diff --git a/lib/charms/prometheus_k8s/v0/prometheus_scrape.py b/lib/charms/prometheus_k8s/v0/prometheus_scrape.py index 13ae0c4..72c3fe7 100644 --- a/lib/charms/prometheus_k8s/v0/prometheus_scrape.py +++ b/lib/charms/prometheus_k8s/v0/prometheus_scrape.py @@ -18,13 +18,6 @@ Source code can be found on GitHub at: https://github.com/canonical/prometheus-k8s-operator/tree/main/lib/charms/prometheus_k8s -## Dependencies - -Using this library requires you to fetch the juju_topology library from -[observability-libs](https://charmhub.io/observability-libs/libraries/juju_topology). - -`charmcraft fetch-lib charms.observability_libs.v0.juju_topology` - ## Provider Library Usage This Prometheus charm interacts with its scrape targets using its @@ -343,12 +336,11 @@ def _on_scrape_targets_changed(self, event): from collections import defaultdict from pathlib import Path from typing import Any, Callable, Dict, List, Optional, Tuple, Union -from urllib.error import HTTPError, URLError from urllib.parse import urlparse -from urllib.request import urlopen import yaml -from charms.observability_libs.v0.juju_topology import JujuTopology +from cosl import JujuTopology +from cosl.rules import AlertRules from ops.charm import CharmBase, RelationRole from ops.framework import ( BoundEvent, @@ -370,7 +362,9 @@ def _on_scrape_targets_changed(self, event): # Increment this PATCH version before using `charmcraft publish-lib` or reset # to 0 if you are raising the major API version -LIBPATCH = 34 +LIBPATCH = 45 + +PYDEPS = ["cosl"] logger = logging.getLogger(__name__) @@ -391,6 +385,8 @@ def _on_scrape_targets_changed(self, event): "scheme", "basic_auth", "tls_config", + "authorization", + "params", } DEFAULT_JOB = { "metrics_path": "/metrics", @@ -601,15 +597,22 @@ def render_alertmanager_static_configs(alertmanagers: List[str]): # Create a mapping from paths to netlocs # Group alertmanager targets into a dictionary of lists: # {path: [netloc1, netloc2]} - paths = defaultdict(list) # type: Dict[str, List[str]] + paths = defaultdict(list) # type: Dict[Tuple[str, str], List[str]] for parsed in map(urlparse, sanitized): path = parsed.path or "/" - paths[path].append(parsed.netloc) + paths[(parsed.scheme, path)].append(parsed.netloc) return { "alertmanagers": [ - {"path_prefix": path_prefix, "static_configs": [{"targets": netlocs}]} - for path_prefix, netlocs in paths.items() + { + # For https we still do not render a `tls_config` section because + # certs are expected to be made available by the charm via the + # `update-ca-certificates` mechanism. + "scheme": scheme, + "path_prefix": path_prefix, + "static_configs": [{"targets": netlocs}], + } + for (scheme, path_prefix), netlocs in paths.items() ] } @@ -715,13 +718,12 @@ def _type_convert_stored(obj): """Convert Stored* to their appropriate types, recursively.""" if isinstance(obj, StoredList): return list(map(_type_convert_stored, obj)) - elif isinstance(obj, StoredDict): + if isinstance(obj, StoredDict): rdict = {} # type: Dict[Any, Any] for k in obj.keys(): rdict[k] = _type_convert_stored(obj[k]) return rdict - else: - return obj + return obj def _validate_relation_by_interface_and_direction( @@ -763,7 +765,7 @@ def _validate_relation_by_interface_and_direction( actual_relation_interface = relation.interface_name if actual_relation_interface != expected_relation_interface: raise RelationInterfaceMismatchError( - relation_name, expected_relation_interface, actual_relation_interface + relation_name, expected_relation_interface, actual_relation_interface or "None" ) if expected_relation_role == RelationRole.provides: @@ -831,206 +833,6 @@ def _is_single_alert_rule_format(rules_dict: dict) -> bool: return set(rules_dict) >= {"alert", "expr"} -class AlertRules: - """Utility class for amalgamating prometheus alert rule files and injecting juju topology. - - An `AlertRules` object supports aggregating alert rules from files and directories in both - official and single rule file formats using the `add_path()` method. All the alert rules - read are annotated with Juju topology labels and amalgamated into a single data structure - in the form of a Python dictionary using the `as_dict()` method. Such a dictionary can be - easily dumped into JSON format and exchanged over relation data. The dictionary can also - be dumped into YAML format and written directly into an alert rules file that is read by - Prometheus. Note that multiple `AlertRules` objects must not be written into the same file, - since Prometheus allows only a single list of alert rule groups per alert rules file. - - The official Prometheus format is a YAML file conforming to the Prometheus documentation - (https://prometheus.io/docs/prometheus/latest/configuration/alerting_rules/). - The custom single rule format is a subsection of the official YAML, having a single alert - rule, effectively "one alert per file". - """ - - # This class uses the following terminology for the various parts of a rule file: - # - alert rules file: the entire groups[] yaml, including the "groups:" key. - # - alert groups (plural): the list of groups[] (a list, i.e. no "groups:" key) - it is a list - # of dictionaries that have the "name" and "rules" keys. - # - alert group (singular): a single dictionary that has the "name" and "rules" keys. - # - alert rules (plural): all the alerts in a given alert group - a list of dictionaries with - # the "alert" and "expr" keys. - # - alert rule (singular): a single dictionary that has the "alert" and "expr" keys. - - def __init__(self, topology: Optional[JujuTopology] = None): - """Build and alert rule object. - - Args: - topology: an optional `JujuTopology` instance that is used to annotate all alert rules. - """ - self.topology = topology - self.tool = CosTool(None) - self.alert_groups = [] # type: List[dict] - - def _from_file(self, root_path: Path, file_path: Path) -> List[dict]: - """Read a rules file from path, injecting juju topology. - - Args: - root_path: full path to the root rules folder (used only for generating group name) - file_path: full path to a *.rule file. - - Returns: - A list of dictionaries representing the rules file, if file is valid (the structure is - formed by `yaml.safe_load` of the file); an empty list otherwise. - """ - with file_path.open() as rf: - # Load a list of rules from file then add labels and filters - try: - rule_file = yaml.safe_load(rf) - - except Exception as e: - logger.error("Failed to read alert rules from %s: %s", file_path.name, e) - return [] - - if not rule_file: - logger.warning("Empty rules file: %s", file_path.name) - return [] - if not isinstance(rule_file, dict): - logger.error("Invalid rules file (must be a dict): %s", file_path.name) - return [] - if _is_official_alert_rule_format(rule_file): - alert_groups = rule_file["groups"] - elif _is_single_alert_rule_format(rule_file): - # convert to list of alert groups - # group name is made up from the file name - alert_groups = [{"name": file_path.stem, "rules": [rule_file]}] - else: - # invalid/unsupported - logger.error("Invalid rules file: %s", file_path.name) - return [] - - # update rules with additional metadata - for alert_group in alert_groups: - # update group name with topology and sub-path - alert_group["name"] = self._group_name( - str(root_path), - str(file_path), - alert_group["name"], - ) - - # add "juju_" topology labels - for alert_rule in alert_group["rules"]: - if "labels" not in alert_rule: - alert_rule["labels"] = {} - - if self.topology: - alert_rule["labels"].update(self.topology.label_matcher_dict) - # insert juju topology filters into a prometheus alert rule - alert_rule["expr"] = self.tool.inject_label_matchers( - re.sub(r"%%juju_topology%%,?", "", alert_rule["expr"]), - self.topology.label_matcher_dict, - ) - - return alert_groups - - def _group_name(self, root_path: str, file_path: str, group_name: str) -> str: - """Generate group name from path and topology. - - The group name is made up of the relative path between the root dir_path, the file path, - and topology identifier. - - Args: - root_path: path to the root rules dir. - file_path: path to rule file. - group_name: original group name to keep as part of the new augmented group name - - Returns: - New group name, augmented by juju topology and relative path. - """ - rel_path = os.path.relpath(os.path.dirname(file_path), root_path) - rel_path = "" if rel_path == "." else rel_path.replace(os.path.sep, "_") - - # Generate group name: - # - name, from juju topology - # - suffix, from the relative path of the rule file; - group_name_parts = [self.topology.identifier] if self.topology else [] - group_name_parts.extend([rel_path, group_name, "alerts"]) - # filter to remove empty strings - return "_".join(filter(None, group_name_parts)) - - @classmethod - def _multi_suffix_glob( - cls, dir_path: Path, suffixes: List[str], recursive: bool = True - ) -> list: - """Helper function for getting all files in a directory that have a matching suffix. - - Args: - dir_path: path to the directory to glob from. - suffixes: list of suffixes to include in the glob (items should begin with a period). - recursive: a flag indicating whether a glob is recursive (nested) or not. - - Returns: - List of files in `dir_path` that have one of the suffixes specified in `suffixes`. - """ - all_files_in_dir = dir_path.glob("**/*" if recursive else "*") - return list(filter(lambda f: f.is_file() and f.suffix in suffixes, all_files_in_dir)) - - def _from_dir(self, dir_path: Path, recursive: bool) -> List[dict]: - """Read all rule files in a directory. - - All rules from files for the same directory are loaded into a single - group. The generated name of this group includes juju topology. - By default, only the top directory is scanned; for nested scanning, pass `recursive=True`. - - Args: - dir_path: directory containing *.rule files (alert rules without groups). - recursive: flag indicating whether to scan for rule files recursively. - - Returns: - a list of dictionaries representing prometheus alert rule groups, each dictionary - representing an alert group (structure determined by `yaml.safe_load`). - """ - alert_groups = [] # type: List[dict] - - # Gather all alerts into a list of groups - for file_path in self._multi_suffix_glob( - dir_path, [".rule", ".rules", ".yml", ".yaml"], recursive - ): - alert_groups_from_file = self._from_file(dir_path, file_path) - if alert_groups_from_file: - logger.debug("Reading alert rule from %s", file_path) - alert_groups.extend(alert_groups_from_file) - - return alert_groups - - def add_path(self, path: str, *, recursive: bool = False) -> None: - """Add rules from a dir path. - - All rules from files are aggregated into a data structure representing a single rule file. - All group names are augmented with juju topology. - - Args: - path: either a rules file or a dir of rules files. - recursive: whether to read files recursively or not (no impact if `path` is a file). - - Returns: - True if path was added else False. - """ - path = Path(path) # type: Path - if path.is_dir(): - self.alert_groups.extend(self._from_dir(path, recursive)) - elif path.is_file(): - self.alert_groups.extend(self._from_file(path.parent, path)) - else: - logger.debug("Alert rules path does not exist: %s", path) - - def as_dict(self) -> dict: - """Return standard alert rules file in dict representation. - - Returns: - a dictionary containing a single list of alert rule groups. - The list of alert rule groups is provided as value of the - "groups" dictionary key. - """ - return {"groups": self.alert_groups} if self.alert_groups else {} - - class TargetsChangedEvent(EventBase): """Event emitted when Prometheus scrape targets change.""" @@ -1056,7 +858,7 @@ class MonitoringEvents(ObjectEvents): class MetricsEndpointConsumer(Object): """A Prometheus based Monitoring service.""" - on = MonitoringEvents() + on = MonitoringEvents() # pyright: ignore def __init__(self, charm: CharmBase, relation_name: str = DEFAULT_RELATION_NAME): """A Prometheus based Monitoring service. @@ -1213,7 +1015,6 @@ def alerts(self) -> dict: try: scrape_metadata = json.loads(relation.data[relation.app]["scrape_metadata"]) identifier = JujuTopology.from_dict(scrape_metadata).identifier - alerts[identifier] = self._tool.apply_label_matchers(alert_rules) # type: ignore except KeyError as e: logger.debug( @@ -1228,6 +1029,10 @@ def alerts(self) -> dict: ) continue + # We need to append the relation info to the identifier. This is to allow for cases for there are two + # relations which eventually scrape the same application. Issue #551. + identifier = f"{identifier}_{relation.name}_{relation.id}" + alerts[identifier] = alert_rules _, errmsg = self._tool.validate_alert_rules(alert_rules) @@ -1321,7 +1126,7 @@ def _inject_alert_expr_labels(self, rules: Dict[str, Any]) -> Dict[str, Any]: # Inject topology and put it back in the list rule["expr"] = self._tool.inject_label_matchers( re.sub(r"%%juju_topology%%,?", "", rule["expr"]), - topology.label_matcher_dict, + topology.alert_expression_dict, ) except KeyError: # Some required JujuTopology key is missing. Just move on. @@ -1353,29 +1158,31 @@ def _static_scrape_config(self, relation) -> list: if not relation.units: return [] - scrape_jobs = json.loads(relation.data[relation.app].get("scrape_jobs", "[]")) + scrape_configs = json.loads(relation.data[relation.app].get("scrape_jobs", "[]")) - if not scrape_jobs: + if not scrape_configs: return [] scrape_metadata = json.loads(relation.data[relation.app].get("scrape_metadata", "{}")) if not scrape_metadata: - return scrape_jobs + return scrape_configs topology = JujuTopology.from_dict(scrape_metadata) job_name_prefix = "juju_{}_prometheus_scrape".format(topology.identifier) - scrape_jobs = PrometheusConfig.prefix_job_names(scrape_jobs, job_name_prefix) - scrape_jobs = PrometheusConfig.sanitize_scrape_configs(scrape_jobs) + scrape_configs = PrometheusConfig.prefix_job_names(scrape_configs, job_name_prefix) + scrape_configs = PrometheusConfig.sanitize_scrape_configs(scrape_configs) hosts = self._relation_hosts(relation) - scrape_jobs = PrometheusConfig.expand_wildcard_targets_into_individual_jobs( - scrape_jobs, hosts, topology + scrape_configs = PrometheusConfig.expand_wildcard_targets_into_individual_jobs( + scrape_configs, hosts, topology ) - return scrape_jobs + # For https scrape targets we still do not render a `tls_config` section because certs + # are expected to be made available by the charm via the `update-ca-certificates` mechanism. + return scrape_configs def _relation_hosts(self, relation: Relation) -> Dict[str, Tuple[str, str]]: """Returns a mapping from unit names to (address, path) tuples, for the given relation.""" @@ -1440,7 +1247,7 @@ def _dedupe_job_names(jobs: List[dict]): job["job_name"] = "{}_{}".format(job["job_name"], hashed) new_jobs = [] for key in jobs_dict: - new_jobs.extend([i for i in jobs_dict[key]]) + new_jobs.extend(list(jobs_dict[key])) # Deduplicate jobs which are equal # Again this in O(n^2) but it should be okay @@ -1491,7 +1298,7 @@ def _resolve_dir_against_charm_path(charm: CharmBase, *path_elements: str) -> st class MetricsEndpointProvider(Object): """A metrics endpoint for Prometheus.""" - on = MetricsEndpointProviderEvents() + on = MetricsEndpointProviderEvents() # pyright: ignore def __init__( self, @@ -1722,7 +1529,7 @@ def set_scrape_job_spec(self, _=None): if not self._charm.unit.is_leader(): return - alert_rules = AlertRules(topology=self.topology) + alert_rules = AlertRules(query_type="promql", topology=self.topology) alert_rules.add_path(self._alert_rules_path, recursive=True) alert_rules_as_dict = alert_rules.as_dict() @@ -1730,12 +1537,11 @@ def set_scrape_job_spec(self, _=None): relation.data[self._charm.app]["scrape_metadata"] = json.dumps(self._scrape_metadata) relation.data[self._charm.app]["scrape_jobs"] = json.dumps(self._scrape_jobs) - if alert_rules_as_dict: - # Update relation data with the string representation of the rule file. - # Juju topology is already included in the "scrape_metadata" field above. - # The consumer side of the relation uses this information to name the rules file - # that is written to the filesystem. - relation.data[self._charm.app]["alert_rules"] = json.dumps(alert_rules_as_dict) + # Update relation data with the string representation of the rule file. + # Juju topology is already included in the "scrape_metadata" field above. + # The consumer side of the relation uses this information to name the rules file + # that is written to the filesystem. + relation.data[self._charm.app]["alert_rules"] = json.dumps(alert_rules_as_dict) def _set_unit_ip(self, _=None): """Set unit host address. @@ -1793,11 +1599,10 @@ def _scrape_jobs(self) -> list: A list of dictionaries, where each dictionary specifies a single scrape job for Prometheus. """ - jobs = self._jobs if self._jobs else [DEFAULT_JOB] + jobs = self._jobs or [] if callable(self._lookaside_jobs): - return jobs + PrometheusConfig.sanitize_scrape_configs(self._lookaside_jobs()) - else: - return jobs + jobs.extend(PrometheusConfig.sanitize_scrape_configs(self._lookaside_jobs())) + return jobs or [DEFAULT_JOB] @property def _scrape_metadata(self) -> dict: @@ -1870,7 +1675,7 @@ def _update_relation_data(self, _): if not self._charm.unit.is_leader(): return - alert_rules = AlertRules() + alert_rules = AlertRules(query_type="promql") alert_rules.add_path(self.dir_path, recursive=self._recursive) alert_rules_as_dict = alert_rules.as_dict() @@ -2034,14 +1839,16 @@ def _set_prometheus_data(self, event): return jobs = [] + _type_convert_stored( - self._stored.jobs + self._stored.jobs # pyright: ignore ) # list of scrape jobs, one per relation for relation in self.model.relations[self._target_relation]: targets = self._get_targets(relation) if targets and relation.app: jobs.append(self._static_scrape_job(targets, relation.app.name)) - groups = [] + _type_convert_stored(self._stored.alert_rules) # list of alert rule groups + groups = [] + _type_convert_stored( + self._stored.alert_rules # pyright: ignore + ) # list of alert rule groups for relation in self.model.relations[self._alert_rules_relation]: unit_rules = self._get_alert_rules(relation) if unit_rules and relation.app: @@ -2078,6 +1885,7 @@ def set_target_job_data(self, targets: dict, app_name: str, **kwargs) -> None: Args: targets: a `dict` containing target information app_name: a `str` identifying the application + kwargs: a `dict` of the extra arguments passed to the function """ if not self._charm.unit.is_leader(): return @@ -2092,7 +1900,7 @@ def set_target_job_data(self, targets: dict, app_name: str, **kwargs) -> None: jobs.append(updated_job) relation.data[self._charm.app]["scrape_jobs"] = json.dumps(jobs) - if not _type_convert_stored(self._stored.jobs) == jobs: + if not _type_convert_stored(self._stored.jobs) == jobs: # pyright: ignore self._stored.jobs = jobs def _on_prometheus_targets_departed(self, event): @@ -2144,7 +1952,7 @@ def remove_prometheus_jobs(self, job_name: str, unit_name: Optional[str] = ""): relation.data[self._charm.app]["scrape_jobs"] = json.dumps(jobs) - if not _type_convert_stored(self._stored.jobs) == jobs: + if not _type_convert_stored(self._stored.jobs) == jobs: # pyright: ignore self._stored.jobs = jobs def _job_name(self, appname) -> str: @@ -2203,6 +2011,7 @@ def _static_scrape_job(self, targets, application_name, **kwargs) -> dict: "port". application_name: a string name of the application for which this static scrape job is being constructed. + kwargs: a `dict` of the extra arguments passed to the function Returns: A dictionary corresponding to a Prometheus static scrape @@ -2248,16 +2057,7 @@ def _static_config_extra_labels(self, target: Dict[str, str]) -> Dict[str, str]: logger.debug("Could not perform DNS lookup for %s", target["hostname"]) dns_name = target["hostname"] extra_info["dns_name"] = dns_name - label_re = re.compile(r'(?P