diff options
Diffstat (limited to 'nixos/modules/security/acme/default.nix')
| -rw-r--r-- | nixos/modules/security/acme/default.nix | 149 |
1 files changed, 132 insertions, 17 deletions
diff --git a/nixos/modules/security/acme/default.nix b/nixos/modules/security/acme/default.nix index 8aee71c864d0a..92bed172f4522 100644 --- a/nixos/modules/security/acme/default.nix +++ b/nixos/modules/security/acme/default.nix @@ -1,6 +1,8 @@ { config, lib, pkgs, options, ... }: with lib; let + + cfg = config.security.acme; opt = options.security.acme; user = if cfg.useRoot then "root" else "acme"; @@ -14,6 +16,36 @@ let mkAccountHash = acmeServer: data: mkHash "${toString acmeServer} ${data.keyType} ${data.email}"; accountDirRoot = "/var/lib/acme/.lego/accounts/"; + lockdir = "/run/acme/"; + concurrencyLockfiles = map (n: "${toString n}.lock") (lib.range 1 cfg.maxConcurrentRenewals); + # Assign elements of `baseList` to each element of `needAssignmentList`, until the latter is exhausted. + # returns: [{fst = "element of baseList"; snd = "element of needAssignmentList"}] + roundRobinAssign = baseList: needAssignmentList: + if baseList == [] then [] + else _rrCycler baseList baseList needAssignmentList; + _rrCycler = with builtins; origBaseList: workingBaseList: needAssignmentList: + if (workingBaseList == [] || needAssignmentList == []) + then [] + else + [{ fst = head workingBaseList; snd = head needAssignmentList;}] ++ + _rrCycler origBaseList (if (tail workingBaseList == []) then origBaseList else tail workingBaseList) (tail needAssignmentList); + attrsToList = mapAttrsToList (attrname: attrval: {name = attrname; value = attrval;}); + # for an AttrSet `funcsAttrs` having functions as values, apply single arguments from + # `argsList` to them in a round-robin manner. + # Returns an attribute set with the applied functions as values. + roundRobinApplyAttrs = funcsAttrs: argsList: lib.listToAttrs (map (x: {inherit (x.snd) name; value = x.snd.value x.fst;}) (roundRobinAssign argsList (attrsToList funcsAttrs))); + wrapInFlock = lockfilePath: script: + # explainer: https://stackoverflow.com/a/60896531 + '' + exec {LOCKFD}> ${lockfilePath} + echo "Waiting to acquire lock ${lockfilePath}" + ${pkgs.flock}/bin/flock ''${LOCKFD} || exit 1 + echo "Acquired lock ${lockfilePath}" + '' + + script + "\n" + + ''echo "Releasing lock ${lockfilePath}" # only released after process exit''; + + # There are many services required to make cert renewals work. # They all follow a common structure: # - They inherit this commonServiceConfig @@ -31,6 +63,7 @@ let ProtectSystem = "strict"; ReadWritePaths = [ "/var/lib/acme" + lockdir ]; PrivateTmp = true; @@ -118,7 +151,8 @@ let # We don't want this to run every time a renewal happens RemainAfterExit = true; - # These StateDirectory entries negate the need for tmpfiles + # StateDirectory entries are a cleaner, service-level mechanism + # for dealing with persistent service data StateDirectory = [ "acme" "acme/.lego" "acme/.lego/accounts" ]; StateDirectoryMode = 755; WorkingDirectory = "/var/lib/acme"; @@ -127,6 +161,25 @@ let ExecStart = "+" + (pkgs.writeShellScript "acme-fixperms" script); }; }; + lockfilePrepareService = { + description = "Manage lock files for acme services"; + + # ensure all required lock files exist, but none more + script = '' + GLOBIGNORE="${concatStringsSep ":" concurrencyLockfiles}" + rm -f * + unset GLOBIGNORE + + xargs touch <<< "${toString concurrencyLockfiles}" + ''; + + serviceConfig = commonServiceConfig // { + # We don't want this to run every time a renewal happens + RemainAfterExit = true; + WorkingDirectory = lockdir; + }; + }; + certToConfig = cert: data: let acmeServer = data.server; @@ -229,10 +282,10 @@ let }; }; - selfsignService = { + selfsignService = lockfileName: { description = "Generate self-signed certificate for ${cert}"; - after = [ "acme-selfsigned-ca.service" "acme-fixperms.service" ]; - requires = [ "acme-selfsigned-ca.service" "acme-fixperms.service" ]; + after = [ "acme-selfsigned-ca.service" "acme-fixperms.service" ] ++ optional (cfg.maxConcurrentRenewals > 0) "acme-lockfiles.service"; + requires = [ "acme-selfsigned-ca.service" "acme-fixperms.service" ] ++ optional (cfg.maxConcurrentRenewals > 0) "acme-lockfiles.service"; path = with pkgs; [ minica ]; @@ -256,7 +309,7 @@ let # Working directory will be /tmp # minica will output to a folder sharing the name of the first domain # in the list, which will be ${data.domain} - script = '' + script = (if (lockfileName == null) then lib.id else wrapInFlock "${lockdir}${lockfileName}") '' minica \ --ca-key ca/key.pem \ --ca-cert ca/cert.pem \ @@ -277,10 +330,10 @@ let ''; }; - renewService = { + renewService = lockfileName: { description = "Renew ACME certificate for ${cert}"; - after = [ "network.target" "network-online.target" "acme-fixperms.service" "nss-lookup.target" ] ++ selfsignedDeps; - wants = [ "network-online.target" "acme-fixperms.service" ] ++ selfsignedDeps; + after = [ "network.target" "network-online.target" "acme-fixperms.service" "nss-lookup.target" ] ++ selfsignedDeps ++ optional (cfg.maxConcurrentRenewals > 0) "acme-lockfiles.service"; + wants = [ "network-online.target" "acme-fixperms.service" ] ++ selfsignedDeps ++ optional (cfg.maxConcurrentRenewals > 0) "acme-lockfiles.service"; # https://github.com/NixOS/nixpkgs/pull/81371#issuecomment-605526099 wantedBy = optionals (!config.boot.isContainer) [ "multi-user.target" ]; @@ -309,8 +362,14 @@ let "/var/lib/acme/.lego/${cert}/${certDir}:/tmp/certificates" ]; - # Only try loading the credentialsFile if the dns challenge is enabled - EnvironmentFile = mkIf useDns data.credentialsFile; + # Only try loading the environmentFile if the dns challenge is enabled + EnvironmentFile = mkIf useDns data.environmentFile; + + Environment = mkIf useDns + (mapAttrsToList (k: v: ''"${k}=%d/${k}"'') data.credentialFiles); + + LoadCredential = mkIf useDns + (mapAttrsToList (k: v: "${k}:${v}") data.credentialFiles); # Run as root (Prefixed with +) ExecStartPost = "+" + (pkgs.writeShellScript "acme-postrun" '' @@ -329,7 +388,7 @@ let }; # Working directory will be /tmp - script = '' + script = (if (lockfileName == null) then lib.id else wrapInFlock "${lockdir}${lockfileName}") '' ${optionalString data.enableDebugLogs "set -x"} set -euo pipefail @@ -443,6 +502,10 @@ let defaultText = if isDefaults then default else literalExpression "config.security.acme.defaults.${name}"; }; in { + imports = [ + (mkRenamedOptionModule [ "credentialsFile" ] [ "environmentFile" ]) + ]; + options = { validMinDays = mkOption { type = types.int; @@ -554,9 +617,9 @@ let ''; }; - credentialsFile = mkOption { + environmentFile = mkOption { type = types.nullOr types.path; - inherit (defaultAndText "credentialsFile" null) default defaultText; + inherit (defaultAndText "environmentFile" null) default defaultText; description = lib.mdDoc '' Path to an EnvironmentFile for the cert's service containing any required and optional environment variables for your selected dnsProvider. @@ -566,6 +629,24 @@ let example = "/var/src/secrets/example.org-route53-api-token"; }; + credentialFiles = mkOption { + type = types.attrsOf (types.path); + inherit (defaultAndText "credentialFiles" {}) default defaultText; + description = lib.mdDoc '' + Environment variables suffixed by "_FILE" to set for the cert's service + for your selected dnsProvider. + To find out what values you need to set, consult the documentation at + <https://go-acme.github.io/lego/dns/> for the corresponding dnsProvider. + This allows to securely pass credential files to lego by leveraging systemd + credentials. + ''; + example = literalExpression '' + { + "RFC2136_TSIG_SECRET_FILE" = "/run/secrets/tsig-secret-example.org"; + } + ''; + }; + dnsPropagationCheck = mkOption { type = types.bool; inherit (defaultAndText "dnsPropagationCheck" true) default defaultText; @@ -755,6 +836,17 @@ in { } ''; }; + maxConcurrentRenewals = mkOption { + default = 5; + type = types.int; + description = lib.mdDoc '' + Maximum number of concurrent certificate generation or renewal jobs. All other + jobs will queue and wait running jobs to finish. Reduces the system load of + certificate generation. + + Set to `0` to allow unlimited number of concurrent job runs." + ''; + }; }; }; @@ -865,6 +957,13 @@ in { `security.acme.certs.${cert}.listenHTTP` must be provided. ''; } + { + assertion = all (hasSuffix "_FILE") (attrNames data.credentialFiles); + message = '' + Option `security.acme.certs.${cert}.credentialFiles` can only be + used for variables suffixed by "_FILE". + ''; + } ]) cfg.certs)); users.users.acme = { @@ -875,12 +974,28 @@ in { users.groups.acme = {}; - systemd.services = { - "acme-fixperms" = userMigrationService; - } // (mapAttrs' (cert: conf: nameValuePair "acme-${cert}" conf.renewService) certConfigs) + # for lock files, still use tmpfiles as they should better reside in /run + systemd.tmpfiles.rules = [ + "d ${lockdir} 0700 ${user} - - -" + "Z ${lockdir} 0700 ${user} - - -" + ]; + + systemd.services = let + renewServiceFunctions = mapAttrs' (cert: conf: nameValuePair "acme-${cert}" conf.renewService) certConfigs; + renewServices = if cfg.maxConcurrentRenewals > 0 + then roundRobinApplyAttrs renewServiceFunctions concurrencyLockfiles + else mapAttrs (_: f: f null) renewServiceFunctions; + selfsignServiceFunctions = mapAttrs' (cert: conf: nameValuePair "acme-selfsigned-${cert}" conf.selfsignService) certConfigs; + selfsignServices = if cfg.maxConcurrentRenewals > 0 + then roundRobinApplyAttrs selfsignServiceFunctions concurrencyLockfiles + else mapAttrs (_: f: f null) selfsignServiceFunctions; + in + { "acme-fixperms" = userMigrationService; } + // (optionalAttrs (cfg.maxConcurrentRenewals > 0) {"acme-lockfiles" = lockfilePrepareService; }) + // renewServices // (optionalAttrs (cfg.preliminarySelfsigned) ({ "acme-selfsigned-ca" = selfsignCAService; - } // (mapAttrs' (cert: conf: nameValuePair "acme-selfsigned-${cert}" conf.selfsignService) certConfigs))); + } // selfsignServices)); systemd.timers = mapAttrs' (cert: conf: nameValuePair "acme-${cert}" conf.renewTimer) certConfigs; |