nixpkgs/nixos/modules/services/cluster/kubernetes/flannel.nix
2019-09-08 23:38:31 +00:00

134 lines
3.5 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
top = config.services.kubernetes;
cfg = top.flannel;
# we want flannel to use kubernetes itself as configuration backend, not direct etcd
storageBackend = "kubernetes";
# needed for flannel to pass options to docker
mkDockerOpts = pkgs.runCommand "mk-docker-opts" {
buildInputs = [ pkgs.makeWrapper ];
} ''
mkdir -p $out
# bashInteractive needed for `compgen`
makeWrapper ${pkgs.bashInteractive}/bin/bash $out/mk-docker-opts --add-flags "${pkgs.kubernetes}/bin/mk-docker-opts.sh"
'';
in
{
###### interface
options.services.kubernetes.flannel = {
enable = mkEnableOption "enable flannel networking";
};
###### implementation
config = mkIf cfg.enable {
services.flannel = {
enable = mkDefault true;
network = mkDefault top.clusterCidr;
inherit storageBackend;
nodeName = config.services.kubernetes.kubelet.hostname;
};
services.kubernetes.kubelet = {
networkPlugin = mkDefault "cni";
cni.config = mkDefault [{
name = "mynet";
type = "flannel";
delegate = {
isDefaultGateway = true;
bridge = "docker0";
};
}];
};
systemd.services.mk-docker-opts = {
description = "Pre-Docker Actions";
path = with pkgs; [ gawk gnugrep ];
script = ''
${mkDockerOpts}/mk-docker-opts -d /run/flannel/docker
systemctl restart docker
'';
serviceConfig.Type = "oneshot";
};
systemd.paths.flannel-subnet-env = {
wantedBy = [ "flannel.service" ];
pathConfig = {
PathModified = "/run/flannel/subnet.env";
Unit = "mk-docker-opts.service";
};
};
systemd.services.docker = {
environment.DOCKER_OPTS = "-b none";
serviceConfig.EnvironmentFile = "-/run/flannel/docker";
};
# read environment variables generated by mk-docker-opts
virtualisation.docker.extraOptions = "$DOCKER_OPTS";
networking = {
firewall.allowedUDPPorts = [
8285 # flannel udp
8472 # flannel vxlan
];
dhcpcd.denyInterfaces = [ "docker*" "flannel*" ];
};
services.kubernetes.pki.certs = {
flannelClient = top.lib.mkCert {
name = "flannel-client";
CN = "flannel-client";
action = "systemctl restart flannel.service";
};
};
# 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";
metadata = { name = "flannel"; };
rules = [{
apiGroups = [ "" ];
resources = [ "pods" ];
verbs = [ "get" ];
}
{
apiGroups = [ "" ];
resources = [ "nodes" ];
verbs = [ "list" "watch" ];
}
{
apiGroups = [ "" ];
resources = [ "nodes/status" ];
verbs = [ "patch" ];
}];
};
flannel-crb = {
apiVersion = "rbac.authorization.k8s.io/v1beta1";
kind = "ClusterRoleBinding";
metadata = { name = "flannel"; };
roleRef = {
apiGroup = "rbac.authorization.k8s.io";
kind = "ClusterRole";
name = "flannel";
};
subjects = [{
kind = "User";
name = "flannel-client";
}];
};
};
};
}