add stock hledger updater

configs/workhorse/configuration.nix

@@ -29,6 +29,7 @@
     ./jupyter.nix
     ./mysql.nix
     ./property.nix
+    ./finance.nix
   ];
 
   nixpkgs.config.permittedInsecurePackages =

configs/workhorse/finance.nix

@@ -0,0 +1,62 @@
+{ lib, config, pkgs, ... }:
+let
+
+  # find symbols with
+  # https://www.alphavantage.co/query?function=SYMBOL_SEARCH&keywords=<keywords>&apikey=<api_key>
+  # as described here : https://www.alphavantage.co/documentation/#symbolsearch
+  #
+  # example:
+  # --------
+  # stocks = [
+  #   {
+  #     friendly_name = "google";
+  #     symbol = "GOOGL.DEX";
+  #     name = "google";
+  #     currency = "$";
+  #   }
+  # ];
+  # results in
+  # P 2020-01-30 GOOGL $123
+  stocks = import <secrets/finance/stocks>;
+  stocksFile = toString /home/syncthing/finance/hledger/stocks.journal;
+
+in {
+
+  systemd.services = let
+    pullService = { name, symbol, currency, friendly_name, ... }: {
+      name = "pull_stock_${friendly_name}";
+      value = {
+        enable = true;
+        description = "pull stock_${friendly_name} for hledger";
+        serviceConfig = {
+          User = "syncthing";
+          Type = "oneshot";
+        };
+        script = ''
+          SYMBOL="${symbol}"
+          APIKEY=${lib.fileContents <secrets/finance/alphavantage/apikey>}
+          ${pkgs.curl}/bin/curl --location --silent \
+            "https://www.alphavantage.co/query?function=GLOBAL_QUOTE&symbol=$SYMBOL&apikey=$APIKEY" \
+            | ${pkgs.jq}/bin/jq --raw-output '.["Global Quote"]
+            | "P \(.["07. latest trading day"]) ${name} ${currency}\(.["05. price"] | tonumber)"' \
+          >> ${stocksFile}
+        '';
+      };
+    };
+  in builtins.listToAttrs (map pullService stocks);
+
+  systemd.timers = let
+    pullTimer = { friendly_name, ... }: {
+      name = "pull_stock_${friendly_name}";
+      value = {
+        enable = true;
+        wantedBy = [ "multi-user.target" ];
+        timerConfig = {
+          OnCalendar = "weekly";
+          Persistent = "true";
+        };
+      };
+    };
+  in builtins.listToAttrs (map pullTimer stocks);
+
+}