Add Wireguard-based K8s pod networking

This adds a pod networking runnable based on Wireguard which watches all nodes
and adds their K8s IPAM allocations as routes into the kernel & WireGuard. It only depends
on K8s and only performs direct routing.

Test Plan: Manually tested by spinning up a two-node cluster and running two Alpine pods pinging eachother. Can be covered by E2E tests once we can do image preseeding for the test infra (T793).

Bug: T487

X-Origin-Diff: phab/D573
GitOrigin-RevId: ba3fc36f421fd75002f6cf8bea25ed6f1eb457b0
diff --git a/core/internal/containerd/config.toml b/core/internal/containerd/config.toml
index 5a7e2f6..415391a 100644
--- a/core/internal/containerd/config.toml
+++ b/core/internal/containerd/config.toml
@@ -90,8 +90,8 @@
     [plugins."io.containerd.grpc.v1.cri".cni]
       bin_dir = "/containerd/bin/cni"
       conf_dir = "/containerd/conf/cni"
-      max_conf_num = 1
-      conf_template = ""
+      max_conf_num = 0
+      conf_template = "/containerd/conf/cnispec.gojson"
     [plugins."io.containerd.grpc.v1.cri".registry]
       [plugins."io.containerd.grpc.v1.cri".registry.mirrors]
         [plugins."io.containerd.grpc.v1.cri".registry.mirrors."docker.io"]