From 1d01da5d9916d97ef463ba61a36b3f98f8911419 Mon Sep 17 00:00:00 2001 From: James Falcon Date: Wed, 27 Oct 2021 09:43:34 -0500 Subject: Add "install hotplug" module (SC-476) (#1069) This commit removes automatically installing udev rules for hotplug and adds a module to install them instead. Automatically including the udev rules and checking if hotplug was enabled consumed too many resources in certain circumstances. Moving the rules to a module ensures we don't spend extra extra cycles on hotplug if hotplug functionality isn't desired. LP: #1946003 --- cloudinit/cmd/devel/hotplug_hook.py | 5 +- cloudinit/config/cc_install_hotplug.py | 136 +++++++++++++++++++++++++++++++++ cloudinit/stages.py | 95 +++++++++++++---------- 3 files changed, 193 insertions(+), 43 deletions(-) create mode 100644 cloudinit/config/cc_install_hotplug.py (limited to 'cloudinit') diff --git a/cloudinit/cmd/devel/hotplug_hook.py b/cloudinit/cmd/devel/hotplug_hook.py index d4f0547e..f6f36a00 100644 --- a/cloudinit/cmd/devel/hotplug_hook.py +++ b/cloudinit/cmd/devel/hotplug_hook.py @@ -8,6 +8,7 @@ import time from cloudinit import log from cloudinit import reporting +from cloudinit import stages from cloudinit.event import EventScope, EventType from cloudinit.net import activators, read_sys_net_safe from cloudinit.net.network_state import parse_net_config_data @@ -164,7 +165,9 @@ def is_enabled(hotplug_init, subsystem): subsystem) ) from e - return hotplug_init.update_event_enabled( + return stages.update_event_enabled( + datasource=hotplug_init.datasource, + cfg=hotplug_init.cfg, event_source_type=EventType.HOTPLUG, scope=scope ) diff --git a/cloudinit/config/cc_install_hotplug.py b/cloudinit/config/cc_install_hotplug.py new file mode 100644 index 00000000..d6b2a2df --- /dev/null +++ b/cloudinit/config/cc_install_hotplug.py @@ -0,0 +1,136 @@ +# This file is part of cloud-init. See LICENSE file for license information. +"""Install hotplug udev rules if supported and enabled""" +import os +from textwrap import dedent + +from cloudinit import util +from cloudinit import subp +from cloudinit import stages +from cloudinit.config.schema import get_schema_doc, validate_cloudconfig_schema +from cloudinit.distros import ALL_DISTROS +from cloudinit.event import EventType, EventScope +from cloudinit.settings import PER_INSTANCE + + +frequency = PER_INSTANCE +distros = [ALL_DISTROS] + +schema = { + "id": "cc_install_hotplug", + "name": "Install Hotplug", + "title": "Install hotplug if supported and enabled", + "description": dedent("""\ + This module will install the udev rules to enable hotplug if + supported by the datasource and enabled in the userdata. The udev + rules will be installed as + ``/etc/udev/rules.d/10-cloud-init-hook-hotplug.rules``. + + When hotplug is enabled, newly added network devices will be added + to the system by cloud-init. After udev detects the event, + cloud-init will referesh the instance metadata from the datasource, + detect the device in the updated metadata, then apply the updated + network configuration. + + Currently supported datasources: Openstack, EC2 + """), + "distros": distros, + "examples": [ + dedent("""\ + # Enable hotplug of network devices + updates: + network: + when: ["hotplug"] + """), + dedent("""\ + # Enable network hotplug alongside boot event + updates: + network: + when: ["boot", "hotplug"] + """), + ], + "frequency": frequency, + "type": "object", + "properties": { + "updates": { + "type": "object", + "additionalProperties": False, + "properties": { + "network": { + "type": "object", + "required": ["when"], + "additionalProperties": False, + "properties": { + "when": { + "type": "array", + "additionalProperties": False, + "items": { + "type": "string", + "additionalProperties": False, + "enum": [ + "boot-new-instance", + "boot-legacy", + "boot", + "hotplug", + ] + } + } + } + } + } + } + } +} + +__doc__ = get_schema_doc(schema) + + +HOTPLUG_UDEV_PATH = "/etc/udev/rules.d/10-cloud-init-hook-hotplug.rules" +HOTPLUG_UDEV_RULES = """\ +# Installed by cloud-init due to network hotplug userdata +ACTION!="add|remove", GOTO="cloudinit_end" +LABEL="cloudinit_hook" +SUBSYSTEM=="net", RUN+="/usr/lib/cloud-init/hook-hotplug" +LABEL="cloudinit_end" +""" + + +def handle(_name, cfg, cloud, log, _args): + validate_cloudconfig_schema(cfg, schema) + network_hotplug_enabled = ( + 'updates' in cfg and + 'network' in cfg['updates'] and + 'when' in cfg['updates']['network'] and + 'hotplug' in cfg['updates']['network']['when'] + ) + hotplug_supported = EventType.HOTPLUG in ( + cloud.datasource.get_supported_events( + [EventType.HOTPLUG]).get(EventScope.NETWORK, set()) + ) + hotplug_enabled = stages.update_event_enabled( + datasource=cloud.datasource, + cfg=cfg, + event_source_type=EventType.HOTPLUG, + scope=EventScope.NETWORK, + ) + if not (hotplug_supported and hotplug_enabled): + if os.path.exists(HOTPLUG_UDEV_PATH): + log.debug("Uninstalling hotplug, not enabled") + util.del_file(HOTPLUG_UDEV_PATH) + subp.subp(["udevadm", "control", "--reload-rules"]) + elif network_hotplug_enabled: + log.warning( + "Hotplug is unsupported by current datasource. " + "Udev rules will NOT be installed." + ) + else: + log.debug("Skipping hotplug install, not enabled") + return + if not subp.which("udevadm"): + log.debug("Skipping hotplug install, udevadm not found") + return + + util.write_file( + filename=HOTPLUG_UDEV_PATH, + content=HOTPLUG_UDEV_RULES, + ) + subp.subp(["udevadm", "control", "--reload-rules"]) diff --git a/cloudinit/stages.py b/cloudinit/stages.py index 80aa9f5e..731b2982 100644 --- a/cloudinit/stages.py +++ b/cloudinit/stages.py @@ -49,6 +49,54 @@ NULL_DATA_SOURCE = None NO_PREVIOUS_INSTANCE_ID = "NO_PREVIOUS_INSTANCE_ID" +def update_event_enabled( + datasource: sources.DataSource, + cfg: dict, + event_source_type: EventType, + scope: EventScope = None +) -> bool: + """Determine if a particular EventType is enabled. + + For the `event_source_type` passed in, check whether this EventType + is enabled in the `updates` section of the userdata. If `updates` + is not enabled in userdata, check if defined as one of the + `default_events` on the datasource. `scope` may be used to + narrow the check to a particular `EventScope`. + + Note that on first boot, userdata may NOT be available yet. In this + case, we only have the data source's `default_update_events`, + so an event that should be enabled in userdata may be denied. + """ + default_events = datasource.default_update_events # type: Dict[EventScope, Set[EventType]] # noqa: E501 + user_events = userdata_to_events(cfg.get('updates', {})) # type: Dict[EventScope, Set[EventType]] # noqa: E501 + # A value in the first will override a value in the second + allowed = util.mergemanydict([ + copy.deepcopy(user_events), + copy.deepcopy(default_events), + ]) + LOG.debug('Allowed events: %s', allowed) + + if not scope: + scopes = allowed.keys() + else: + scopes = [scope] + scope_values = [s.value for s in scopes] + + for evt_scope in scopes: + if event_source_type in allowed.get(evt_scope, []): + LOG.debug( + 'Event Allowed: scope=%s EventType=%s', + evt_scope.value, event_source_type + ) + return True + + LOG.debug( + 'Event Denied: scopes=%s EventType=%s', + scope_values, event_source_type + ) + return False + + class Init(object): def __init__(self, ds_deps=None, reporter=None): if ds_deps is not None: @@ -715,46 +763,6 @@ class Init(object): return (self.distro.generate_fallback_config(), NetworkConfigSource.fallback) - def update_event_enabled( - self, event_source_type: EventType, scope: EventScope = None - ) -> bool: - """Determine if a particular EventType is enabled. - - For the `event_source_type` passed in, check whether this EventType - is enabled in the `updates` section of the userdata. If `updates` - is not enabled in userdata, check if defined as one of the - `default_events` on the datasource. `scope` may be used to - narrow the check to a particular `EventScope`. - - Note that on first boot, userdata may NOT be available yet. In this - case, we only have the data source's `default_update_events`, - so an event that should be enabled in userdata may be denied. - """ - default_events = self.datasource.default_update_events # type: Dict[EventScope, Set[EventType]] # noqa: E501 - user_events = userdata_to_events(self.cfg.get('updates', {})) # type: Dict[EventScope, Set[EventType]] # noqa: E501 - # A value in the first will override a value in the second - allowed = util.mergemanydict([ - copy.deepcopy(user_events), - copy.deepcopy(default_events), - ]) - LOG.debug('Allowed events: %s', allowed) - - if not scope: - scopes = allowed.keys() - else: - scopes = [scope] - scope_values = [s.value for s in scopes] - - for evt_scope in scopes: - if event_source_type in allowed.get(evt_scope, []): - LOG.debug('Event Allowed: scope=%s EventType=%s', - evt_scope.value, event_source_type) - return True - - LOG.debug('Event Denied: scopes=%s EventType=%s', - scope_values, event_source_type) - return False - def _apply_netcfg_names(self, netcfg): try: LOG.debug("applying net config names for %s", netcfg) @@ -784,8 +792,11 @@ class Init(object): return def event_enabled_and_metadata_updated(event_type): - return self.update_event_enabled( - event_type, scope=EventScope.NETWORK + return update_event_enabled( + datasource=self.datasource, + cfg=self.cfg, + event_source_type=event_type, + scope=EventScope.NETWORK ) and self.datasource.update_metadata_if_supported([event_type]) def should_run_on_boot_event(): -- cgit v1.2.3