520 lines
23 KiB
Python
520 lines
23 KiB
Python
# Copyright 2024 Red Hat, Inc.
|
|
#
|
|
# 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.
|
|
#
|
|
from observabilityclient import prometheus_client
|
|
from oslo_config import cfg
|
|
from oslo_log import log
|
|
import re
|
|
from watcher._i18n import _
|
|
from watcher.common import exception
|
|
from watcher.decision_engine.datasources import base
|
|
|
|
CONF = cfg.CONF
|
|
LOG = log.getLogger(__name__)
|
|
|
|
|
|
class PrometheusHelper(base.DataSourceBase):
|
|
"""PrometheusHelper class for retrieving metrics from Prometheus server
|
|
|
|
This class implements the DataSourceBase to allow Watcher to query
|
|
Prometheus as a data source for metrics.
|
|
"""
|
|
|
|
NAME = 'prometheus'
|
|
METRIC_MAP = dict(host_cpu_usage='node_cpu_seconds_total',
|
|
host_ram_usage='node_memory_MemAvailable_bytes',
|
|
host_outlet_temp=None,
|
|
host_inlet_temp=None,
|
|
host_airflow=None,
|
|
host_power=None,
|
|
instance_cpu_usage='ceilometer_cpu',
|
|
instance_ram_usage='ceilometer_memory_usage',
|
|
instance_ram_allocated='instance.memory',
|
|
instance_l3_cache_usage=None,
|
|
instance_root_disk_size='instance.disk',
|
|
)
|
|
AGGREGATES_MAP = dict(mean='avg', max='max', min='min', count='avg')
|
|
|
|
def __init__(self):
|
|
"""Initialise the PrometheusHelper
|
|
|
|
The prometheus helper uses the PrometheusAPIClient provided by
|
|
python-observabilityclient.
|
|
The prometheus_fqdn_labels contains a list the values contained in
|
|
the fqdn_label in the Prometheus instance. When making queries to
|
|
Prometheus we use the fqdn_label to specify the node for which
|
|
metrics are to be retrieved.
|
|
host, port and fqdn_label come from watcher_client
|
|
config. The prometheus_fqdn_label allows override of the required label
|
|
in Prometheus scrape configs that specifies each target's fqdn.
|
|
"""
|
|
self.prometheus = self._setup_prometheus_client()
|
|
self.prometheus_fqdn_label = (
|
|
CONF.prometheus_client.fqdn_label
|
|
)
|
|
self.prometheus_fqdn_labels = (
|
|
self._build_prometheus_fqdn_labels()
|
|
)
|
|
self.prometheus_host_instance_map = (
|
|
self._build_prometheus_host_instance_map()
|
|
)
|
|
|
|
def _setup_prometheus_client(self):
|
|
"""Initialise the prometheus client with config options
|
|
|
|
Use the prometheus_client options in watcher.conf to setup
|
|
the PrometheusAPIClient client object and return it.
|
|
:raises watcher.common.exception.MissingParameter if
|
|
prometheus host or port is not set in the watcher.conf
|
|
under the [prometheus_client] section.
|
|
:raises watcher.common.exception.InvalidParameter if
|
|
the prometheus host or port have invalid format.
|
|
"""
|
|
def _validate_host_port(host, port):
|
|
if len(host) > 255:
|
|
return (False, "hostname is too long: '%s'" % host)
|
|
if host[-1] == '.':
|
|
host = host[:-1]
|
|
legal_hostname = re.compile(
|
|
"(?!-)[a-z0-9-]{1,63}(?<!-)$", re.IGNORECASE)
|
|
if not all(legal_hostname.match(host_part)
|
|
for host_part in host.split(".")):
|
|
return (False, "hostname '%s' failed regex match " % host)
|
|
try:
|
|
assert bool(1 <= int(port) <= 65535)
|
|
except (AssertionError, ValueError):
|
|
return (False, "missing or invalid port number '%s' "
|
|
% port)
|
|
return (True, "all good")
|
|
|
|
_host = CONF.prometheus_client.host
|
|
_port = CONF.prometheus_client.port
|
|
if (not _host or not _port):
|
|
raise exception.MissingParameter(
|
|
message=(_(
|
|
"prometheus host and port must be set in watcher.conf "
|
|
"under the [prometheus_client] section. Can't initialise "
|
|
"the datasource without valid host and port."))
|
|
)
|
|
validated, reason = _validate_host_port(_host, _port)
|
|
if (not validated):
|
|
raise exception.InvalidParameter(
|
|
message=(_(
|
|
"A valid prometheus host and port are required. The #"
|
|
"values found in watcher.conf are '%(host)s' '%(port)s'. "
|
|
"This fails validation for the following reason: "
|
|
"%(reason)s.")
|
|
% {'host': _host, 'port': _port, 'reason': reason})
|
|
)
|
|
the_client = prometheus_client.PrometheusAPIClient(
|
|
"%s:%s" % (_host, _port))
|
|
|
|
# check if tls options or basic_auth options are set and use them
|
|
prometheus_user = CONF.prometheus_client.username
|
|
prometheus_pass = CONF.prometheus_client.password
|
|
prometheus_ca_cert = CONF.prometheus_client.cafile
|
|
prometheus_client_cert = CONF.prometheus_client.certfile
|
|
prometheus_client_key = CONF.prometheus_client.keyfile
|
|
if (prometheus_ca_cert):
|
|
the_client.set_ca_cert(prometheus_ca_cert)
|
|
if (prometheus_client_cert and prometheus_client_key):
|
|
the_client.set_client_cert(
|
|
prometheus_client_cert, prometheus_client_key)
|
|
if (prometheus_user and prometheus_pass):
|
|
the_client.set_basic_auth(prometheus_user, prometheus_pass)
|
|
|
|
return the_client
|
|
|
|
def _build_prometheus_fqdn_labels(self):
|
|
"""Build the list of fqdn_label values to be used in host queries
|
|
|
|
Watcher knows nodes by their hostname. In Prometheus however the
|
|
scrape targets (also known as 'instances') are specified by I.P.
|
|
(or hostname) and port number and fqdn is stored in a custom 'fqdn'
|
|
label added to Prometheus scrape_configs. Operators can use a
|
|
different custom label instead by setting the prometheus_fqdn_label
|
|
config option under the prometheus_client section of watcher config.
|
|
The built prometheus_fqdn_labels is created with the full list
|
|
of values of the prometheus_fqdn_label label in Prometheus. This will
|
|
be used to create a map of hostname<-->fqdn and to identify if a target
|
|
exist in prometheus for the compute nodes before sending the query.
|
|
:return a set of values of the fqdn label. For example:
|
|
{'foo.example.com', 'bar.example.com'}
|
|
{'foo', 'bar'}
|
|
"""
|
|
prometheus_targets = self.prometheus._get(
|
|
"targets?state=active")['data']['activeTargets']
|
|
# >>> prometheus_targets[0]['labels']
|
|
# {'fqdn': 'marios-env-again.controlplane.domain',
|
|
# 'instance': 'localhost:9100', 'job': 'node'}
|
|
fqdn_instance_labels = set()
|
|
for target in prometheus_targets:
|
|
if target.get('labels', {}).get(self.prometheus_fqdn_label):
|
|
fqdn_instance_labels.add(
|
|
target['labels'].get(self.prometheus_fqdn_label))
|
|
|
|
if not fqdn_instance_labels:
|
|
LOG.error(
|
|
"Could not create fqdn labels list from Prometheus "
|
|
"targets config. Prometheus returned the following: %s",
|
|
prometheus_targets
|
|
)
|
|
return set()
|
|
return fqdn_instance_labels
|
|
|
|
def _build_prometheus_host_instance_map(self):
|
|
"""Build the hostname<-->instance_label mapping needed for queries
|
|
|
|
The prometheus_fqdn_labels has the fully qualified domain name
|
|
for hosts. This will create a duplicate map containing only the host
|
|
name part. Depending on the watcher node.hostname either the
|
|
fqdn_instance_labels or the host_instance_map will be used to resolve
|
|
the correct prometheus fqdn_label for queries. In the event the
|
|
fqdn_instance_labels elements are not valid fqdn (for example it has
|
|
hostnames, not fqdn) the host_instance_map cannot be created and
|
|
an empty dictionary is returned with a warning logged.
|
|
:return a dict mapping hostname to instance label. For example:
|
|
{'foo': 'foo.example.com', 'bar': 'bar.example.com'}
|
|
"""
|
|
if not self.prometheus_fqdn_labels:
|
|
LOG.error("Cannot build host_instance_map without "
|
|
"fqdn_instance_labels")
|
|
return {}
|
|
host_instance_map = {
|
|
host: fqdn for (host, fqdn) in (
|
|
(fqdn.split('.')[0], fqdn)
|
|
for fqdn in self.prometheus_fqdn_labels
|
|
if '.' in fqdn
|
|
)
|
|
}
|
|
if not host_instance_map:
|
|
LOG.warning("Creating empty host instance map. Are the keys "
|
|
"in prometheus_fqdn_labels valid fqdn?")
|
|
return {}
|
|
return host_instance_map
|
|
|
|
def _resolve_prometheus_instance_label(self, node_name):
|
|
"""Resolve the prometheus instance label to use in queries
|
|
|
|
Given the watcher node.hostname, resolve the prometheus instance
|
|
label for use in queries, first trying the fqdn_instance_labels and
|
|
then the host_instance_map (watcher.node_name can be fqdn or hostname).
|
|
If the name is not resolved after the first attempt, rebuild the fqdn
|
|
and host instance maps and try again. This allows for new hosts added
|
|
after the initialisation of the fqdn_instance_labels.
|
|
:param node_name: the watcher node.hostname
|
|
:return String for the prometheus instance label and None if not found
|
|
"""
|
|
def _query_maps(node):
|
|
if node in self.prometheus_fqdn_labels:
|
|
return node
|
|
else:
|
|
return self.prometheus_host_instance_map.get(node, None)
|
|
|
|
instance_label = _query_maps(node_name)
|
|
# refresh the fqdn and host instance maps and retry
|
|
if not instance_label:
|
|
self.prometheus_fqdn_labels = (
|
|
self._build_prometheus_fqdn_labels()
|
|
)
|
|
self.prometheus_host_instance_map = (
|
|
self._build_prometheus_host_instance_map()
|
|
)
|
|
instance_label = _query_maps(node_name)
|
|
|
|
if not instance_label:
|
|
LOG.error("Cannot query prometheus without instance label. "
|
|
"Could not resolve %s", node_name)
|
|
return None
|
|
return instance_label
|
|
|
|
def _resolve_prometheus_aggregate(self, watcher_aggregate, meter):
|
|
"""Resolve the prometheus aggregate using self.AGGREGATES_MAP
|
|
|
|
This uses the AGGREGATES_MAP to resolve the correct prometheus
|
|
aggregate to use in queries, from the given watcher aggregate
|
|
"""
|
|
if watcher_aggregate == 'count':
|
|
LOG.warning('Prometheus data source does not currently support '
|
|
' the count aggregate. Proceeding with mean (avg).')
|
|
promql_aggregate = self.AGGREGATES_MAP.get(watcher_aggregate)
|
|
if not promql_aggregate:
|
|
raise exception.InvalidParameter(
|
|
message=(_("Unknown Watcher aggregate %s. This does not "
|
|
"resolve to any valid prometheus query aggregate.")
|
|
% watcher_aggregate)
|
|
)
|
|
return promql_aggregate
|
|
|
|
def _build_prometheus_query(self, aggregate, meter, instance_label,
|
|
period, resource=None):
|
|
"""Build and return the prometheus query string with the given args
|
|
|
|
This function builds and returns the string query that will be sent
|
|
to the Prometheus server /query endpoint. For host cpu usage we use:
|
|
|
|
100 - (avg by (fqdn)(rate(node_cpu_seconds_total{mode='idle',
|
|
fqdn='some_host'}[300s])) * 100)
|
|
|
|
so using prometheus rate function over the specified period, we average
|
|
per instance (all cpus) idle time and then 'everything else' is cpu
|
|
usage time.
|
|
|
|
For host memory usage we use:
|
|
|
|
(node_memory_MemTotal_bytes{instance='the_host'} -
|
|
avg_over_time(
|
|
node_memory_MemAvailable_bytes{instance='the_host'}[300s]))
|
|
/ 1024
|
|
|
|
So we take total and subtract available memory to determine
|
|
how much is in use. We use the prometheus xxx_over_time functions
|
|
avg/max/min depending on the aggregate with the specified time period.
|
|
|
|
:param aggregate: one of the values of self.AGGREGATES_MAP
|
|
:param meter: the name of the Prometheus meter to use
|
|
:param instance_label: the Prometheus instance label (scrape target).
|
|
:param period: the period in seconds for which to query
|
|
:param resource: the resource object for which metrics are requested
|
|
:return: a String containing the Prometheus query
|
|
:raises watcher.common.exception.InvalidParameter if params are None
|
|
:raises watcher.common.exception.InvalidParameter if meter is not
|
|
known or currently supported (prometheus meter name).
|
|
"""
|
|
query_args = None
|
|
uuid_label_key = CONF.prometheus_client.instance_uuid_label
|
|
if (meter is None or aggregate is None or instance_label is None or
|
|
period is None):
|
|
raise exception.InvalidParameter(
|
|
message=(_(
|
|
"Cannot build prometheus query without args. "
|
|
"You provided: meter %(mtr)s, aggregate %(agg)s, "
|
|
"instance_label %(inst)s, period %(prd)s")
|
|
% {'mtr': meter, 'agg': aggregate,
|
|
'inst': instance_label, 'prd': period})
|
|
)
|
|
|
|
if meter == 'node_cpu_seconds_total':
|
|
query_args = (
|
|
"100 - (%(agg)s by (%(label)s)(rate(%(meter)s"
|
|
"{mode='idle',%(label)s='%(label_value)s'}[%(period)ss])) "
|
|
"* 100)"
|
|
% {'label': self.prometheus_fqdn_label,
|
|
'label_value': instance_label, 'agg': aggregate,
|
|
'meter': meter, 'period': period}
|
|
)
|
|
elif meter == 'node_memory_MemAvailable_bytes':
|
|
# Prometheus metric is in B and we need to return KB
|
|
query_args = (
|
|
"(node_memory_MemTotal_bytes{%(label)s='%(label_value)s'} "
|
|
"- %(agg)s_over_time(%(meter)s{%(label)s='%(label_value)s'}"
|
|
"[%(period)ss])) / 1024"
|
|
% {'label': self.prometheus_fqdn_label,
|
|
'label_value': instance_label, 'agg': aggregate,
|
|
'meter': meter, 'period': period}
|
|
)
|
|
elif meter == 'ceilometer_memory_usage':
|
|
query_args = (
|
|
"%s_over_time(%s{%s='%s'}[%ss])" %
|
|
(aggregate, meter, uuid_label_key, instance_label, period)
|
|
)
|
|
elif meter == 'ceilometer_cpu':
|
|
# We are converting the total cumulative cpu time (ns) to cpu usage
|
|
# percentage so we need to divide between the number of vcpus.
|
|
# As this is a percentage metric, we set a max level of 100. It has
|
|
# been observed in very high usage cases, prometheus reporting
|
|
# values higher that 100 what can lead to unexpected behaviors.
|
|
vcpus = resource.vcpus
|
|
if not vcpus:
|
|
LOG.warning(
|
|
"instance vcpu count not set for instance %s, assuming 1",
|
|
instance_label
|
|
)
|
|
vcpus = 1
|
|
query_args = (
|
|
"clamp_max((%(agg)s by (%(label)s)"
|
|
"(rate(%(meter)s{%(label)s='%(label_value)s'}[%(period)ss]))"
|
|
"/10e+8) *(100/%(vcpus)s), 100)"
|
|
% {'label': uuid_label_key, 'label_value': instance_label,
|
|
'agg': aggregate, 'meter': meter, 'period': period,
|
|
'vcpus': vcpus}
|
|
)
|
|
else:
|
|
raise exception.InvalidParameter(
|
|
message=(_("Cannot process prometheus meter %s") % meter)
|
|
)
|
|
|
|
return query_args
|
|
|
|
def check_availability(self):
|
|
"""check if Prometheus server is available for queries
|
|
|
|
Performs HTTP get on the prometheus API /status/runtimeinfo endpoint.
|
|
The prometheus_client will raise a PrometheuAPIClientError if the
|
|
call is unsuccessful, which is caught here and a warning logged.
|
|
"""
|
|
try:
|
|
self.prometheus._get("status/runtimeinfo")
|
|
except prometheus_client.PrometheusAPIClientError:
|
|
LOG.warning(
|
|
"check_availability raised PrometheusAPIClientError. "
|
|
"Is Prometheus server down?"
|
|
)
|
|
return 'not available'
|
|
return 'available'
|
|
|
|
def list_metrics(self):
|
|
"""Fetch all prometheus metrics from api/v1/label/__name__/values
|
|
|
|
The prometheus_client will raise a PrometheuAPIClientError if the
|
|
call is unsuccessful, which is caught here and a warning logged.
|
|
"""
|
|
try:
|
|
response = self.prometheus._get("label/__name__/values")
|
|
except prometheus_client.PrometheusAPIClientError:
|
|
LOG.warning(
|
|
"list_metrics raised PrometheusAPIClientError. Is Prometheus"
|
|
"server down?"
|
|
)
|
|
return set()
|
|
return set(response['data'])
|
|
|
|
def statistic_aggregation(self, resource=None, resource_type=None,
|
|
meter_name=None, period=300, aggregate='mean',
|
|
granularity=300):
|
|
|
|
meter = self._get_meter(meter_name)
|
|
query_args = ''
|
|
instance_label = ''
|
|
|
|
# For instance resource type, the datasource expects the uuid of the
|
|
# instance to be assigned to a label in the prometheus metrics, with a
|
|
# specific key value.
|
|
if resource_type == 'compute_node':
|
|
instance_label = self._resolve_prometheus_instance_label(
|
|
resource.hostname)
|
|
elif resource_type == 'instance':
|
|
instance_label = resource.uuid
|
|
# For ram_allocated and root_disk size metrics there are no valid
|
|
# values in the prometheus backend store. We rely in the values
|
|
# provided in the vms inventory.
|
|
if meter == 'instance.memory':
|
|
return float(resource.memory)
|
|
elif meter == 'instance.disk':
|
|
return float(resource.disk)
|
|
else:
|
|
LOG.warning(
|
|
"Prometheus data source does not currently support "
|
|
"resource_type %s", resource_type
|
|
)
|
|
return None
|
|
|
|
promql_aggregate = self._resolve_prometheus_aggregate(aggregate, meter)
|
|
query_args = self._build_prometheus_query(
|
|
promql_aggregate, meter, instance_label, period, resource
|
|
)
|
|
if not query_args:
|
|
LOG.error("Cannot proceed without valid prometheus query")
|
|
return None
|
|
|
|
result = self.query_retry(
|
|
self.prometheus.query, query_args,
|
|
ignored_exc=prometheus_client.PrometheusAPIClientError,
|
|
)
|
|
|
|
return float(result[0].value) if result else None
|
|
|
|
def statistic_series(self, resource=None, resource_type=None,
|
|
meter_name=None, start_time=None, end_time=None,
|
|
granularity=300):
|
|
raise NotImplementedError(
|
|
_('Prometheus helper currently does not support statistic_series. '
|
|
'This can be considered for future enhancement.'))
|
|
|
|
def _invert_max_min_aggregate(self, agg):
|
|
"""Invert max and min for node/host metric queries from node-exporter
|
|
|
|
because we query for 'idle'/'unused' cpu and memory.
|
|
For Watcher 'max cpu used' we query for prometheus 'min idle time'.
|
|
For Watcher 'max memory used' we retrieve min 'unused'/'available'
|
|
memory from Prometheus. This internal function is used exclusively
|
|
by get_host_cpu_usage and get_host_ram_usage.
|
|
:param agg: the metric collection aggregate
|
|
:return: a String aggregate
|
|
|
|
"""
|
|
if agg == 'max':
|
|
return 'min'
|
|
elif agg == 'min':
|
|
return 'max'
|
|
return agg
|
|
|
|
def get_host_cpu_usage(self, resource, period=300,
|
|
aggregate="mean", granularity=None):
|
|
"""Query prometheus for node_cpu_seconds_total
|
|
|
|
This calculates the host cpu usage and returns it as a percentage
|
|
The calculation is made by using the cpu 'idle' time, per
|
|
instance (so all CPUs are included). For example the query looks like
|
|
(100 - (avg by (fqdn)(rate(node_cpu_seconds_total
|
|
{mode='idle',fqdn='compute1.example.com'}[300s])) * 100))
|
|
"""
|
|
aggregate = self._invert_max_min_aggregate(aggregate)
|
|
cpu_usage = self.statistic_aggregation(
|
|
resource, 'compute_node',
|
|
'host_cpu_usage', period=period,
|
|
granularity=granularity, aggregate=aggregate)
|
|
return float(cpu_usage) if cpu_usage else None
|
|
|
|
def get_host_ram_usage(self, resource, period=300,
|
|
aggregate="mean", granularity=None):
|
|
aggregate = self._invert_max_min_aggregate(aggregate)
|
|
ram_usage = self.statistic_aggregation(
|
|
resource, 'compute_node',
|
|
'host_ram_usage', period=period,
|
|
granularity=granularity, aggregate=aggregate)
|
|
return float(ram_usage) if ram_usage else None
|
|
|
|
def get_instance_ram_usage(self, resource, period=300,
|
|
aggregate="mean", granularity=None):
|
|
ram_usage = self.statistic_aggregation(
|
|
resource, 'instance',
|
|
'instance_ram_usage', period=period,
|
|
granularity=granularity, aggregate=aggregate)
|
|
return ram_usage
|
|
|
|
def get_instance_cpu_usage(self, resource, period=300,
|
|
aggregate="mean", granularity=None):
|
|
cpu_usage = self.statistic_aggregation(
|
|
resource, 'instance',
|
|
'instance_cpu_usage', period=period,
|
|
granularity=granularity, aggregate=aggregate)
|
|
return cpu_usage
|
|
|
|
def get_instance_ram_allocated(self, resource, period=300,
|
|
aggregate="mean", granularity=None):
|
|
ram_allocated = self.statistic_aggregation(
|
|
resource, 'instance',
|
|
'instance_ram_allocated', period=period,
|
|
granularity=granularity, aggregate=aggregate)
|
|
return ram_allocated
|
|
|
|
def get_instance_root_disk_size(self, resource, period=300,
|
|
aggregate="mean", granularity=None):
|
|
root_disk_size = self.statistic_aggregation(
|
|
resource, 'instance',
|
|
'instance_root_disk_size', period=period,
|
|
granularity=granularity, aggregate=aggregate)
|
|
return root_disk_size
|