fix package search path in wrapper

README.md

@@ -6,20 +6,23 @@ Fancy SaaS alerting services are great, but what if you want to know
 that the internet is down?
 
 This runs as a service on `localhost:8201` - once you've started it,
-create a "Webhook" type contact point in your Grafana instance
+create a "Webhook" type contact point in your Grafana instance,
 with the url `http://localhost:8201`.
 
-See Grafana [alerting contact points](https://grafana.com/docs/grafana/latest/alerting/contact-points/) documentation for background
+See Grafana [alerting contact points](https://grafana.com/docs/grafana/latest/alerting/contact-points/) documentation for background.
 
 
-## Installation (Nix)
+## Building and use (Nix)
 
-TBD
+### Try it quickly
 
-## Testing
+    $ nix-build build.nix
+	$ cp config.json.example config.json # and edit it
+	$ ./result/bin/grafana-sms-alert config.json
 
-Use the sample-alert.json in this repo to simulate the Grafana webhook
-invocation and check it's operational
+    $ curl -v --data @sample-alert.json http://localhost:8201
 
+### Install it meaningfully
 
-    curl -v --data @sample-alert.json http://localhost:8201
+The derivation in `default.nix` works with `callPackage`, so see
+`module-example.nix` for a sketch.

default.nix

@@ -21,7 +21,10 @@ in stdenv.mkDerivation {
      lua_path="`lua -e 'print(package.path)'`"
      lua_cpath="`lua -e 'print(package.cpath)'`"
 
-     makeWrapper ${myfennel}/bin/fennel $out/bin/grafana-sms-alert \
+     makeWrapper ${myfennel}/bin/fennel \
+      $out/bin/grafana-sms-alert \
+      --add-flags "--add-fennel-path $out/lib/?.fnl" \
+      --add-flags "--add-package-path $out/lib/?.lua" \
       --add-flags "$out/lib/main.fnl"
   '';
   buildInputs = [lua myfennel];

main.fnl

@@ -1,5 +1,4 @@
-(set _G.modem-spew io.stderr)
-
+; (set _G.modem-spew io.stderr)
 (local server (require :server))
 (local webhook (require :webhook))
 (local json (require :dkjson))
@@ -13,8 +12,6 @@
            (nil pos err) (error (.. "reading " filename ": "  err)))))
 
 (local { : view} (require :fennel))
-;(print (view m) (view err))
-
 
 (local sms ((. (require :sms) :new) { :smsc smsc :device device }))
 

module-example.nix

@@ -0,0 +1,22 @@
+{ config, lib, pkgs, ... }:
+let
+  grafana-sms-alert = pkgs.callPackage (fetchTarball "https://gti.telent.net/dan/grafana-sms-alert/archive/main.tar.gz") {};
+  smsConfig = builtins.toFile "config.json"
+    (builtins.toJSON {
+      smsc = "+447958879879";
+      number = "447000123456";
+      device = "/dev/serial/by-id/usb-HUAWEI_HUAWEI_HiLink-if00-port0";
+    });
+in {
+  config.systemd.services.grafana-sms = {
+    description = "SMS webhook for Grafana";
+    wantedBy = [ "multi-user.target" ];
+    serviceConfig = {
+      Restart = "always";
+      SyslogIdentifier = "grafana-sms";
+      ExecStart = ''
+        ${grafana-sms-alert}/bin/grafana-sms-alert ${smsConfig}
+      '';
+    };
+  };
+}