Implement prometheus integration

2 files changed, 58 insertions, 1 deletions

diff --git a/robusta_krr/utils/configurable.py b/robusta_krr/utils/configurable.py
index e4c80f6..d2f1442 100644
--- a/robusta_krr/utils/configurable.py
+++ b/robusta_krr/utils/configurable.py
@@ -1,3 +1,4 @@
+import abc
 from typing import Literal
 
 from rich.console import Console
@@ -7,7 +8,7 @@ from robusta_krr.core.models.config import Config
 console = Console()
 
 
-class Configurable:
+class Configurable(abc.ABC):
     """
     A class that can be configured with a Config object.
     Opens the possibility to use echo and debug methods
diff --git a/robusta_krr/utils/service_discovery.py b/robusta_krr/utils/service_discovery.py
new file mode 100644
index 0000000..8c498fe
--- /dev/null
+++ b/robusta_krr/utils/service_discovery.py
@@ -0,0 +1,56 @@
+import logging
+
+from cachetools import TTLCache
+from kubernetes import client
+from kubernetes.client import V1ServiceList
+from kubernetes.client.api_client import ApiClient
+from kubernetes.client.models.v1_service import V1Service
+
+from robusta_krr.utils.configurable import Configurable
+
+
+class ServiceDiscovery(Configurable):
+    SERVICE_CACHE_TTL_SEC = 900
+    cache: TTLCache = TTLCache(maxsize=1, ttl=SERVICE_CACHE_TTL_SEC)
+
+    def find_service_url(self, label_selector: str, *, api_client: ApiClient | None = None) -> str | None:
+        """
+        Get the url of an in-cluster service with a specific label
+        """
+        # we do it this way because there is a weird issue with hikaru's ServiceList.listServiceForAllNamespaces()
+        v1 = client.CoreV1Api(api_client=api_client)
+        svc_list: V1ServiceList = v1.list_service_for_all_namespaces(label_selector=label_selector)
+        if not svc_list.items:
+            return None
+
+        svc: V1Service = svc_list.items[0]
+        name = svc.metadata.name
+        namespace = svc.metadata.namespace
+        port = svc.spec.ports[0].port
+
+        if self.config.inside_cluster:
+            return f"http://{name}.{namespace}.svc.cluster.local:{port}"
+
+        elif api_client is not None:
+            return f"{api_client.configuration.host}/api/v1/namespaces/{namespace}/services/{name}:{port}/proxy"
+
+        return None
+
+    def find_url(self, selectors: list[str], *, api_client: ApiClient | None = None) -> str | None:
+        """
+        Try to autodiscover the url of an in-cluster service
+        """
+        cache_key = ",".join(selectors)
+        cached_value = self.cache.get(cache_key)
+        if cached_value:
+            return cached_value
+
+        for label_selector in selectors:
+            logging.debug(f"Trying to find service with label selector {label_selector}")
+            service_url = self.find_service_url(label_selector, api_client=api_client)
+            if service_url:
+                logging.debug(f"Found service with label selector {label_selector}")
+                self.cache[cache_key] = service_url
+                return service_url
+
+        return None