1 files changed, 59 insertions, 9 deletions

diff --git a/nixos/modules/services/cluster/kubernetes/flannel.nix b/nixos/modules/services/cluster/kubernetes/flannel.nix
index 93ee2fd65eeb..e79fbcb62002 100644
--- a/nixos/modules/services/cluster/kubernetes/flannel.nix
+++ b/nixos/modules/services/cluster/kubernetes/flannel.nix
@@ -24,16 +24,26 @@ in
   ###### interface
   options.services.kubernetes.flannel = {
     enable = mkEnableOption "enable flannel networking";
+    kubeconfig = top.lib.mkKubeConfigOptions "Kubernetes flannel";
   };
 
   ###### implementation
-  config = mkIf cfg.enable {
+  config = let
+
+    flannelPaths = filter (a: a != null) [
+      cfg.kubeconfig.caFile
+      cfg.kubeconfig.certFile
+      cfg.kubeconfig.keyFile
+    ];
+    kubeconfig = top.lib.mkKubeConfig "flannel" cfg.kubeconfig;
+
+  in mkIf cfg.enable {
     services.flannel = {
 
       enable = mkDefault true;
       network = mkDefault top.clusterCidr;
-      inherit storageBackend;
-      nodeName = config.services.kubernetes.kubelet.hostname;
+      inherit storageBackend kubeconfig;
+      nodeName = top.kubelet.hostname;
     };
 
     services.kubernetes.kubelet = {
@@ -48,24 +58,66 @@ in
       }];
     };
 
-    systemd.services."mk-docker-opts" = {
+    systemd.services.mk-docker-opts = {
       description = "Pre-Docker Actions";
+      wantedBy = [ "flannel.target" ];
+      before = [ "flannel.target" ];
       path = with pkgs; [ gawk gnugrep ];
       script = ''
         ${mkDockerOpts}/mk-docker-opts -d /run/flannel/docker
         systemctl restart docker
       '';
+      unitConfig.ConditionPathExists = [ "/run/flannel/subnet.env" ];
       serviceConfig.Type = "oneshot";
     };
 
-    systemd.paths."flannel-subnet-env" = {
-      wantedBy = [ "flannel.service" ];
+    systemd.paths.flannel-subnet-env = {
+      wantedBy = [ "mk-docker-opts.service" ];
       pathConfig = {
-        PathModified = "/run/flannel/subnet.env";
+        PathExists = [ "/run/flannel/subnet.env" ];
+        PathChanged = [ "/run/flannel/subnet.env" ];
         Unit = "mk-docker-opts.service";
       };
     };
 
+    systemd.targets.flannel = {
+      wantedBy = [ "kube-node-online.target" ];
+      before = [ "kube-node-online.target" ];
+    };
+
+    systemd.services.flannel = {
+      wantedBy = [ "flannel.target" ];
+      after = [ "kubelet.target" ];
+      before = [ "flannel.target" ];
+      path = with pkgs; [ iptables kubectl ];
+      environment.KUBECONFIG = kubeconfig;
+      preStart = let
+        args = [
+          "--selector=kubernetes.io/hostname=${top.kubelet.hostname}"
+          # flannel exits if node is not registered yet, before that there is no podCIDR
+          "--output=jsonpath={.items[0].spec.podCIDR}"
+          # if jsonpath cannot be resolved exit with status 1
+          "--allow-missing-template-keys=false"
+        ];
+      in ''
+        until kubectl get nodes ${concatStringsSep " " args} 2>/dev/null; do
+          echo Waiting for ${top.kubelet.hostname} to be RegisteredNode
+          sleep 1
+        done
+      '';
+      unitConfig.ConditionPathExists = flannelPaths;
+    };
+
+    systemd.paths.flannel = {
+      wantedBy = [ "flannel.service" ];
+      pathConfig = {
+        PathExists = flannelPaths;
+        PathChanged = flannelPaths;
+      };
+    };
+
+    services.kubernetes.flannel.kubeconfig.server = mkDefault top.apiserverAddress;
+
     systemd.services.docker = {
       environment.DOCKER_OPTS = "-b none";
       serviceConfig.EnvironmentFile = "-/run/flannel/docker";
@@ -92,7 +144,6 @@ in
 
     # give flannel som kubernetes rbac permissions if applicable
     services.kubernetes.addonManager.bootstrapAddons = mkIf ((storageBackend == "kubernetes") && (elem "RBAC" top.apiserver.authorizationMode)) {
-
       flannel-cr = {
         apiVersion = "rbac.authorization.k8s.io/v1beta1";
         kind = "ClusterRole";
@@ -128,7 +179,6 @@ in
           name = "flannel-client";
         }];
       };
-
     };
   };
 }