Merge pull request #44556 from johanot/certmgr-module-init

nixos/certmgr: init

nixos/modules/module-list.nix

···
   ./services/search/hound.nix
   ./services/search/kibana.nix
   ./services/search/solr.nix
+  ./services/security/certmgr.nix
   ./services/security/cfssl.nix
   ./services/security/clamav.nix
   ./services/security/fail2ban.nix

nixos/modules/services/security/certmgr.nix

···
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.certmgr;
+
+  specs = mapAttrsToList (n: v: rec {
+    name = n + ".json";
+    path = if isAttrs v then pkgs.writeText name (builtins.toJSON v) else v;
+  }) cfg.specs;
+
+  allSpecs = pkgs.linkFarm "certmgr.d" specs;
+
+  certmgrYaml = pkgs.writeText "certmgr.yaml" (builtins.toJSON {
+    dir = allSpecs;
+    default_remote = cfg.defaultRemote;
+    svcmgr = cfg.svcManager;
+    before = cfg.validMin;
+    interval = cfg.renewInterval;
+    inherit (cfg) metricsPort metricsAddress;
+  });
+
+  specPaths = map dirOf (concatMap (spec:
+    if isAttrs spec then
+      collect isString (filterAttrsRecursive (n: v: isAttrs v || n == "path") spec)
+    else
+      [ spec ]
+  ) (attrValues cfg.specs));
+
+  preStart = ''
+    ${concatStringsSep " \\\n" (["mkdir -p"] ++ map escapeShellArg specPaths)}
+    ${pkgs.certmgr}/bin/certmgr -f ${certmgrYaml} check
+  '';
+in
+{
+  options.services.certmgr = {
+    enable = mkEnableOption "certmgr";
+
+    defaultRemote = mkOption {
+      type = types.str;
+      default = "127.0.0.1:8888";
+      description = "The default CA host:port to use.";
+    };
+
+    validMin = mkOption {
+      default = "72h";
+      type = types.str;
+      description = "The interval before a certificate expires to start attempting to renew it.";
+    };
+
+    renewInterval = mkOption {
+      default = "30m";
+      type = types.str;
+      description = "How often to check certificate expirations and how often to update the cert_next_expires metric.";
+    };
+
+    metricsAddress = mkOption {
+      default = "127.0.0.1";
+      type = types.str;
+      description = "The address for the Prometheus HTTP endpoint.";
+    };
+
+    metricsPort = mkOption {
+      default = 9488;
+      type = types.ints.u16;
+      description = "The port for the Prometheus HTTP endpoint.";
+    };
+
+    specs = mkOption {
+      default = {};
+      example = literalExample ''
+      {
+        exampleCert =
+        let
+          domain = "example.com";
+          secret = name: "/var/lib/secrets/''${name}.pem";
+        in {
+          service = "nginx";
+          action = "reload";
+          authority = {
+            file.path = secret "ca";
+          };
+          certificate = {
+            path = secret domain;
+          };
+          private_key = {
+            owner = "root";
+            group = "root";
+            mode = "0600";
+            path = secret "''${domain}-key";
+          };
+          request = {
+            CN = domain;
+            hosts = [ "mail.''${domain}" "www.''${domain}" ];
+            key = {
+              algo = "rsa";
+              size = 2048;
+            };
+            names = {
+              O = "Example Organization";
+              C = "USA";
+            };
+          };
+        };
+        otherCert = "/var/certmgr/specs/other-cert.json";
+      }
+      '';
+      type = with types; attrsOf (either (submodule {
+        options = {
+          service = mkOption {
+            type = nullOr str;
+            default = null;
+            description = "The service on which to perform <action> after fetching.";
+          };
+
+          action = mkOption {
+            type = addCheck str (x: cfg.svcManager == "command" || elem x ["restart" "reload" "nop"]);
+            default = "nop";
+            description = "The action to take after fetching.";
+          };
+
+          # These ought all to be specified according to certmgr spec def.
+          authority = mkOption {
+            type = attrs;
+            description = "certmgr spec authority object.";
+          };
+
+          certificate = mkOption {
+            type = nullOr attrs;
+            description = "certmgr spec certificate object.";
+          };
+
+          private_key = mkOption {
+            type = nullOr attrs;
+            description = "certmgr spec private_key object.";
+          };
+
+          request = mkOption {
+            type = nullOr attrs;
+            description = "certmgr spec request object.";
+          };
+        };
+    }) path);
+      description = ''
+        Certificate specs as described by:
+        <link xlink:href="https://github.com/cloudflare/certmgr#certificate-specs" />
+        These will be added to the Nix store, so they will be world readable.
+      '';
+    };
+
+    svcManager = mkOption {
+      default = "systemd";
+      type = types.enum [ "circus" "command" "dummy" "openrc" "systemd" "sysv" ];
+      description = ''
+        This specifies the service manager to use for restarting or reloading services.
+        See: <link xlink:href="https://github.com/cloudflare/certmgr#certmgryaml" />.
+        For how to use the "command" service manager in particular,
+        see: <link xlink:href="https://github.com/cloudflare/certmgr#command-svcmgr-and-how-to-use-it" />.
+      '';
+    };
+
+  };
+
+  config = mkIf cfg.enable {
+    assertions = [
+      {
+        assertion = cfg.specs != {};
+        message = "Certmgr specs cannot be empty.";
+      }
+      {
+        assertion = !any (hasAttrByPath [ "authority" "auth_key" ]) (attrValues cfg.specs);
+        message = ''
+          Inline services.certmgr.specs are added to the Nix store rendering them world readable.
+          Specify paths as specs, if you want to use include auth_key - or use the auth_key_file option."
+        '';
+      }
+    ];
+
+    systemd.services.certmgr = {
+      description = "certmgr";
+      path = mkIf (cfg.svcManager == "command") [ pkgs.bash ];
+      after = [ "network-online.target" ];
+      wantedBy = [ "multi-user.target" ];
+      inherit preStart;
+
+      serviceConfig = {
+        Restart = "always";
+        RestartSec = "10s";
+        ExecStart = "${pkgs.certmgr}/bin/certmgr -f ${certmgrYaml}";
+      };
+    };
+  };
+}

nixos/release.nix

···
   tests.buildbot = callTest tests/buildbot.nix {};
   tests.cadvisor = callTestOnMatchingSystems ["x86_64-linux"] tests/cadvisor.nix {};
   tests.ceph = callTestOnMatchingSystems ["x86_64-linux"] tests/ceph.nix {};
+  tests.certmgr = callSubTests tests/certmgr.nix {};
   tests.cfssl = callTestOnMatchingSystems ["x86_64-linux"] tests/cfssl.nix {};
   tests.chromium = (callSubTestsOnMatchingSystems ["x86_64-linux"] tests/chromium.nix {}).stable or {};
   tests.cjdns = callTest tests/cjdns.nix {};

nixos/tests/certmgr.nix

···
+{ system ? builtins.currentSystem }:
+
+with import ../lib/testing.nix { inherit system; };
+let
+  mkSpec = { host, service ? null, action }: {
+    inherit action;
+    authority = {
+      file = {
+        group = "nobody";
+        owner = "nobody";
+        path = "/tmp/${host}-ca.pem";
+      };
+      label = "www_ca";
+      profile = "three-month";
+      remote = "localhost:8888";
+    };
+    certificate = {
+      group = "nobody";
+      owner = "nobody";
+      path = "/tmp/${host}-cert.pem";
+    };
+    private_key = {
+      group = "nobody";
+      mode = "0600";
+      owner = "nobody";
+      path = "/tmp/${host}-key.pem";
+    };
+    request = {
+      CN = host;
+      hosts = [ host "www.${host}" ];
+      key = {
+        algo = "rsa";
+        size = 2048;
+      };
+      names = [
+        {
+          C = "US";
+          L = "San Francisco";
+          O = "Example, LLC";
+          ST = "CA";
+        }
+      ];
+    };
+    inherit service;
+  };
+
+  mkCertmgrTest = { svcManager, specs, testScript }: makeTest {
+    name = "certmgr-" + svcManager;
+    nodes = {
+      machine = { config, lib, pkgs, ... }: {
+        networking.firewall.allowedTCPPorts = with config.services; [ cfssl.port certmgr.metricsPort ];
+        networking.extraHosts = "127.0.0.1 imp.example.org decl.example.org";
+
+        services.cfssl.enable = true;
+        systemd.services.cfssl.after = [ "cfssl-init.service" "networking.target" ];
+
+        systemd.services.cfssl-init = {
+          description = "Initialize the cfssl CA";
+          wantedBy    = [ "multi-user.target" ];
+          serviceConfig = {
+            User             = "cfssl";
+            Type             = "oneshot";
+            WorkingDirectory = config.services.cfssl.dataDir;
+          };
+          script = ''
+            ${pkgs.cfssl}/bin/cfssl genkey -initca ${pkgs.writeText "ca.json" (builtins.toJSON {
+              hosts = [ "ca.example.com" ];
+              key = {
+                algo = "rsa"; size = 4096; };
+                names = [
+                  {
+                    C = "US";
+                    L = "San Francisco";
+                    O = "Internet Widgets, LLC";
+                    OU = "Certificate Authority";
+                    ST = "California";
+                  }
+                ];
+            })} | ${pkgs.cfssl}/bin/cfssljson -bare ca
+          '';
+        };
+
+        services.nginx = {
+          enable = true;
+          virtualHosts = lib.mkMerge (map (host: {
+            ${host} = {
+              sslCertificate = "/tmp/${host}-cert.pem";
+              sslCertificateKey = "/tmp/${host}-key.pem";
+              extraConfig = ''
+                ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
+              '';
+              onlySSL = true;
+              serverName = host;
+              root = pkgs.writeTextDir "index.html" "It works!";
+            };
+          }) [ "imp.example.org" "decl.example.org" ]);
+        };
+
+        systemd.services.nginx.wantedBy = lib.mkForce [];
+
+        systemd.services.certmgr.after = [ "cfssl.service" ];
+        services.certmgr = {
+          enable = true;
+          inherit svcManager;
+          inherit specs;
+        };
+
+      };
+    };
+    inherit testScript;
+  };
+in
+{
+  systemd = mkCertmgrTest {
+    svcManager = "systemd";
+    specs = {
+      decl = mkSpec { host = "decl.example.org"; service = "nginx"; action ="restart"; };
+      imp = toString (pkgs.writeText "test.json" (builtins.toJSON (
+        mkSpec { host = "imp.example.org"; service = "nginx"; action = "restart"; }
+      )));
+    };
+    testScript = ''
+      $machine->waitForUnit('cfssl.service');
+      $machine->waitUntilSucceeds('ls /tmp/decl.example.org-ca.pem');
+      $machine->waitUntilSucceeds('ls /tmp/decl.example.org-key.pem');
+      $machine->waitUntilSucceeds('ls /tmp/decl.example.org-cert.pem');
+      $machine->waitUntilSucceeds('ls /tmp/imp.example.org-ca.pem');
+      $machine->waitUntilSucceeds('ls /tmp/imp.example.org-key.pem');
+      $machine->waitUntilSucceeds('ls /tmp/imp.example.org-cert.pem');
+      $machine->waitForUnit('nginx.service');
+      $machine->succeed('[ "1" -lt "$(journalctl -u nginx | grep "Starting Nginx" | wc -l)" ]');
+      $machine->succeed('curl --cacert /tmp/imp.example.org-ca.pem https://imp.example.org');
+      $machine->succeed('curl --cacert /tmp/decl.example.org-ca.pem https://decl.example.org');
+    '';
+  };
+
+  command = mkCertmgrTest {
+    svcManager = "command";
+    specs = {
+      test = mkSpec { host = "command.example.org"; action = "touch /tmp/command.executed"; };
+    };
+    testScript = ''
+      $machine->waitForUnit('cfssl.service');
+      $machine->waitUntilSucceeds('stat /tmp/command.executed');
+    '';
+  };
+
+}