Major improvement in OSM charms
[osm/devops.git] / installers / charm / prometheus / src / charm.py
index 4371d47..3d72cac 100755 (executable)
 # osm-charmers@lists.launchpad.net
 ##
 
+# pylint: disable=E0213
+
 import logging
-from typing import Dict, List, NoReturn
+from typing import Optional, NoReturn
+from ipaddress import ip_network
 
-from ops.charm import CharmBase
-from ops.framework import EventBase, StoredState
+from ops.framework import EventBase
 from ops.main import main
-from ops.model import ActiveStatus, Application, BlockedStatus, MaintenanceStatus, Unit
-from oci_image import OCIImageResource, OCIImageResourceError
 
-from pod_spec import make_pod_spec
+from opslib.osm.charm import CharmedOsmBase
+
+from opslib.osm.pod import (
+    IngressResourceV3Builder,
+    FilesV3Builder,
+    ContainerV3Builder,
+    PodSpecV3Builder,
+)
+
+
+from opslib.osm.validator import (
+    ModelValidator,
+    validator,
+)
+
+from opslib.osm.interfaces.prometheus import PrometheusServer
+from urllib.parse import urlparse
 
 logger = logging.getLogger(__name__)
 
-PROMETHEUS_PORT = 9090
+PORT = 9090
 
 
-class RelationsMissing(Exception):
-    def __init__(self, missing_relations: List):
-        self.message = ""
-        if missing_relations and isinstance(missing_relations, list):
-            self.message += f'Waiting for {", ".join(missing_relations)} relation'
-            if "," in self.message:
-                self.message += "s"
+class ConfigModel(ModelValidator):
+    web_subpath: str
+    default_target: str
+    max_file_size: int
+    site_url: Optional[str]
+    ingress_whitelist_source_range: Optional[str]
+    tls_secret_name: Optional[str]
+    enable_web_admin_api: bool
 
+    @validator("web_subpath")
+    def validate_web_subpath(cls, v):
+        if len(v) < 1:
+            raise ValueError("web-subpath must be a non-empty string")
+        return v
 
-class RelationDefinition:
-    def __init__(self, relation_name: str, keys: List, source_type):
-        if source_type != Application and source_type != Unit:
-            raise TypeError(
-                "source_type should be ops.model.Application or ops.model.Unit"
-            )
-        self.relation_name = relation_name
-        self.keys = keys
-        self.source_type = source_type
-
-
-def check_missing_relation_data(
-    data: Dict,
-    expected_relations_data: List[RelationDefinition],
-):
-    missing_relations = []
-    for relation_data in expected_relations_data:
-        if not all(
-            f"{relation_data.relation_name}_{k}" in data for k in relation_data.keys
-        ):
-            missing_relations.append(relation_data.relation_name)
-    if missing_relations:
-        raise RelationsMissing(missing_relations)
-
-
-def get_relation_data(
-    charm: CharmBase,
-    relation_data: RelationDefinition,
-) -> Dict:
-    data = {}
-    relation = charm.model.get_relation(relation_data.relation_name)
-    if relation:
-        self_app_unit = (
-            charm.app if relation_data.source_type == Application else charm.unit
-        )
-        expected_type = relation_data.source_type
-        for app_unit in relation.data:
-            if app_unit != self_app_unit and isinstance(app_unit, expected_type):
-                if all(k in relation.data[app_unit] for k in relation_data.keys):
-                    for k in relation_data.keys:
-                        data[f"{relation_data.relation_name}_{k}"] = relation.data[
-                            app_unit
-                        ].get(k)
-                    break
-    return data
-
-
-class PrometheusCharm(CharmBase):
-    """Prometheus Charm."""
+    @validator("max_file_size")
+    def validate_max_file_size(cls, v):
+        if v < 0:
+            raise ValueError("value must be equal or greater than 0")
+        return v
 
-    state = StoredState()
+    @validator("site_url")
+    def validate_site_url(cls, v):
+        if v:
+            parsed = urlparse(v)
+            if not parsed.scheme.startswith("http"):
+                raise ValueError("value must start with http")
+        return v
 
-    def __init__(self, *args) -> NoReturn:
-        """Prometheus Charm constructor."""
-        super().__init__(*args)
+    @validator("ingress_whitelist_source_range")
+    def validate_ingress_whitelist_source_range(cls, v):
+        if v:
+            ip_network(v)
+        return v
 
-        # Internal state initialization
-        self.state.set_default(pod_spec=None)
 
-        self.port = PROMETHEUS_PORT
-        self.image = OCIImageResource(self, "image")
+class PrometheusCharm(CharmedOsmBase):
 
-        # Registering regular events
-        self.framework.observe(self.on.start, self.configure_pod)
-        self.framework.observe(self.on.config_changed, self.configure_pod)
+    """Prometheus Charm."""
+
+    def __init__(self, *args) -> NoReturn:
+        """Prometheus Charm constructor."""
+        super().__init__(*args, oci_image="image")
 
         # Registering provided relation events
+        self.prometheus = PrometheusServer(self, "prometheus")
         self.framework.observe(
-            self.on.prometheus_relation_joined, self._publish_prometheus_info
+            self.on.prometheus_relation_joined,  # pylint: disable=E1101
+            self._publish_prometheus_info,
         )
 
     def _publish_prometheus_info(self, event: EventBase) -> NoReturn:
-        """Publishes Prometheus information.
-
-        Args:
-            event (EventBase): Prometheus relation event.
-        """
-        if self.unit.is_leader():
-            rel_data = {
-                "host": self.model.app.name,
-                "port": str(PROMETHEUS_PORT),
+        self.prometheus.publish_info(self.app.name, PORT)
+
+    def _build_files(self, config: ConfigModel):
+        files_builder = FilesV3Builder()
+        files_builder.add_file(
+            "prometheus.yml",
+            (
+                "global:\n"
+                "  scrape_interval: 15s\n"
+                "  evaluation_interval: 15s\n"
+                "alerting:\n"
+                "  alertmanagers:\n"
+                "    - static_configs:\n"
+                "        - targets:\n"
+                "rule_files:\n"
+                "scrape_configs:\n"
+                "  - job_name: 'prometheus'\n"
+                "    static_configs:\n"
+                f"      - targets: [{config.default_target}]\n"
+            ),
+        )
+        return files_builder.build()
+
+    def build_pod_spec(self, image_info):
+        # Validate config
+        config = ConfigModel(**dict(self.config))
+        # Create Builder for the PodSpec
+        pod_spec_builder = PodSpecV3Builder()
+        # Build Container
+        container_builder = ContainerV3Builder(self.app.name, image_info)
+        container_builder.add_port(name=self.app.name, port=PORT)
+        container_builder.add_http_readiness_probe(
+            "/-/ready",
+            PORT,
+            initial_delay_seconds=10,
+            timeout_seconds=30,
+        )
+        container_builder.add_http_liveness_probe(
+            "/-/healthy",
+            PORT,
+            initial_delay_seconds=30,
+            period_seconds=30,
+        )
+        command = [
+            "/bin/prometheus",
+            "--config.file=/etc/prometheus/prometheus.yml",
+            "--storage.tsdb.path=/prometheus",
+            "--web.console.libraries=/usr/share/prometheus/console_libraries",
+            "--web.console.templates=/usr/share/prometheus/consoles",
+            f"--web.route-prefix={config.web_subpath}",
+            f"--web.external-url=http://localhost:{PORT}{config.web_subpath}",
+        ]
+        if config.enable_web_admin_api:
+            command.append("--web.enable-admin-api")
+        container_builder.add_command(command)
+        container_builder.add_volume_config(
+            "config", "/etc/prometheus", self._build_files(config)
+        )
+        container = container_builder.build()
+        # Add container to pod spec
+        pod_spec_builder.add_container(container)
+        # Add ingress resources to pod spec if site url exists
+        if config.site_url:
+            parsed = urlparse(config.site_url)
+            annotations = {
+                "nginx.ingress.kubernetes.io/proxy-body-size": "{}".format(
+                    str(config.max_file_size) + "m"
+                    if config.max_file_size > 0
+                    else config.max_file_size
+                ),
             }
-            for k, v in rel_data.items():
-                event.relation.data[self.app][k] = v
-
-    @property
-    def relations_requirements(self):
-        return []
-
-    def get_relation_state(self):
-        relation_state = {}
-        for relation_requirements in self.relations_requirements:
-            data = get_relation_data(self, relation_requirements)
-            relation_state = {**relation_state, **data}
-        check_missing_relation_data(relation_state, self.relations_requirements)
-        return relation_state
-
-    def configure_pod(self, _=None) -> NoReturn:
-        """Assemble the pod spec and apply it, if possible.
-
-        Args:
-            event (EventBase): Hook or Relation event that started the
-                               function.
-        """
-        if not self.unit.is_leader():
-            self.unit.status = ActiveStatus("ready")
-            return
-
-        relation_state = None
-        try:
-            relation_state = self.get_relation_state()
-        except RelationsMissing as exc:
-            logger.exception("Relation missing error")
-            self.unit.status = BlockedStatus(exc.message)
-            return
-
-        self.unit.status = MaintenanceStatus("Assembling pod spec")
-
-        # Fetch image information
-        try:
-            self.unit.status = MaintenanceStatus("Fetching image information")
-            image_info = self.image.fetch()
-        except OCIImageResourceError:
-            self.unit.status = BlockedStatus("Error fetching image information")
-            return
-
-        try:
-            pod_spec = make_pod_spec(
-                image_info,
-                self.model.config,
-                relation_state,
-                self.model.app.name,
-                self.port,
+            ingress_resource_builder = IngressResourceV3Builder(
+                f"{self.app.name}-ingress", annotations
             )
-        except ValueError as exc:
-            logger.exception("Config/Relation data validation error")
-            self.unit.status = BlockedStatus(str(exc))
-            return
-
-        if self.state.pod_spec != pod_spec:
-            self.model.pod.set_spec(pod_spec)
-            self.state.pod_spec = pod_spec
 
-        self.unit.status = ActiveStatus("ready")
+            if config.ingress_whitelist_source_range:
+                annotations[
+                    "nginx.ingress.kubernetes.io/whitelist-source-range"
+                ] = config.ingress_whitelist_source_range
+
+            if parsed.scheme == "https":
+                ingress_resource_builder.add_tls(
+                    [parsed.hostname], config.tls_secret_name
+                )
+            else:
+                annotations["nginx.ingress.kubernetes.io/ssl-redirect"] = "false"
+
+            ingress_resource_builder.add_rule(parsed.hostname, self.app.name, PORT)
+            ingress_resource = ingress_resource_builder.build()
+            pod_spec_builder.add_ingress_resource(ingress_resource)
+        return pod_spec_builder.build()
 
 
 if __name__ == "__main__":