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-rw-r--r--nixos/modules/services/cluster/kubernetes/kubelet.nix398
1 files changed, 398 insertions, 0 deletions
diff --git a/nixos/modules/services/cluster/kubernetes/kubelet.nix b/nixos/modules/services/cluster/kubernetes/kubelet.nix
new file mode 100644
index 00000000000..af3a5062feb
--- /dev/null
+++ b/nixos/modules/services/cluster/kubernetes/kubelet.nix
@@ -0,0 +1,398 @@
+{ config, lib, options, pkgs, ... }:
+
+with lib;
+
+let
+  top = config.services.kubernetes;
+  otop = options.services.kubernetes;
+  cfg = top.kubelet;
+
+  cniConfig =
+    if cfg.cni.config != [] && cfg.cni.configDir != null then
+      throw "Verbatim CNI-config and CNI configDir cannot both be set."
+    else if cfg.cni.configDir != null then
+      cfg.cni.configDir
+    else
+      (pkgs.buildEnv {
+        name = "kubernetes-cni-config";
+        paths = imap (i: entry:
+          pkgs.writeTextDir "${toString (10+i)}-${entry.type}.conf" (builtins.toJSON entry)
+        ) cfg.cni.config;
+      });
+
+  infraContainer = pkgs.dockerTools.buildImage {
+    name = "pause";
+    tag = "latest";
+    contents = top.package.pause;
+    config.Cmd = ["/bin/pause"];
+  };
+
+  kubeconfig = top.lib.mkKubeConfig "kubelet" cfg.kubeconfig;
+
+  manifestPath = "kubernetes/manifests";
+
+  taintOptions = with lib.types; { name, ... }: {
+    options = {
+      key = mkOption {
+        description = "Key of taint.";
+        default = name;
+        defaultText = literalDocBook "Name of this submodule.";
+        type = str;
+      };
+      value = mkOption {
+        description = "Value of taint.";
+        type = str;
+      };
+      effect = mkOption {
+        description = "Effect of taint.";
+        example = "NoSchedule";
+        type = enum ["NoSchedule" "PreferNoSchedule" "NoExecute"];
+      };
+    };
+  };
+
+  taints = concatMapStringsSep "," (v: "${v.key}=${v.value}:${v.effect}") (mapAttrsToList (n: v: v) cfg.taints);
+in
+{
+  imports = [
+    (mkRemovedOptionModule [ "services" "kubernetes" "kubelet" "applyManifests" ] "")
+    (mkRemovedOptionModule [ "services" "kubernetes" "kubelet" "cadvisorPort" ] "")
+    (mkRemovedOptionModule [ "services" "kubernetes" "kubelet" "allowPrivileged" ] "")
+  ];
+
+  ###### interface
+  options.services.kubernetes.kubelet = with lib.types; {
+
+    address = mkOption {
+      description = "Kubernetes kubelet info server listening address.";
+      default = "0.0.0.0";
+      type = str;
+    };
+
+    clusterDns = mkOption {
+      description = "Use alternative DNS.";
+      default = "10.1.0.1";
+      type = str;
+    };
+
+    clusterDomain = mkOption {
+      description = "Use alternative domain.";
+      default = config.services.kubernetes.addons.dns.clusterDomain;
+      defaultText = literalExpression "config.${options.services.kubernetes.addons.dns.clusterDomain}";
+      type = str;
+    };
+
+    clientCaFile = mkOption {
+      description = "Kubernetes apiserver CA file for client authentication.";
+      default = top.caFile;
+      defaultText = literalExpression "config.${otop.caFile}";
+      type = nullOr path;
+    };
+
+    cni = {
+      packages = mkOption {
+        description = "List of network plugin packages to install.";
+        type = listOf package;
+        default = [];
+      };
+
+      config = mkOption {
+        description = "Kubernetes CNI configuration.";
+        type = listOf attrs;
+        default = [];
+        example = literalExpression ''
+          [{
+            "cniVersion": "0.3.1",
+            "name": "mynet",
+            "type": "bridge",
+            "bridge": "cni0",
+            "isGateway": true,
+            "ipMasq": true,
+            "ipam": {
+                "type": "host-local",
+                "subnet": "10.22.0.0/16",
+                "routes": [
+                    { "dst": "0.0.0.0/0" }
+                ]
+            }
+          } {
+            "cniVersion": "0.3.1",
+            "type": "loopback"
+          }]
+        '';
+      };
+
+      configDir = mkOption {
+        description = "Path to Kubernetes CNI configuration directory.";
+        type = nullOr path;
+        default = null;
+      };
+    };
+
+    containerRuntime = mkOption {
+      description = "Which container runtime type to use";
+      type = enum ["docker" "remote"];
+      default = "remote";
+    };
+
+    containerRuntimeEndpoint = mkOption {
+      description = "Endpoint at which to find the container runtime api interface/socket";
+      type = str;
+      default = "unix:///run/containerd/containerd.sock";
+    };
+
+    enable = mkEnableOption "Kubernetes kubelet.";
+
+    extraOpts = mkOption {
+      description = "Kubernetes kubelet extra command line options.";
+      default = "";
+      type = separatedString " ";
+    };
+
+    featureGates = mkOption {
+      description = "List set of feature gates";
+      default = top.featureGates;
+      defaultText = literalExpression "config.${otop.featureGates}";
+      type = listOf str;
+    };
+
+    healthz = {
+      bind = mkOption {
+        description = "Kubernetes kubelet healthz listening address.";
+        default = "127.0.0.1";
+        type = str;
+      };
+
+      port = mkOption {
+        description = "Kubernetes kubelet healthz port.";
+        default = 10248;
+        type = int;
+      };
+    };
+
+    hostname = mkOption {
+      description = "Kubernetes kubelet hostname override.";
+      default = config.networking.hostName;
+      defaultText = literalExpression "config.networking.hostName";
+      type = str;
+    };
+
+    kubeconfig = top.lib.mkKubeConfigOptions "Kubelet";
+
+    manifests = mkOption {
+      description = "List of manifests to bootstrap with kubelet (only pods can be created as manifest entry)";
+      type = attrsOf attrs;
+      default = {};
+    };
+
+    networkPlugin = mkOption {
+      description = "Network plugin to use by Kubernetes.";
+      type = nullOr (enum ["cni" "kubenet"]);
+      default = "kubenet";
+    };
+
+    nodeIp = mkOption {
+      description = "IP address of the node. If set, kubelet will use this IP address for the node.";
+      default = null;
+      type = nullOr str;
+    };
+
+    registerNode = mkOption {
+      description = "Whether to auto register kubelet with API server.";
+      default = true;
+      type = bool;
+    };
+
+    port = mkOption {
+      description = "Kubernetes kubelet info server listening port.";
+      default = 10250;
+      type = int;
+    };
+
+    seedDockerImages = mkOption {
+      description = "List of docker images to preload on system";
+      default = [];
+      type = listOf package;
+    };
+
+    taints = mkOption {
+      description = "Node taints (https://kubernetes.io/docs/concepts/configuration/assign-pod-node/).";
+      default = {};
+      type = attrsOf (submodule [ taintOptions ]);
+    };
+
+    tlsCertFile = mkOption {
+      description = "File containing x509 Certificate for HTTPS.";
+      default = null;
+      type = nullOr path;
+    };
+
+    tlsKeyFile = mkOption {
+      description = "File containing x509 private key matching tlsCertFile.";
+      default = null;
+      type = nullOr path;
+    };
+
+    unschedulable = mkOption {
+      description = "Whether to set node taint to unschedulable=true as it is the case of node that has only master role.";
+      default = false;
+      type = bool;
+    };
+
+    verbosity = mkOption {
+      description = ''
+        Optional glog verbosity level for logging statements. See
+        <link xlink:href="https://github.com/kubernetes/community/blob/master/contributors/devel/logging.md"/>
+      '';
+      default = null;
+      type = nullOr int;
+    };
+
+  };
+
+  ###### implementation
+  config = mkMerge [
+    (mkIf cfg.enable {
+
+      environment.etc."cni/net.d".source = cniConfig;
+
+      services.kubernetes.kubelet.seedDockerImages = [infraContainer];
+
+      boot.kernel.sysctl = {
+        "net.bridge.bridge-nf-call-iptables"  = 1;
+        "net.ipv4.ip_forward"                 = 1;
+        "net.bridge.bridge-nf-call-ip6tables" = 1;
+      };
+
+      systemd.services.kubelet = {
+        description = "Kubernetes Kubelet Service";
+        wantedBy = [ "kubernetes.target" ];
+        after = [ "containerd.service" "network.target" "kube-apiserver.service" ];
+        path = with pkgs; [
+          gitMinimal
+          openssh
+          util-linux
+          iproute2
+          ethtool
+          thin-provisioning-tools
+          iptables
+          socat
+        ] ++ lib.optional config.boot.zfs.enabled config.boot.zfs.package ++ top.path;
+        preStart = ''
+          ${concatMapStrings (img: ''
+            echo "Seeding container image: ${img}"
+            ${if (lib.hasSuffix "gz" img) then
+              ''${pkgs.gzip}/bin/zcat "${img}" | ${pkgs.containerd}/bin/ctr -n k8s.io image import --all-platforms -''
+            else
+              ''${pkgs.coreutils}/bin/cat "${img}" | ${pkgs.containerd}/bin/ctr -n k8s.io image import --all-platforms -''
+            }
+          '') cfg.seedDockerImages}
+
+          rm /opt/cni/bin/* || true
+          ${concatMapStrings (package: ''
+            echo "Linking cni package: ${package}"
+            ln -fs ${package}/bin/* /opt/cni/bin
+          '') cfg.cni.packages}
+        '';
+        serviceConfig = {
+          Slice = "kubernetes.slice";
+          CPUAccounting = true;
+          MemoryAccounting = true;
+          Restart = "on-failure";
+          RestartSec = "1000ms";
+          ExecStart = ''${top.package}/bin/kubelet \
+            --address=${cfg.address} \
+            --authentication-token-webhook \
+            --authentication-token-webhook-cache-ttl="10s" \
+            --authorization-mode=Webhook \
+            ${optionalString (cfg.clientCaFile != null)
+              "--client-ca-file=${cfg.clientCaFile}"} \
+            ${optionalString (cfg.clusterDns != "")
+              "--cluster-dns=${cfg.clusterDns}"} \
+            ${optionalString (cfg.clusterDomain != "")
+              "--cluster-domain=${cfg.clusterDomain}"} \
+            --cni-conf-dir=${cniConfig} \
+            ${optionalString (cfg.featureGates != [])
+              "--feature-gates=${concatMapStringsSep "," (feature: "${feature}=true") cfg.featureGates}"} \
+            --hairpin-mode=hairpin-veth \
+            --healthz-bind-address=${cfg.healthz.bind} \
+            --healthz-port=${toString cfg.healthz.port} \
+            --hostname-override=${cfg.hostname} \
+            --kubeconfig=${kubeconfig} \
+            ${optionalString (cfg.networkPlugin != null)
+              "--network-plugin=${cfg.networkPlugin}"} \
+            ${optionalString (cfg.nodeIp != null)
+              "--node-ip=${cfg.nodeIp}"} \
+            --pod-infra-container-image=pause \
+            ${optionalString (cfg.manifests != {})
+              "--pod-manifest-path=/etc/${manifestPath}"} \
+            --port=${toString cfg.port} \
+            --register-node=${boolToString cfg.registerNode} \
+            ${optionalString (taints != "")
+              "--register-with-taints=${taints}"} \
+            --root-dir=${top.dataDir} \
+            ${optionalString (cfg.tlsCertFile != null)
+              "--tls-cert-file=${cfg.tlsCertFile}"} \
+            ${optionalString (cfg.tlsKeyFile != null)
+              "--tls-private-key-file=${cfg.tlsKeyFile}"} \
+            ${optionalString (cfg.verbosity != null) "--v=${toString cfg.verbosity}"} \
+            --container-runtime=${cfg.containerRuntime} \
+            --container-runtime-endpoint=${cfg.containerRuntimeEndpoint} \
+            --cgroup-driver=systemd \
+            ${cfg.extraOpts}
+          '';
+          WorkingDirectory = top.dataDir;
+        };
+        unitConfig = {
+          StartLimitIntervalSec = 0;
+        };
+      };
+
+      # Allways include cni plugins
+      services.kubernetes.kubelet.cni.packages = [pkgs.cni-plugins pkgs.cni-plugin-flannel];
+
+      boot.kernelModules = ["br_netfilter" "overlay"];
+
+      services.kubernetes.kubelet.hostname = with config.networking;
+        mkDefault (hostName + optionalString (domain != null) ".${domain}");
+
+      services.kubernetes.pki.certs = with top.lib; {
+        kubelet = mkCert {
+          name = "kubelet";
+          CN = top.kubelet.hostname;
+          action = "systemctl restart kubelet.service";
+
+        };
+        kubeletClient = mkCert {
+          name = "kubelet-client";
+          CN = "system:node:${top.kubelet.hostname}";
+          fields = {
+            O = "system:nodes";
+          };
+          action = "systemctl restart kubelet.service";
+        };
+      };
+
+      services.kubernetes.kubelet.kubeconfig.server = mkDefault top.apiserverAddress;
+    })
+
+    (mkIf (cfg.enable && cfg.manifests != {}) {
+      environment.etc = mapAttrs' (name: manifest:
+        nameValuePair "${manifestPath}/${name}.json" {
+          text = builtins.toJSON manifest;
+          mode = "0755";
+        }
+      ) cfg.manifests;
+    })
+
+    (mkIf (cfg.unschedulable && cfg.enable) {
+      services.kubernetes.kubelet.taints.unschedulable = {
+        value = "true";
+        effect = "NoSchedule";
+      };
+    })
+
+  ];
+
+  meta.buildDocsInSandbox = false;
+}