diff options
Diffstat (limited to 'nixos/modules/services/cluster/kubernetes/pki.nix')
| -rw-r--r-- | nixos/modules/services/cluster/kubernetes/pki.nix | 406 |
1 files changed, 406 insertions, 0 deletions
diff --git a/nixos/modules/services/cluster/kubernetes/pki.nix b/nixos/modules/services/cluster/kubernetes/pki.nix new file mode 100644 index 00000000000..7d9198d20e8 --- /dev/null +++ b/nixos/modules/services/cluster/kubernetes/pki.nix @@ -0,0 +1,406 @@ +{ config, lib, pkgs, ... }: + +with lib; + +let + top = config.services.kubernetes; + cfg = top.pki; + + csrCA = pkgs.writeText "kube-pki-cacert-csr.json" (builtins.toJSON { + key = { + algo = "rsa"; + size = 2048; + }; + names = singleton cfg.caSpec; + }); + + csrCfssl = pkgs.writeText "kube-pki-cfssl-csr.json" (builtins.toJSON { + key = { + algo = "rsa"; + size = 2048; + }; + CN = top.masterAddress; + hosts = [top.masterAddress] ++ cfg.cfsslAPIExtraSANs; + }); + + cfsslAPITokenBaseName = "apitoken.secret"; + cfsslAPITokenPath = "${config.services.cfssl.dataDir}/${cfsslAPITokenBaseName}"; + certmgrAPITokenPath = "${top.secretsPath}/${cfsslAPITokenBaseName}"; + cfsslAPITokenLength = 32; + + clusterAdminKubeconfig = with cfg.certs.clusterAdmin; + top.lib.mkKubeConfig "cluster-admin" { + server = top.apiserverAddress; + certFile = cert; + keyFile = key; + }; + + remote = with config.services; "https://${kubernetes.masterAddress}:${toString cfssl.port}"; +in +{ + ###### interface + options.services.kubernetes.pki = with lib.types; { + + enable = mkEnableOption "easyCert issuer service"; + + certs = mkOption { + description = "List of certificate specs to feed to cert generator."; + default = {}; + type = attrs; + }; + + genCfsslCACert = mkOption { + description = '' + Whether to automatically generate cfssl CA certificate and key, + if they don't exist. + ''; + default = true; + type = bool; + }; + + genCfsslAPICerts = mkOption { + description = '' + Whether to automatically generate cfssl API webserver TLS cert and key, + if they don't exist. + ''; + default = true; + type = bool; + }; + + cfsslAPIExtraSANs = mkOption { + description = '' + Extra x509 Subject Alternative Names to be added to the cfssl API webserver TLS cert. + ''; + default = []; + example = [ "subdomain.example.com" ]; + type = listOf str; + }; + + genCfsslAPIToken = mkOption { + description = '' + Whether to automatically generate cfssl API-token secret, + if they doesn't exist. + ''; + default = true; + type = bool; + }; + + pkiTrustOnBootstrap = mkOption { + description = "Whether to always trust remote cfssl server upon initial PKI bootstrap."; + default = true; + type = bool; + }; + + caCertPathPrefix = mkOption { + description = '' + Path-prefrix for the CA-certificate to be used for cfssl signing. + Suffixes ".pem" and "-key.pem" will be automatically appended for + the public and private keys respectively. + ''; + default = "${config.services.cfssl.dataDir}/ca"; + defaultText = literalExpression ''"''${config.services.cfssl.dataDir}/ca"''; + type = str; + }; + + caSpec = mkOption { + description = "Certificate specification for the auto-generated CAcert."; + default = { + CN = "kubernetes-cluster-ca"; + O = "NixOS"; + OU = "services.kubernetes.pki.caSpec"; + L = "auto-generated"; + }; + type = attrs; + }; + + etcClusterAdminKubeconfig = mkOption { + description = '' + Symlink a kubeconfig with cluster-admin privileges to environment path + (/etc/<path>). + ''; + default = null; + type = nullOr str; + }; + + }; + + ###### implementation + config = mkIf cfg.enable + (let + cfsslCertPathPrefix = "${config.services.cfssl.dataDir}/cfssl"; + cfsslCert = "${cfsslCertPathPrefix}.pem"; + cfsslKey = "${cfsslCertPathPrefix}-key.pem"; + in + { + + services.cfssl = mkIf (top.apiserver.enable) { + enable = true; + address = "0.0.0.0"; + tlsCert = cfsslCert; + tlsKey = cfsslKey; + configFile = toString (pkgs.writeText "cfssl-config.json" (builtins.toJSON { + signing = { + profiles = { + default = { + usages = ["digital signature"]; + auth_key = "default"; + expiry = "720h"; + }; + }; + }; + auth_keys = { + default = { + type = "standard"; + key = "file:${cfsslAPITokenPath}"; + }; + }; + })); + }; + + systemd.services.cfssl.preStart = with pkgs; with config.services.cfssl; mkIf (top.apiserver.enable) + (concatStringsSep "\n" [ + "set -e" + (optionalString cfg.genCfsslCACert '' + if [ ! -f "${cfg.caCertPathPrefix}.pem" ]; then + ${cfssl}/bin/cfssl genkey -initca ${csrCA} | \ + ${cfssl}/bin/cfssljson -bare ${cfg.caCertPathPrefix} + fi + '') + (optionalString cfg.genCfsslAPICerts '' + if [ ! -f "${dataDir}/cfssl.pem" ]; then + ${cfssl}/bin/cfssl gencert -ca "${cfg.caCertPathPrefix}.pem" -ca-key "${cfg.caCertPathPrefix}-key.pem" ${csrCfssl} | \ + ${cfssl}/bin/cfssljson -bare ${cfsslCertPathPrefix} + fi + '') + (optionalString cfg.genCfsslAPIToken '' + if [ ! -f "${cfsslAPITokenPath}" ]; then + head -c ${toString (cfsslAPITokenLength / 2)} /dev/urandom | od -An -t x | tr -d ' ' >"${cfsslAPITokenPath}" + fi + chown cfssl "${cfsslAPITokenPath}" && chmod 400 "${cfsslAPITokenPath}" + '')]); + + systemd.services.kube-certmgr-bootstrap = { + description = "Kubernetes certmgr bootstrapper"; + wantedBy = [ "certmgr.service" ]; + after = [ "cfssl.target" ]; + script = concatStringsSep "\n" ['' + set -e + + # If there's a cfssl (cert issuer) running locally, then don't rely on user to + # manually paste it in place. Just symlink. + # otherwise, create the target file, ready for users to insert the token + + mkdir -p "$(dirname "${certmgrAPITokenPath}")" + if [ -f "${cfsslAPITokenPath}" ]; then + ln -fs "${cfsslAPITokenPath}" "${certmgrAPITokenPath}" + else + touch "${certmgrAPITokenPath}" && chmod 600 "${certmgrAPITokenPath}" + fi + '' + (optionalString (cfg.pkiTrustOnBootstrap) '' + if [ ! -f "${top.caFile}" ] || [ $(cat "${top.caFile}" | wc -c) -lt 1 ]; then + ${pkgs.curl}/bin/curl --fail-early -f -kd '{}' ${remote}/api/v1/cfssl/info | \ + ${pkgs.cfssl}/bin/cfssljson -stdout >${top.caFile} + fi + '') + ]; + serviceConfig = { + RestartSec = "10s"; + Restart = "on-failure"; + }; + }; + + services.certmgr = { + enable = true; + package = pkgs.certmgr-selfsigned; + svcManager = "command"; + specs = + let + mkSpec = _: cert: { + inherit (cert) action; + authority = { + inherit remote; + file.path = cert.caCert; + root_ca = cert.caCert; + profile = "default"; + auth_key_file = certmgrAPITokenPath; + }; + certificate = { + path = cert.cert; + }; + private_key = cert.privateKeyOptions; + request = { + hosts = [cert.CN] ++ cert.hosts; + inherit (cert) CN; + key = { + algo = "rsa"; + size = 2048; + }; + names = [ cert.fields ]; + }; + }; + in + mapAttrs mkSpec cfg.certs; + }; + + #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 = mkIf top.addonManager.enable (mkMerge [{ + environment.KUBECONFIG = with cfg.certs.addonManager; + top.lib.mkKubeConfig "addon-manager" { + server = top.apiserverAddress; + certFile = cert; + keyFile = key; + }; + } + + (optionalAttrs (top.addonManager.bootstrapAddons != {}) { + serviceConfig.PermissionsStartOnly = true; + preStart = with pkgs; + let + files = mapAttrsToList (n: v: writeText "${n}.json" (builtins.toJSON v)) + top.addonManager.bootstrapAddons; + in + '' + export KUBECONFIG=${clusterAdminKubeconfig} + ${kubernetes}/bin/kubectl apply -f ${concatStringsSep " \\\n -f " files} + ''; + })]); + + environment.etc.${cfg.etcClusterAdminKubeconfig}.source = mkIf (!isNull cfg.etcClusterAdminKubeconfig) + clusterAdminKubeconfig; + + environment.systemPackages = mkIf (top.kubelet.enable || top.proxy.enable) [ + (pkgs.writeScriptBin "nixos-kubernetes-node-join" '' + set -e + exec 1>&2 + + if [ $# -gt 0 ]; then + echo "Usage: $(basename $0)" + echo "" + echo "No args. Apitoken must be provided on stdin." + echo "To get the apitoken, execute: 'sudo cat ${certmgrAPITokenPath}' on the master node." + exit 1 + fi + + if [ $(id -u) != 0 ]; then + echo "Run as root please." + exit 1 + fi + + read -r token + if [ ''${#token} != ${toString cfsslAPITokenLength} ]; then + echo "Token must be of length ${toString cfsslAPITokenLength}." + exit 1 + fi + + echo $token > ${certmgrAPITokenPath} + chmod 600 ${certmgrAPITokenPath} + + echo "Restarting certmgr..." >&1 + systemctl restart certmgr + + echo "Waiting for certs to appear..." >&1 + + ${optionalString top.kubelet.enable '' + while [ ! -f ${cfg.certs.kubelet.cert} ]; do sleep 1; done + echo "Restarting kubelet..." >&1 + systemctl restart kubelet + ''} + + ${optionalString top.proxy.enable '' + while [ ! -f ${cfg.certs.kubeProxyClient.cert} ]; do sleep 1; done + echo "Restarting kube-proxy..." >&1 + systemctl restart kube-proxy + ''} + + ${optionalString top.flannel.enable '' + while [ ! -f ${cfg.certs.flannelClient.cert} ]; do sleep 1; done + echo "Restarting flannel..." >&1 + systemctl restart flannel + ''} + + echo "Node joined succesfully" + '')]; + + # isolate etcd on loopback at the master node + # easyCerts doesn't support multimaster clusters anyway atm. + services.etcd = with cfg.certs.etcd; { + listenClientUrls = ["https://127.0.0.1:2379"]; + listenPeerUrls = ["https://127.0.0.1:2380"]; + advertiseClientUrls = ["https://etcd.local:2379"]; + initialCluster = ["${top.masterAddress}=https://etcd.local:2380"]; + initialAdvertisePeerUrls = ["https://etcd.local:2380"]; + certFile = mkDefault cert; + keyFile = mkDefault key; + trustedCaFile = mkDefault caCert; + }; + networking.extraHosts = mkIf (config.services.etcd.enable) '' + 127.0.0.1 etcd.${top.addons.dns.clusterDomain} etcd.local + ''; + + services.flannel = with cfg.certs.flannelClient; { + kubeconfig = top.lib.mkKubeConfig "flannel" { + server = top.apiserverAddress; + certFile = cert; + keyFile = key; + }; + }; + + services.kubernetes = { + + apiserver = mkIf top.apiserver.enable (with cfg.certs.apiServer; { + etcd = with cfg.certs.apiserverEtcdClient; { + servers = ["https://etcd.local:2379"]; + certFile = mkDefault cert; + keyFile = mkDefault key; + caFile = mkDefault caCert; + }; + clientCaFile = mkDefault caCert; + tlsCertFile = mkDefault cert; + tlsKeyFile = mkDefault key; + serviceAccountKeyFile = mkDefault cfg.certs.serviceAccount.cert; + serviceAccountSigningKeyFile = mkDefault cfg.certs.serviceAccount.key; + kubeletClientCaFile = mkDefault caCert; + kubeletClientCertFile = mkDefault cfg.certs.apiserverKubeletClient.cert; + kubeletClientKeyFile = mkDefault cfg.certs.apiserverKubeletClient.key; + proxyClientCertFile = mkDefault cfg.certs.apiserverProxyClient.cert; + proxyClientKeyFile = mkDefault cfg.certs.apiserverProxyClient.key; + }); + controllerManager = mkIf top.controllerManager.enable { + serviceAccountKeyFile = mkDefault cfg.certs.serviceAccount.key; + rootCaFile = cfg.certs.controllerManagerClient.caCert; + kubeconfig = with cfg.certs.controllerManagerClient; { + certFile = mkDefault cert; + keyFile = mkDefault key; + }; + }; + scheduler = mkIf top.scheduler.enable { + kubeconfig = with cfg.certs.schedulerClient; { + certFile = mkDefault cert; + keyFile = mkDefault key; + }; + }; + kubelet = mkIf top.kubelet.enable { + clientCaFile = mkDefault cfg.certs.kubelet.caCert; + tlsCertFile = mkDefault cfg.certs.kubelet.cert; + tlsKeyFile = mkDefault cfg.certs.kubelet.key; + kubeconfig = with cfg.certs.kubeletClient; { + certFile = mkDefault cert; + keyFile = mkDefault key; + }; + }; + proxy = mkIf top.proxy.enable { + kubeconfig = with cfg.certs.kubeProxyClient; { + certFile = mkDefault cert; + keyFile = mkDefault key; + }; + }; + }; + }); + + meta.buildDocsInSandbox = false; +} |