fix: add image pre-pull and debug output for kubeadm init

- Pre-pull k8s control plane images before init to speed up startup
- Add crictl pods and crictl ps -a output on failure for debugging

nixos/kubeadm/modules/k8s-common.nix

@@ -189,11 +189,17 @@ in
       sed -i "s|KUBEADM_SERVICE_SUBNET|$service_subnet|g" /tmp/kubeadm/init-config.yaml
       sed -i "s|KUBEADM_DNS_DOMAIN|$domain|g" /tmp/kubeadm/init-config.yaml
 
+      echo "==> Pre-pulling kubeadm images"
+      env -i PATH=/run/current-system/sw/bin:/usr/bin:/bin kubeadm config images pull --config /tmp/kubeadm/init-config.yaml || true
+
       env -i PATH=/run/current-system/sw/bin:/usr/bin:/bin kubeadm init \
         --config /tmp/kubeadm/init-config.yaml \
         --upload-certs \
         --ignore-preflight-errors=NumCPU,HTTPProxyCIDR,Port-10250 || {
-        echo "==> kubeadm init failed, kubelet logs:"
+        echo "==> kubeadm init failed, checking pod status:"
+        crictl pods || true
+        crictl ps -a || true
+        echo "==> kubelet logs:"
         journalctl -xeu kubelet --no-pager -n 50
         exit 1
       }