the id
                    # Look for the mode
                    mode_matcher = LISTENER_MODE_PATTERN.search(section)
                    if not mode_matcher:
                        raise ParsingError()
                    listeners[last_id] = {
                        'mode': mode_matcher.group(1).upper(),
                    }
                    # Now see if this is a TLS frontend
                    tls_matcher = TLS_CERT_PATTERN.search(section)
                    if tls_matcher:
                        # TODO(rm_work): Can't we have terminated tcp?
                        listeners[last_id]['mode'] = 'TERMINATED_HTTPS'
                        listeners[last_id]['ssl_crt'] = tls_matcher.group(1)
                    # Clear out the token and id and start over
                    last_token = last_id = None

            m = STATS_SOCKET_PATTERN.search(cfg)
            if not m:
                raise ParsingError()
            stats_socket = m.group(1)

            return stats_socket, listeners

    def vrrp_check_script_update(lb_id, action):
        os.makedirs(keepalived_dir(), exist_ok=True)
        os.makedirs(keepalived_check_scripts_dir(), exist_ok=True)

        lb_ids = get_loadbalancers()
        lvs_ids = get_lvs_listeners()
        # If no LBs are found, so make sure keepalived thinks haproxy is down.
        if not lb_ids:
            if not lvs_ids:
                with open(haproxy_check_script_path(),
                          'w', encoding='utf-8') as text_file:
                    text_file.write('exit 1')
            else:
                try:
                    LOG.debug("Attempting to remove old haproxy check script...")
                    os.remove(haproxy_check_script_path())
                    LOG.debug("Finished removing old haproxy check script.")
                except FileNotFoundError:
                    LOG.debug("No haproxy check script to remove.")
            return
        if action == consts.AMP_ACTION_STOP:
            lb_ids.remove(lb_id)
        args = []
        for lbid in lb_ids:
            args.append(haproxy_sock_path(lbid))

        cmd = f"haproxy-vrrp-check {' '.join(args)}; exit $?"
        with open(haproxy_check_script_path(), 'w', encoding='utf-8') as text_file:
            text_file.write(cmd)

    def get_haproxy_vip_addresses(lb_id):
        """Get the VIP addresses for a load balancer.

        :param lb_id: The load balancer ID to get VIP addresses from.
        :returns: List of VIP addresses (IPv4 and IPv6)
        """
        vips = []
        with open(config_path(lb_id), encoding='utf-8') as file:
            for line in file:
                current_line = line.strip()
                if current_line.startswith('bind'):
                    for section in current_line.split(' '):
                        # We will always have a port assigned per the template.
                        if ':' in section:
                            if ',' in section:
                                addr_port = section.rstrip(',')
                                vips.append(addr_port.rpartition(':')[0])
                            else:
                                vips.append(section.rpartition(':')[0])
                                break
        return vips

    def get_lvs_vip_addresses(listener_id: str) -> list[str]:
        """Get the VIP addresses for a LVS load balancer.

        :param listener_id: The listener ID to get VIP addresses from.
        :returns: List of VIP addresses (IPv4 and IPv6)
        """
        vips = []
        # Extract the VIP addresses from keepalived configuration
        # Format is
        # virtual_server_group ipv<n>-group {
        #     vip_address1 port1
        #     vip_address2 port2
        # }
        # it can be repeated in case of dual-stack LBs
        with open(keepalived_lvs_cfg_path(listener_id), encoding='utf-8') as file:
            vsg_section = False
            for line in file:
                current_line = line.strip()
                if vsg_section:
                    if current_line.startswith('}'):
                        vsg_section = False
                    else:
                        vip_address = current_line.split(' ')[0]
                        vips.append(vip_address)
                elif line.startswith('virtual_server_group '):
                    vsg_section = True
        return vips

    def send_vip_advertisements(lb_id: tp.Optional[str] = None,
                                listener_id: tp.Optional[str] = None):
        """Sends address advertisements for each load balancer VIP.

        This method will send either GARP (IPv4) or neighbor advertisements (IPv6)
        for the VIP addresses on a load balancer.

        :param lb_id: The load balancer ID to send advertisements for.
        :returns: None
        """
        try:
            if lb_id:
                vips = get_haproxy_vip_addresses(lb_id)
            else:
                vips = get_lvs_vip_addresses(listener_id)

            for vip in vips:
                interface = network_utils.get_interface_name(
                    vip, net_ns=consts.AMPHORA_NAMESPACE)
                ip_advertisement.send_ip_advertisement(
                    interface, vip, net_ns=consts.AMPHORA_NAMESPACE)
        except Exception as e:
            LOG.debug('Send VIP advertisement failed due to :%s. '
                      'This amphora may not be the MASTER. Ignoring.', str(e))

    def send_member_advertisements(fixed_ips: tp.Iterable[tp.Dict[str, str]]):
        """Sends advertisements for each fixed_ip of a list

        This method will send either GARP (IPv4) or neighbor advertisements (IPv6)
        for the addresses of the subnets of the members.

        :param fixed_ips: a list of dicts that contain 'ip_address' elements
        :returns: None
        """
        try:
            for fixed_ip in fixed_ips:
                ip_address = fixed_ip[consts.IP_ADDRESS]
                interface = network_utils.get_interface_name(
                    ip_address, net_ns=consts.AMPHORA_NAMESPACE)
                ip_advertisement.send_ip_advertisement(
                    interface, ip_address, net_ns=consts.AMPHORA_NAMESPACE)
        except Exception as e:
            LOG.debug('Send member advertisement failed due to: %s', str(e))

this page last updated: 2026-03-10 18:02:42

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