diff options
Diffstat (limited to 'nixos/modules/services/monitoring/certspotter.nix')
-rw-r--r-- | nixos/modules/services/monitoring/certspotter.nix | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/nixos/modules/services/monitoring/certspotter.nix b/nixos/modules/services/monitoring/certspotter.nix new file mode 100644 index 000000000000..aafa29daa872 --- /dev/null +++ b/nixos/modules/services/monitoring/certspotter.nix @@ -0,0 +1,143 @@ +{ config +, lib +, pkgs +, ... }: + +let + cfg = config.services.certspotter; + + configDir = pkgs.linkFarm "certspotter-config" ( + lib.toList { + name = "watchlist"; + path = pkgs.writeText "certspotter-watchlist" (builtins.concatStringsSep "\n" cfg.watchlist); + } + ++ lib.optional (cfg.emailRecipients != [ ]) { + name = "email_recipients"; + path = pkgs.writeText "certspotter-email_recipients" (builtins.concatStringsSep "\n" cfg.emailRecipients); + } + # always generate hooks dir when no emails are provided to allow running cert spotter with no hooks/emails + ++ lib.optional (cfg.emailRecipients == [ ] || cfg.hooks != [ ]) { + name = "hooks.d"; + path = pkgs.linkFarm "certspotter-hooks" (lib.imap1 (i: path: { + inherit path; + name = "hook${toString i}"; + }) cfg.hooks); + }); +in +{ + options.services.certspotter = { + enable = lib.mkEnableOption "Cert Spotter, a Certificate Transparency log monitor"; + + package = lib.mkPackageOptionMD pkgs "certspotter" { }; + + startAtEnd = lib.mkOption { + type = lib.types.bool; + description = '' + Whether to skip certificates issued before the first launch of Cert Spotter. + Setting this to `false` will cause Cert Spotter to download tens of terabytes of data. + ''; + default = true; + }; + + sendmailPath = lib.mkOption { + type = with lib.types; nullOr path; + description = '' + Path to the `sendmail` binary. By default, the local sendmail wrapper is used + (see {option}`services.mail.sendmailSetuidWrapper`}). + ''; + example = lib.literalExpression ''"''${pkgs.system-sendmail}/bin/sendmail"''; + }; + + watchlist = lib.mkOption { + type = with lib.types; listOf str; + description = "Domain names to watch. To monitor a domain with all subdomains, prefix its name with `.` (e.g. `.example.org`)."; + default = [ ]; + example = [ ".example.org" "another.example.com" ]; + }; + + emailRecipients = lib.mkOption { + type = with lib.types; listOf str; + description = "A list of email addresses to send certificate updates to."; + default = [ ]; + }; + + hooks = lib.mkOption { + type = with lib.types; listOf path; + description = '' + Scripts to run upon the detection of a new certificate. See `man 8 certspotter-script` or + [the GitHub page](https://github.com/SSLMate/certspotter/blob/${pkgs.certspotter.src.rev or "master"}/man/certspotter-script.md) + for more info. + ''; + default = [ ]; + example = lib.literalExpression '' + [ + (pkgs.writeShellScript "certspotter-hook" ''' + echo "Event summary: $SUMMARY." + ''') + ] + ''; + }; + + extraFlags = lib.mkOption { + type = with lib.types; listOf str; + description = "Extra command-line arguments to pass to Cert Spotter"; + example = [ "-no_save" ]; + default = [ ]; + }; + }; + + config = lib.mkIf cfg.enable { + assertions = [ + { + assertion = (cfg.emailRecipients != [ ]) -> (cfg.sendmailPath != null); + message = '' + You must configure the sendmail setuid wrapper (services.mail.sendmailSetuidWrapper) + or services.certspotter.sendmailPath + ''; + } + ]; + + services.certspotter.sendmailPath = let + inherit (config.security) wrapperDir; + inherit (config.services.mail) sendmailSetuidWrapper; + in lib.mkMerge [ + (lib.mkIf (sendmailSetuidWrapper != null) (lib.mkOptionDefault "${wrapperDir}/${sendmailSetuidWrapper.program}")) + (lib.mkIf (sendmailSetuidWrapper == null) (lib.mkOptionDefault null)) + ]; + + users.users.certspotter = { + description = "Cert Spotter user"; + group = "certspotter"; + home = "/var/lib/certspotter"; + isSystemUser = true; + }; + users.groups.certspotter = { }; + + systemd.services.certspotter = { + description = "Cert Spotter - Certificate Transparency Monitor"; + after = [ "network.target" ]; + wantedBy = [ "multi-user.target" ]; + environment.CERTSPOTTER_CONFIG_DIR = configDir; + environment.SENDMAIL_PATH = if cfg.sendmailPath != null then cfg.sendmailPath else "/run/current-system/sw/bin/false"; + script = '' + export CERTSPOTTER_STATE_DIR="$STATE_DIRECTORY" + cd "$CERTSPOTTER_STATE_DIR" + ${lib.optionalString cfg.startAtEnd '' + if [[ ! -d logs ]]; then + # Don't download certificates issued before the first launch + exec ${cfg.package}/bin/certspotter -start_at_end ${lib.escapeShellArgs cfg.extraFlags} + fi + ''} + exec ${cfg.package}/bin/certspotter ${lib.escapeShellArgs cfg.extraFlags} + ''; + serviceConfig = { + User = "certspotter"; + Group = "certspotter"; + StateDirectory = "certspotter"; + }; + }; + }; + + meta.maintainers = with lib.maintainers; [ chayleaf ]; + meta.doc = ./certspotter.md; +} |