From ee9dd4386a061594ad69ff5a3a683f899f9f8c93 Mon Sep 17 00:00:00 2001
From: Christian Albrecht <christian.albrecht@mayflower.de>
Date: Mon, 11 Mar 2019 10:44:24 +0100
Subject: Cleanup pki: addon-manager

---
 .../services/cluster/kubernetes/addon-manager.nix  | 77 ++++++++++++++++++----
 1 file changed, 63 insertions(+), 14 deletions(-)

(limited to 'nixos/modules/services/cluster/kubernetes/addon-manager.nix')

diff --git a/nixos/modules/services/cluster/kubernetes/addon-manager.nix b/nixos/modules/services/cluster/kubernetes/addon-manager.nix
index 406b20b0d8d..b9a56811d2b 100644
--- a/nixos/modules/services/cluster/kubernetes/addon-manager.nix
+++ b/nixos/modules/services/cluster/kubernetes/addon-manager.nix
@@ -63,24 +63,48 @@ in
     };
 
     enable = mkEnableOption "Whether to enable Kubernetes addon manager.";
+
+    kubeconfig = top.lib.mkKubeConfigOptions "Kubernetes addon manager";
+    bootstrapAddonsKubeconfig = top.lib.mkKubeConfigOptions "Kubernetes addon manager bootstrap";
   };
 
   ###### implementation
-  config = mkIf cfg.enable {
+  config = let
+
+    addonManagerPaths = filter (a: a != null) [
+      cfg.kubeconfig.caFile
+      cfg.kubeconfig.certFile
+      cfg.kubeconfig.keyFile
+    ];
+    bootstrapAddonsPaths = filter (a: a != null) [
+      cfg.bootstrapAddonsKubeconfig.caFile
+      cfg.bootstrapAddonsKubeconfig.certFile
+      cfg.bootstrapAddonsKubeconfig.keyFile
+    ];
+
+  in mkIf cfg.enable {
     environment.etc."kubernetes/addons".source = "${addons}/";
 
+    #TODO: Get rid of kube-addon-manager in the future for the following reasons
+    # - it is basically just a shell script wrapped around kubectl
+    # - it assumes that it is clusterAdmin or can gain clusterAdmin rights through serviceAccount
+    # - it is designed to be used with k8s system components only
+    # - it would be better with a more Nix-oriented way of managing addons
     systemd.services.kube-addon-manager = {
       description = "Kubernetes addon manager";
-      wantedBy = [ "kube-control-plane-online.target" ];
-      after = [ "kube-addon-manager-bootstrap.service" ];
-      before = [ "kube-control-plane-online.target" ];
-      environment.ADDON_PATH = "/etc/kubernetes/addons/";
-      path = [ pkgs.gawk ];
+      wantedBy = [ "kubernetes.target" ];
+      after = [ "kube-node-online.target" ];
+      before = [ "kubernetes.target" ];
+      environment = {
+        ADDON_PATH = "/etc/kubernetes/addons/";
+        KUBECONFIG = top.lib.mkKubeConfig "kube-addon-manager" cfg.kubeconfig;
+      };
+      path = with pkgs; [ gawk kubectl ];
       preStart = ''
-        ${top.lib.mkWaitCurl ( with config.systemd.services.kube-addon-manager; {
-          path = "/api/v1/namespaces/kube-system/serviceaccounts/default";
-          cacert = top.caFile;
-        } // optionalAttrs (environment ? cert) { inherit (environment) cert key; })}
+        until kubectl -n kube-system get serviceaccounts/default 2>/dev/null; do
+          echo kubectl -n kube-system get serviceaccounts/default: exit status $?
+          sleep 2
+        done
       '';
       serviceConfig = {
         Slice = "kubernetes.slice";
@@ -91,27 +115,52 @@ in
         Restart = "on-failure";
         RestartSec = 10;
       };
+      unitConfig.ConditionPathExists = addonManagerPaths;
+    };
+
+    systemd.paths.kube-addon-manager = {
+      wantedBy = [ "kube-addon-manager.service" ];
+      pathConfig = {
+        PathExists = addonManagerPaths;
+        PathChanged = addonManagerPaths;
+      };
     };
 
+    services.kubernetes.addonManager.kubeconfig.server = mkDefault top.apiserverAddress;
+
     systemd.services.kube-addon-manager-bootstrap = mkIf (top.apiserver.enable && top.addonManager.bootstrapAddons != {}) {
       wantedBy = [ "kube-control-plane-online.target" ];
       after = [ "kube-apiserver.service" ];
       before = [ "kube-control-plane-online.target" ];
       path = [ pkgs.kubectl ];
+      environment = {
+        KUBECONFIG = top.lib.mkKubeConfig "kube-addon-manager-bootstrap" cfg.bootstrapAddonsKubeconfig;
+      };
       preStart = with pkgs; let
         files = mapAttrsToList (n: v: writeText "${n}.json" (builtins.toJSON v))
           cfg.bootstrapAddons;
       in ''
-        ${top.lib.mkWaitCurl ( with config.systemd.services.kube-addon-manager-bootstrap; {
-          path = "/api";
-          cacert = top.caFile;
-        } // optionalAttrs (environment ? cert) { inherit (environment) cert key; })}
+        until kubectl auth can-i '*' '*' -q 2>/dev/null; do
+          echo kubectl auth can-i '*' '*': exit status $?
+          sleep 2
+        done
 
         kubectl apply -f ${concatStringsSep " \\\n -f " files}
       '';
       script = "echo Ok";
+      unitConfig.ConditionPathExists = bootstrapAddonsPaths;
+    };
+
+    systemd.paths.kube-addon-manager-bootstrap = {
+      wantedBy = [ "kube-addon-manager-bootstrap.service" ];
+      pathConfig = {
+        PathExists = bootstrapAddonsPaths;
+        PathChanged = bootstrapAddonsPaths;
+      };
     };
 
+    services.kubernetes.addonManager.bootstrapAddonsKubeconfig.server = mkDefault top.apiserverAddress;
+
     services.kubernetes.addonManager.bootstrapAddons = mkIf isRBACEnabled
     (let
       name = system:kube-addon-manager;
-- 
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