ntfy crowdsec

modules/nixos/services/crowdsec/default.nix

@@ -13,34 +13,20 @@ let
   ntfyServer = "https://ntfy.mjallen.dev";
   ntfyTopic = "crowdsec";
 
-  # CrowdSec HTTP notification plugin config — written to
-  # /etc/crowdsec/notifications/ntfy.yaml at runtime.  Credentials are
-  # injected via EnvironmentFile so the plugin can reference them with
-  # {{env "NTFY_USER"}} / {{env "NTFY_PASSWORD"}} in the URL.
-  ntfyPluginConfig = pkgs.writeText "crowdsec-ntfy.yaml" ''
-    type: http
-    name: ntfy_plugin
-    log_level: info
-    format: |
-      {{range . -}}
-      CrowdSec blocked: {{.Scenario}}
-      Source IP:  {{.Source.Value}}
-      Country:    {{.Source.Cn}}
-      Decisions:  {{.Decisions | len}}
-      {{range .Decisions -}}
-      Action: {{.Type}} for {{.Duration}}
-      {{end}}
-      {{- end}}
-    url: ${ntfyServer}/${ntfyTopic}
-    method: POST
-    headers:
-      Title: "CrowdSec: {{(index . 0).Scenario}}"
-      Priority: "high"
-      Tags: "rotating_light,shield"
-      Authorization: "Basic {{b64enc (print (env "NTFY_USER") ":" (env "NTFY_PASSWORD"))}}"
-    skip_tls_verify: false
-    timeout: 10s
-  '';
+  # Build the notification-http plugin binary from the crowdsec source.
+  # The nixpkgs crowdsec package omits all notification plugin binaries;
+  # we build just the http one we need.
+  crowdsecHttpPlugin = pkgs.buildGoModule {
+    pname = "crowdsec-notification-http";
+    inherit (pkgs.crowdsec) version src;
+    vendorHash = pkgs.crowdsec.vendorHash or null;
+    subPackages = [ "cmd/notification-http" ];
+    ldflags = [
+      "-s"
+      "-w"
+    ];
+    meta.description = "CrowdSec HTTP notification plugin";
+  };
 
   crowdsecConfig = lib.${namespace}.mkModule {
     inherit config name;
@@ -144,17 +130,26 @@ let
             ];
           };
           settings = {
-            general.api = {
-              server = {
-                enable = true;
-                listen_uri = "${cfg.listenAddress}:${toString cfg.port}";
+            general = {
+              api = {
+                server = {
+                  enable = true;
+                  listen_uri = "${cfg.listenAddress}:${toString cfg.port}";
+                };
+                client = {
+                  credentials_path = lib.mkForce "${cfg.configDir}/crowdsec/client.yaml";
+                };
               };
-              client = {
-                credentials_path = lib.mkForce "${cfg.configDir}/crowdsec/client.yaml";
+              # plugin_config must be in settings.general so it ends up in the
+              # NixOS-generated crowdsec.yaml that the daemon reads via -c.
+              plugin_config = lib.mkIf cfg.ntfy.enable {
+                user = "crowdsec";
+                group = "crowdsec";
               };
             };
             capi.credentialsFile = lib.mkDefault "${cfg.configDir}/crowdsec/capi.yaml";
           };
+
         };
 
         crowdsec-firewall-bouncer = {
@@ -175,7 +170,12 @@ let
       # but /var/lib/crowdsec already exists as a real dir. Disabling DynamicUser on
       # those two services lets them use the real crowdsec user/group instead, which is
       # consistent with how crowdsec.service itself runs.
-      systemd.services.crowdsec.serviceConfig.DynamicUser = lib.mkForce false;
+      systemd.services.crowdsec.serviceConfig = lib.mkMerge [
+        { DynamicUser = lib.mkForce false; }
+        (lib.mkIf (cfg.ntfy.enable && cfg.ntfy.envFile != "") {
+          EnvironmentFile = [ cfg.ntfy.envFile ];
+        })
+      ];
       systemd.services.crowdsec-firewall-bouncer.serviceConfig.DynamicUser = lib.mkForce false;
       systemd.services.crowdsec-firewall-bouncer-register.serviceConfig.DynamicUser = lib.mkForce false;
 
@@ -220,12 +220,11 @@ let
 
       # crowdsec-firewall-bouncer-register calls cscli without -c, so cscli
       # looks for /etc/crowdsec/config.yaml. The upstream crowdsec.service uses
-      # a nix store path via -c and never creates that file. Expose the config
-      # at /etc/crowdsec/config.yaml by extracting the store path from the
-      # crowdsec service's ExecStart list at NixOS eval time.
+      # a nix store path via -c and never creates that file. Expose the full
+      # NixOS-generated config (which includes plugin_config via
+      # settings.general.plugin_config) at the well-known path.
       environment.etc."crowdsec/config.yaml" =
         let
-          # ExecStart is [ " " "<store>/crowdsec -c <config-file> -info" ]
           execStart = builtins.elemAt config.systemd.services.crowdsec.serviceConfig.ExecStart 1;
           configPath = builtins.head (builtins.match ".* -c ([^ ]+) .*" execStart);
         in
@@ -240,16 +239,27 @@ let
       # ntfy notifications via the CrowdSec HTTP notification plugin
       # ---------------------------------------------------------------------------
 
-      # Drop the plugin config YAML into /etc/crowdsec/notifications/.
-      # CrowdSec scans this directory on startup and registers any plugin
-      # config files it finds.
-      environment.etc."crowdsec/notifications/ntfy.yaml" = lib.mkIf cfg.ntfy.enable {
-        source = ntfyPluginConfig;
-        mode = "0440";
+      # Place the notification-http binary at the path the NixOS crowdsec module
+      # hardcodes for plugin_dir (/etc/crowdsec/plugins/).  CrowdSec matches
+      # plugins by their filename — it expects "notification-http" for type=http.
+      environment.etc."crowdsec/plugins/notification-http" = lib.mkIf cfg.ntfy.enable {
+        source = "${crowdsecHttpPlugin}/bin/notification-http";
+        mode = "0550";
         user = "crowdsec";
         group = "crowdsec";
       };
 
+      # The ntfy plugin config YAML (with credentials baked in) is managed as a
+      # SOPS template in sops.nix — it renders to /run/secrets/rendered/crowdsec/
+      # notifications/ntfy.yaml at runtime.  We use a tmpfiles symlink to expose
+      # it at the path CrowdSec scans, since environment.etc can't reference
+      # /run paths as source.
+      systemd.tmpfiles.rules = lib.mkIf cfg.ntfy.enable [
+        "L /etc/crowdsec/notifications/ntfy.yaml - - - - ${
+          config.sops.templates."crowdsec/notifications/ntfy.yaml".path
+        }"
+      ];
+
       # CrowdSec profiles.yaml: route every alert to the ntfy plugin.
       # This replaces the default "do nothing" profile.
       environment.etc."crowdsec/profiles.yaml" = lib.mkIf cfg.ntfy.enable {
@@ -279,13 +289,6 @@ let
         group = "crowdsec";
       };
 
-      # Inject NTFY_USER and NTFY_PASSWORD into the crowdsec service so the
-      # HTTP plugin template can reference them.  The plugin config uses
-      # {{env "NTFY_BASIC_AUTH"}} — a pre-encoded "user:pass" base64 string
-      # for the Authorization: Basic header — computed in ExecStartPre.
-      systemd.services.crowdsec.serviceConfig.EnvironmentFile = lib.mkIf cfg.ntfy.enable [
-        cfg.ntfy.envFile
-      ];
     };
   };
 in

systems/x86_64-linux/jallen-nas/sops.nix

@@ -259,10 +259,10 @@ in
       "jallen-nas/ntfy/auth-users" = {
         sopsFile = defaultSops;
       };
+
       "jallen-nas/ntfy/user" = {
         sopsFile = defaultSops;
         mode = "0440";
-        owner = "grafana";
         group = "keys";
         restartUnits = [
           "grafana.service"
@@ -273,7 +273,6 @@ in
       "jallen-nas/ntfy/password" = {
         sopsFile = defaultSops;
         mode = "0440";
-        owner = "grafana";
         group = "keys";
         restartUnits = [
           "grafana.service"
@@ -357,7 +356,8 @@ in
           NTFY_USER=${config.sops.placeholder."jallen-nas/ntfy/user"}
           NTFY_PASSWORD=${config.sops.placeholder."jallen-nas/ntfy/password"}
         '';
-        mode = "0600";
+        mode = "0640";
+        group = "keys";
         restartUnits = [
           "crowdsec.service"
           "upsmon.service"
@@ -366,6 +366,33 @@ in
         ];
       };
 
+      # CrowdSec HTTP notification plugin config with credentials baked in.
+      # The plugin process spawned by crowdsec/cscli reads this file directly.
+      # Credentials are embedded in the URL using HTTP basic auth so no
+      # base64 encoding or env var injection is needed.
+      "crowdsec/notifications/ntfy.yaml" = {
+        content = ''
+          type: http
+          name: ntfy_plugin
+          log_level: info
+          format: "{{range . -}}CrowdSec blocked: {{.Scenario}}\nSource IP: {{.Source.Value}}\nCountry: {{.Source.Cn}}\nDecisions: {{.Decisions | len}}{{range .Decisions}}\nAction: {{.Type}} for {{.Duration}}{{end}}\n{{end}}"
+          url: https://${config.sops.placeholder."jallen-nas/ntfy/user"}:${
+            config.sops.placeholder."jallen-nas/ntfy/password"
+          }@ntfy.mjallen.dev/crowdsec
+          method: POST
+          headers:
+            Title: "CrowdSec: {{(index . 0).Scenario}}"
+            Priority: "high"
+            Tags: "rotating_light,shield"
+          skip_tls_verify: false
+          timeout: 10s
+        '';
+        mode = "0440";
+        owner = "crowdsec";
+        group = "crowdsec";
+        restartUnits = [ "crowdsec.service" ];
+      };
+
       "paperless.env" = {
         content = ''
           PAPERLESS_ADMIN_USER = "mjallen"

systems/x86_64-linux/jallen-nas/users.nix

@@ -57,8 +57,16 @@ in
       prometheus = {
         extraGroups = [ "keys" ];
       };
+
+      # crowdsec needs to read the ntfy.env SOPS template for notifications.
+      crowdsec = {
+        isSystemUser = true;
+        group = "crowdsec";
+        extraGroups = [ "keys" ];
+      };
     };
 
     groups.nextcloud-exporter = { };
+    groups.crowdsec = { };
   };
 }