Implementations of Prometheus Client

app/classes/models/server_stats.py

@@ -3,11 +3,14 @@ import logging
 import datetime
 from datetime import timedelta
 
+from prometheus_client import Gauge
+
 from app.classes.models.servers import Servers, HelperServers
 from app.classes.shared.helpers import Helpers
 from app.classes.shared.main_models import DatabaseShortcuts
 from app.classes.shared.migration import MigrationManager
 
+
 try:
     from peewee import (
         SqliteDatabase,
@@ -29,6 +32,13 @@ logger = logging.getLogger(__name__)
 peewee_logger = logging.getLogger("peewee")
 peewee_logger.setLevel(logging.INFO)
 
+# REGISTRY Entries for Server Stats functions
+ONLINE_PLAYERS = Gauge(
+    name="online_players",
+    documentation="The number of players online for a server",
+    labelnames=["server_id"],
+)
+
 
 # **********************************************************************************
 #                                   Servers Stats Class
@@ -157,6 +167,8 @@ class HelperServerStats:
         self.database.connect(reuse_if_open=True)
         server_id = server_stats.get("id", 0)
 
+        ONLINE_PLAYERS.labels(f"{self.server_id}").set(server_stats.get("online"))
+
         if server_id == 0:
             logger.warning("Stats saving failed with error: Server unknown (id = 0)")
             return

app/classes/web/metrics_handler.py

@@ -0,0 +1,50 @@
+import logging
+import typing as t
+
+from prometheus_client import REGISTRY, CollectorRegistry
+from prometheus_client.exposition import _bake_output
+from prometheus_client.exposition import parse_qs, urlparse
+
+from app.classes.web.base_api_handler import BaseApiHandler
+
+logger = logging.getLogger(__name__)
+
+
+class BaseMetricsHandler(BaseApiHandler):
+    """HTTP handler that gives metrics from ``REGISTRY``."""
+
+    registry: CollectorRegistry = REGISTRY
+
+    def get_registry(self) -> None:
+        # Prepare parameters
+        registry = self.registry
+        accept_header = self.request.headers.get("Accept")
+        accept_encoding_header = self.request.headers.get("Accept-Encoding")
+        params = parse_qs(urlparse(self.request.path).query)
+        # Bake output
+        status, headers, output = _bake_output(
+            registry, accept_header, accept_encoding_header, params, False
+        )
+        # Return output
+        self.finish_metrics(int(status.split(" ", maxsplit=1)[0]), headers, output)
+
+    @classmethod
+    def factory(cls, registry: CollectorRegistry) -> type:
+        """Returns a dynamic MetricsHandler class tied
+        to the passed registry.
+        """
+        # This implementation relies on MetricsHandler.registry
+        #  (defined above and defaulted to REGISTRY).
+
+        # As we have unicode_literals, we need to create a str()
+        #  object for type().
+        cls_name = str(cls.__name__)
+        MyMetricsHandler = type(cls_name, (cls, object), {"registry": registry})
+        return MyMetricsHandler
+
+    def finish_metrics(self, status: int, headers, data: t.Dict[str, t.Any]):
+        self.set_status(status)
+        self.set_header("Content-Type", "text/plain")
+        for header in headers:
+            self.set_header(*header)
+        self.finish(data)

app/classes/web/routes/metrics/index.py

@@ -0,0 +1,19 @@
+from prometheus_client import Info
+from app.classes.web.metrics_handler import BaseMetricsHandler
+
+CRAFTY_INFO = Info("Crafty_Controller", "Infos of this Crafty Instance")
+
+
+# Decorate function with metric.
+class ApiOpenMetricsIndexHandler(BaseMetricsHandler):
+    def get(self):
+        auth_data = self.authenticate_user()
+        if not auth_data:
+            return
+
+        version = f"{self.helper.get_version().get('major')}.{self.helper.get_version().get('minor')}.{self.helper.get_version().get('sub')}"
+        CRAFTY_INFO.info(
+            {"version": version, "docker": f"{self.helper.is_env_docker()}"}
+        )
+
+        self.get_registry()

app/classes/web/routes/metrics/metrics_handlers.py

@@ -0,0 +1,18 @@
+from app.classes.web.routes.metrics.index import ApiOpenMetricsIndexHandler
+from app.classes.web.routes.metrics.servers import ApiOpenMetricsServersHandler
+
+
+def metrics_handlers(handler_args):
+    return [
+        # OpenMetrics routes
+        (
+            r"/metrics?",
+            ApiOpenMetricsIndexHandler,
+            handler_args,
+        ),
+        (
+            r"/metrics/servers/(0-9)+?",
+            ApiOpenMetricsServersHandler,
+            handler_args,
+        ),
+    ]

app/classes/web/routes/metrics/servers.py

@@ -0,0 +1,12 @@
+from prometheus_client import Histogram
+from app.classes.web.metrics_handler import BaseMetricsHandler
+
+
+# Decorate function with metric.
+class ApiOpenMetricsServersHandler(BaseMetricsHandler):
+    def get(self):
+        auth_data = self.authenticate_user()
+        if not auth_data:
+            return
+
+        self.get_registry()

app/classes/web/tornado_handler.py

@@ -20,6 +20,7 @@ from app.classes.web.public_handler import PublicHandler
 from app.classes.web.panel_handler import PanelHandler
 from app.classes.web.default_handler import DefaultHandler
 from app.classes.web.routes.api.api_handlers import api_handlers
+from app.classes.web.routes.metrics.metrics_handlers import metrics_handlers
 from app.classes.web.server_handler import ServerHandler
 from app.classes.web.ajax_handler import AjaxHandler
 from app.classes.web.api_handler import (
@@ -169,6 +170,8 @@ class Webserver:
             (r"/api/v1/users/delete_user", DeleteUser, handler_args),
             # API Routes V2
             *api_handlers(handler_args),
+            # API Routes OpenMetrics
+            *metrics_handlers(handler_args),
             # Using this one at the end
             # to catch all the other requests to Public Handler
             (r"/(.*)", PublicHandler, handler_args),

requirements.txt

@@ -9,7 +9,7 @@ cryptography==41.0.1
 libgravatar==1.0.0
 peewee==3.13
 pexpect==4.8
-psutil==5.9
+psutil==5.9.5
 pyOpenSSL==23.2.0
 pyjwt==2.4.0
 PyYAML==6.0.1
@@ -19,3 +19,4 @@ tornado==6.3.2
 tzlocal==4.0
 jsonschema==4.5.1
 orjson==3.8.12
+prometheus-client==0.17.1