Merge pull request #56789 from mayflower/upstream-k8s-refactor

nixos/kubernetes: stabilize cluster deployment/startup across machines

nixos/modules/services/cluster/kubernetes/default.nix

@@ -263,6 +263,30 @@ in {
         wantedBy = [ "multi-user.target" ];
       };
 
+      systemd.targets.kube-control-plane-online = {
+        wantedBy = [ "kubernetes.target" ];
+        before = [ "kubernetes.target" ];
+      };
+
+      systemd.services.kube-control-plane-online = rec {
+        description = "Kubernetes control plane is online";
+        wantedBy = [ "kube-control-plane-online.target" ];
+        after = [ "kube-scheduler.service" "kube-controller-manager.service" ];
+        before = [ "kube-control-plane-online.target" ];
+        environment.KUBECONFIG = cfg.lib.mkKubeConfig "default" cfg.kubeconfig;
+        path = [ pkgs.kubectl ];
+        preStart = ''
+          until kubectl get --raw=/healthz 2>/dev/null; do
+            echo kubectl get --raw=/healthz: exit status $?
+            sleep 3
+          done
+        '';
+        script = "echo Ok";
+        serviceConfig = {
+          TimeoutSec = "500";
+        };
+      };
+
       systemd.tmpfiles.rules = [
         "d /opt/cni/bin 0755 root root -"
         "d /run/kubernetes 0755 kubernetes kubernetes -"
@@ -286,6 +310,8 @@ in {
       services.kubernetes.apiserverAddress = mkDefault ("https://${if cfg.apiserver.advertiseAddress != null
                           then cfg.apiserver.advertiseAddress
                           else "${cfg.masterAddress}:${toString cfg.apiserver.securePort}"}");
+
+      services.kubernetes.kubeconfig.server = mkDefault cfg.apiserverAddress;
     })
   ];
 }