Tweak the containerd garbage collect threshold on kubelets.

Pods were getting evicted due to disk pressure, so this causes garbage collection to trigger sooner.

nix/kubernetes/flake.lock

@@ -22,11 +22,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1780290312,
-        "narHash": "sha256-eTAlX0CwgB84Ts3GaBd944A3DRXVMzgA0EqroZBISUo=",
+        "lastModified": 1781152676,
+        "narHash": "sha256-RxWs5ND31KzTG7wvMM+PMfUjyNpmIEr999lqNARaM5o=",
         "owner": "nix-community",
         "repo": "disko",
-        "rev": "115e5211780054d8a890b41f0b7734cafad54dfe",
+        "rev": "ff8702b4de27f72b4c78573dfb89ec74e36abdf1",
         "type": "github"
       },
       "original": {
@@ -164,11 +164,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1780749050,
-        "narHash": "sha256-3av0pIjlOWQ6rDbNOmpUSvbNnJkGORQKKjb4LtCZsIY=",
+        "lastModified": 1784120854,
+        "narHash": "sha256-KesHgItiZPgGX740axSiQLcIQ8D24MDqNpkKYWIek8k=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "a799d3e3886da994fa307f817a6bc705ae538eeb",
+        "rev": "753cc8a3a87467296ddd1fa93f0cc3e81120ee46",
         "type": "github"
       },
       "original": {

nix/kubernetes/roles/kubelet/default.nix

@@ -48,6 +48,12 @@ let
       "fd00:3e42:e349::10"
     ];
     imageMaximumGCAge = "24h"; # Delete unused images after 1 day.
+    imageGCHighThresholdPercent = 80;
+    imageGCLowThresholdPercent = 70;
+    evictionHard = {
+      "nodefs.available" = "5%";
+      "imagefs.available" = "10%";
+    };
   };
   kubelet_config_file = (to_yaml_file "kubelet-config.yaml" kubelet_config);
 in