metropolis/core/metrics: expose containerd metrics endpoint

This adds containerd as another metrics endpoint. It is only available
on nodes with the KubernetesWorker role.

Change-Id: I5f6269165a81d9a4c4cff48d3ed6b6a55d7f4f46
Reviewed-on: https://review.monogon.dev/c/monogon/+/2861
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/metropolis/node/kubernetes/containerd/config.toml b/metropolis/node/kubernetes/containerd/config.toml
index 4f6e31c..177e0d0 100644
--- a/metropolis/node/kubernetes/containerd/config.toml
+++ b/metropolis/node/kubernetes/containerd/config.toml
@@ -28,7 +28,7 @@
   level = ""
 
 [metrics]
-  address = ""
+  address = "127.0.0.1:7846"
   grpc_histogram = false
 
 [cgroup]