feat: counter running containers total metric

container_exporter.py

@@ -42,6 +42,8 @@ async def lifespan(app: FastAPI):
 counter_net_rx = Gauge("cxp_network_rx_bytes_total", "Total bytes received over network", ['container_name'])
 counter_net_tx = Gauge("cxp_network_tx_bytes_total", "Total bytes sent over network", ['container_name'])
 
+counter_running_containers_total = Gauge("cxp_running_cotainers_total", "Total number of running containers")
+
 async def get_containers(all=False) -> list[DockerContainer]:
     return await docker_client.containers.list(all=all)
 
@@ -56,9 +58,12 @@ def update_container_status(running_containers:list[DockerContainer]):
             gauge_container_status.labels(container_name=name).set(2)
 
 # Async metrics gathering
-async def container_stats( running_containers: list[DockerContainer]):
+async def container_stats(running_containers: list[DockerContainer]):
     all_stats = await stat.get_containers_stats(running_containers)
+    running_containers_total = len(running_containers)
 
+    counter_running_containers_total.set(running_containers_total)
+
     for stats in all_stats:
         name = stats[0].get('name', stats[0].get('id', 'Unkown').lstrip("/")).lstrip("/")
 
@@ -80,7 +85,9 @@ async def container_stats( running_containers: list[DockerContainer]):
 ]
 
 # Metrics we want to always keep, and set to 0 instead
-persistent_metrics: list[Gauge] = [gauge_container_status]
+persistent_metrics: list[Gauge] = [
+    gauge_container_status, counter_running_containers_total
+]
 
 
 @app.get("/")
@@ -115,4 +122,4 @@ async def metrics():
         )
     except Exception as e:
         logger.error("Error running metrics collection: %s", e, exc_info=settings.CONTAINER_EXPORTER_DEBUG)
-        return PlainTextResponse(f"Error running metrics collection: {str(e)}", status_code=500)
+        return PlainTextResponse(f"Error running metrics collection: {str(e)}", status_code=500)

utils/metrics.py

@@ -14,6 +14,8 @@ def prune_stale_metrics(active_names: Iterable[str], prunable_metrics: list[Prom
     active_set = set(active_names)
 
     for metric in prunable_metrics:
+        if not hasattr(metric, '_metrics'):
+            continue
         for labels in metric._metrics:
             name = labels[0]
             if name not in active_set:
@@ -25,6 +27,8 @@ def prune_stale_metrics(active_names: Iterable[str], prunable_metrics: list[Prom
                     metric.clear()                    
 
     for metric in persistent_metrics:
+        if not hasattr(metric, '_metrics'):
+            continue
         for labels in list(metric._metrics):
             name = labels[0]
             if name not in active_set:
@@ -37,4 +41,4 @@ def normalize_name(raw_names: list[str], fallback_id: str) -> str:
     """
     if raw_names and isinstance(raw_names, list) and raw_names[0]:
         return raw_names[0].lstrip("/")
-    return fallback_id[:12]
+    return fallback_id[:12]