git.delta.rocks / jrsonnet / refs/commits / 05b4cf076c7f

{config, ...}: {
  secrets = let ownership = { owner = "gitlab"; group = "gitlab"; }; in {
    gitlab-initial-root = {
      generator = {mkPassword}: mkPassword {};
    } // ownership;
    gitlab-secret = {
      generator = {mkPassword}: mkPassword {};
    } // ownership;
    gitlab-otp = {
      generator = {mkPassword}: mkPassword {};
    } // ownership;
    gitlab-db = {
      generator = {mkPassword}: mkPassword {};
    } // ownership;
    gitlab-jws = {
      generator = {mkRsa}: mkRsa {};
    } // ownership;
  };
  services.gitlab = let secrets = config.secrets; in {
    enable = true;
    initialRootPasswordFile = secrets.gitlab-initial-root.secretPath;
    secrets = {
      secretFile = secrets.gitlab-secret.secretPath;
      otpFile = secrets.gitlab-otp.secretPath;
      dbFile = secrets.gitlab-db.secretPath;
      jwsFile = secrets.gitlab-jws.secretPath;
    };
  };
}

{...}: {
  # First I define required secret generators:
  nixpkgs.overlays = [
    (final: prev: let
      lib = final.lib;
    in {
      readKubernetesCa = {impureOn}:
        final.mkImpureSecretGenerator ''
          cd ~/ca

          cert=kubernetes-intermediateCA.crt

          expires_at=$(openssl x509 -in $cert -noout -enddate | cut -d= -f2 | xargs -I{} date -u -d {} +"%Y-%m-%dT%H:%M:%S.%NZ")
          echo -n $expires_at > $out/expires_at

          cat $cert > $out/public
        ''
        impureOn;
      mkKubernetesCert = {
        subj,
        sans ? [],
        impureOn,
      }:
        final.mkImpureSecretGenerator ''
          cd ~/ca

          params=$(sudo mktemp)
          csr=$(sudo mktemp)
          cert=$(sudo mktemp)
          sudo openssl ecparam -genkey -name secp384r1 -out $params
          sudo openssl req -new -key $params \
            -subj "${lib.strings.concatStringsSep "" (lib.attrsets.mapAttrsToList (k: v: "/${k}=${v}") subj)}" \
            ${lib.optionalString (sans != []) "-addext \"subjectAltName = ${lib.strings.concatStringsSep "," sans}\""} \
            -out $csr
          sudo hsms x509 -req -days 365 -in $csr -CA kubernetes-intermediateCA.crt -CAkey "pkcs11:object=[CENSORED] Kubernetes Intermediate CA;type=private" -CAcreateserial -copy_extensions copy -out $cert

          expires_at=$(sudo openssl x509 -in $cert -noout -enddate | cut -d= -f2 | xargs -I{} date -u -d {} +"%Y-%m-%dT%H:%M:%S.%NZ")
          echo -n $expires_at > $out/expires_at

          sudo cat $params | encrypt > $out/secret
          sudo cat $cert > $out/public
        ''
        impureOn;
    })
  ];
  # Those secret generators are impure, thus they are run in system environment.
  # Probably there needs to be a dedicated user for that kind of tasks, but this is my current setup, don't judge.
  # I write a couple of scripts for executing openssl with HSM.
  environment.systemPackages = [
    pkgs.openssl.bin
    (pkgs.writeShellApplication {
      name = "hsms";
      text = ''
        set -eu
        export OPENSSL_CONF=${openssl-conf}
        # Yay, using secrets to generate secrets!
        HSM_PIN=$(cat ${config.secrets.hsm-pin.secretPath})
        exec ${pkgs.openssl}/bin/openssl "$@" -keyform=engine -CAkeyform=engine -engine=pkcs11 -passin=pass:"$HSM_PIN"
      '';
    })
    (pkgs.writeShellApplication {
      name = "hsmt";
      text = ''
        set -eu
        HSM_PIN=$(cat ${config.secrets.hsm-pin.secretPath})
        exec ${pkgs.opensc}/bin/pkcs11-tool -l --pin="$HSM_PIN" "$@"
      '';
    })
  ];
  # And finally, I have secrets, which are shared between machines.
  # Note that this example is somewhat wrong, as this goes not into the machine configuration, but to fleet configuration.
  sharedSecrets = {
    "ca.pem" = {
      # This is just the public key, no need to regenerate it to change owner list
      regenerateOnOwnerAdded = false;
      # For secret regeneration/reencryption, we need to specify which machines SHOULD have it.
      expectedOwners = ["controlplane-1" "controlplane-2" "worker-1" "worker-2"];
      generator = {readKubernetesCa}:
        readKubernetesCa {
          impureOn = "[CENSORED]";
        };
    };
    "kube-admin.pem" = {
      regenerateOnOwnerAdded = false;
      expectedOwners = ["cluster-admin"];
      generator = {mkKubernetesCert}:
        mkKubernetesCert {
          subj = {
            CN = "admin";
            O = "system:masters";
          };
          impureOn = "[CENSORED]";
        };
    };
    "kube-apiserver.pem" = {
      # This secret depends on machine SANS, so if owner list has been changed, then we need to regenerate it.
      # However, SANS dependency is in fact handled by secret seed, and secret is regenerated if the seed is changed...
      #
      # In this case regeneration is added as a half-assed security measure, as if apiserver is removed, we don't
      # want for it to be able to pretend like it is a valid server.
      #
      # However, certificate revokation is complicated in my setup, and I can't show it here.
      regenerateOnOwnerAdded = true;
      expectedOwners = ["controlplane-1" "controlplane-2"];
      generator = {mkKubernetesCert}:
        mkKubernetesCert {
          inherit sans;
          subj.CN = "kubernetes";
          impureOn = "[CENSORED]";
        };
    };
}