check_home_assistant_state/check_home_assistant_state.py

406 lines
12 KiB
Python
Executable File

#!/usr/bin/env python3
"""A check plugin for Nagios/Icinga/etc. that queries Home Assistant for the current state of entities."""
import argparse
import dataclasses
import logging
import re
import sys
from urllib.parse import urljoin
from typing import Optional
from pathlib import Path
import requests
import nagiosplugin
_log = logging.getLogger("nagiosplugin")
class ScalarOrUnknownContext(nagiosplugin.ScalarContext):
"""
Same as a :class:`nagiosplugin.ScalarContext`, but returns UNKNOWN when the
value is not an int or float
"""
def evaluate(self, metric: nagiosplugin.Metric, resource: nagiosplugin.Resource):
if isinstance(metric.value, (int, float)):
return super().evaluate(metric, resource)
else:
return self.result_cls(
nagiosplugin.state.Unknown, "non-scalar value", metric
)
def performance(self, metric: nagiosplugin.Metric, resource: nagiosplugin.Resource):
if isinstance(metric.value, (int, float)):
return super().performance(metric, resource)
else:
return nagiosplugin.Performance(
metric.name,
"U",
metric.uom,
self.warning,
self.critical,
metric.min,
metric.max,
)
@dataclasses.dataclass
class Entities(nagiosplugin.Resource):
url: str
token: str
device_class: str
numeric: bool
filters: list[str]
attribute: Optional[str]
friendly_name: bool
ignore_missing: bool
min: Optional[float] = None
max: Optional[float] = None
def hass_get(self, endpoint: str) -> requests.Response:
headers = {
"Authorization": "Bearer " + self.token,
"Content-Type": "application/json",
}
r = requests.get(urljoin(self.url, endpoint), headers=headers)
if not r.ok:
raise Exception("Failed to query Home Assistant API: " + r.text)
return r.json()
def check_api(self):
message = self.hass_get("/api/").get("message")
if message != "API running.":
print("ERROR: " + message)
sys.exit(1)
else:
print("OK: " + message)
def probe(self):
response = self.hass_get("/api/states")
for state in response:
if state["attributes"].get("device_class") == self.device_class and all(
state["attributes"].get(k) == v for k, v in self.filters
):
if self.attribute is not None:
if (
self.ignore_missing
and self.attribute not in state["attributes"]
):
continue
else:
value = state["attributes"].get(
self.attribute, "missing attribute"
)
uom = None
else:
if self.numeric:
try:
value = float(state["state"])
except ValueError:
value = state["state"]
else:
value = state["state"]
uom = state["attributes"].get("unit_of_measurement")
if self.friendly_name:
name = (
state["attributes"]
.get("friendly_name", state["entity_id"])
.translate({ord(c): "_" for c in "'="})
)
else:
name = state["entity_id"]
yield nagiosplugin.Metric(
name,
value,
uom,
context=self.device_class,
min=self.min,
max=self.max,
)
class RegexContext(nagiosplugin.Context):
def __init__(
self,
name: str,
ok: str = None,
warning: str = None,
critical: str = None,
fmt_metric=None,
result_cls=nagiosplugin.Result,
):
super().__init__(name, fmt_metric=fmt_metric, result_cls=result_cls)
# '.^' should match nothing
self.ok = re.compile(ok or ".^")
self.warning = re.compile(warning or ".^")
self.critical = re.compile(critical or ".^")
def fmt_reason(self, regex: re.Pattern, metric: nagiosplugin.Metric) -> str:
return f"{metric.name} matched regex '{regex.pattern}' ({metric.value})"
def evaluate(self, metric: nagiosplugin.Metric, resource):
if self.critical.match(metric.value):
return self.result_cls(
nagiosplugin.Critical, self.fmt_reason(self.critical, metric), metric
)
elif self.warning.match(metric.value):
return self.result_cls(
nagiosplugin.Warn, self.fmt_reason(self.warning, metric), metric
)
elif self.ok.match(metric.value):
return self.result_cls(
nagiosplugin.Ok, self.fmt_reason(self.ok, metric), metric
)
else:
return self.result_cls(
nagiosplugin.Unknown,
f"{metric.name} did not match any defined patterns ({metric.value})",
metric,
)
def key_value(arg: str):
k, _, v = arg.partition("=")
return k, v
class Icinga2ConfAction(argparse.Action):
def __init__(
self,
option_strings,
dest=argparse.SUPPRESS,
default=argparse.SUPPRESS,
help="Generate conf file for icinga2 CheckCommand",
):
super().__init__(
option_strings=option_strings,
dest=dest,
default=default,
nargs=0,
help=help,
)
def _format_actions(
self,
param_prefix: str,
parser: argparse.ArgumentParser,
order: Optional[int] = None,
):
for action in parser._actions:
if action.dest in [self.dest, "help", "version"] or isinstance(
action, argparse._SubParsersAction
):
continue
arg_str = action.option_strings[-1]
icinga2_var = arg_str.lstrip("-").replace("-", "_")
print(f' "{arg_str}" = {{')
if action.required:
print(" required = true")
if isinstance(
action,
(
argparse._StoreConstAction,
argparse._CountAction,
argparse._AppendConstAction,
),
):
print(f' set_if = "${param_prefix}_{icinga2_var}$"')
else:
print(f' value = "${param_prefix}_{icinga2_var}$"')
print(f' description = "{action.help}"')
if order is not None:
print(f" order = {order}")
print(" }")
def __call__(
self, parser: argparse.ArgumentParser, namespace, values, option_string=None
):
filename = Path(__file__).absolute()
command_name = filename.stem.removeprefix("check_")
# FIXME: assumes that script will be in a subdirectory of PluginContribDir
command_path = filename.relative_to(filename.parents[1])
if parser._subparsers:
# TODO: this seems a bit more hacky than it needs to be
choices = parser._subparsers._group_actions[0].choices
for subname, subparser in choices.items():
print(f'object CheckCommand "{command_name}_{subname}" {{')
print(f' command = [ PluginContribDir + "/{command_path}" ]')
print(" arguments = {")
self._format_actions(command_name, parser, order=-2)
print(f' "{subname}" = {{')
print(" set_if = true")
print(" order = -1")
print(" }")
self._format_actions(f"{command_name}_{subname}", subparser)
print(" }\n}")
else:
print(f'object CheckCommand "{command_name}" {{')
print(f' command = [ PluginContribDir + "/{command_path}" ]')
print(" arguments = {")
self._format_actions(command_name, parser)
print(" }\n}")
parser.exit()
@nagiosplugin.guarded
def main():
argp = argparse.ArgumentParser(description=__doc__)
argp.add_argument("--version", action="version", version="0.2.0")
argp.add_argument("-v", "--verbose", action="count", default=0)
argp.add_argument("--make-icinga-conf", action=Icinga2ConfAction)
argp.add_argument(
"-t",
"--token",
required=True,
type=str,
help="token for Home Assistant REST API (see https://developers.home-assistant.io/docs/api/rest/)",
)
argp.add_argument(
"-u", "--url", required=True, type=str, help="URL for Home Assistant"
)
shared_parser = argparse.ArgumentParser(add_help=False)
common_args = shared_parser.add_argument_group(
"Common Arguments", "Arguments shared between metric types"
)
common_args.add_argument(
"-d",
"--device-class",
type=str,
required=True,
help="device class of entities to monitor",
)
common_args.add_argument(
"-a", "--attribute", type=str, help="check attribute instead of value"
)
common_args.add_argument(
"-f",
"--filter",
type=key_value,
default=[],
nargs="*",
help="filter by 'attribute=value' (may be specified multiple times)",
)
common_args.add_argument(
"--friendly",
action="store_true",
help="use friendly name, when available",
)
common_args.add_argument(
"--ignore-missing", action="store_true", help="Ignore missing attributes"
)
subparsers = argp.add_subparsers(
title="Query type", required=True, dest="subparser_name"
)
scalar_parser = subparsers.add_parser(
"scalar", help="Numeric metrics", parents=[shared_parser]
)
scalar_parser.add_argument(
"-w",
"--warning",
metavar="RANGE",
required=True,
help="return warning if value is outside %(metavar)s",
)
scalar_parser.add_argument(
"-c",
"--critical",
metavar="RANGE",
required=True,
help="return critical if value is outside %(metavar)s",
)
scalar_parser.add_argument(
"--min",
type=float,
help="min for performance data",
)
scalar_parser.add_argument(
"--max",
type=float,
help="max for performance data",
)
text_parser = subparsers.add_parser(
"text", help="Textual metrics", parents=[shared_parser]
)
text_parser.add_argument(
"-o",
"--ok",
metavar="REGEX",
help="return ok if value matches %(metavar)s",
)
text_parser.add_argument(
"-w",
"--warning",
metavar="REGEX",
help="return warning if value matches %(metavar)s",
)
text_parser.add_argument(
"-c",
"--critical",
metavar="REGEX",
help="return critical if value matches %(metavar)s",
)
args = argp.parse_args()
if args.subparser_name == "scalar":
check = nagiosplugin.Check(
Entities(
url=args.url,
token=args.token,
device_class=args.device_class,
numeric=True,
min=args.min,
max=args.max,
filters=args.filter,
attribute=args.attribute,
friendly_name=args.friendly,
ignore_missing=args.ignore_missing,
),
ScalarOrUnknownContext(args.device_class, args.warning, args.critical),
)
elif args.subparser_name == "text":
check = nagiosplugin.Check(
Entities(
url=args.url,
token=args.token,
device_class=args.device_class,
numeric=False,
filters=args.filter,
attribute=args.attribute,
friendly_name=args.friendly,
ignore_missing=args.ignore_missing,
),
RegexContext(args.device_class, args.ok, args.warning, args.critical),
)
check.main(args.verbose)
if __name__ == "__main__":
main()