Add CLI arguments in addition to env vars.

deps.edn

@@ -19,6 +19,8 @@
 
         org.clojure/math.numeric-tower { :mvn/version "0.0.5" }
 
+        org.clojure/tools.cli { :mvn/version "1.0.206" }
+
         camel-snake-kebab/camel-snake-kebab { :mvn/version "0.4.2" }
         }
  :aliases {

module.nix

@@ -62,16 +62,13 @@ in {
         environment = {
           PRICEBOT_EXCHANGE_HOST = cfg.exchange-host;
           PRICEBOT_BEBOT_URL = cfg.mattermost-url;
-          PRICEBOT_BEBOT_AUTH_TOKEN_FILE = "%d/auth.token";
           PRICEBOT_BEBOT_CHANNEL_ID = opts.mattermost-channel-id;
           PRICEBOT_TARGET_CURRENCY = opts.currency;
           PRICEBOT_NOTIFY_USER = opts.notify-user;
         };
         serviceConfig = {
           ExecStart = pkgs.writeShellScript "launch-pricebot-${currency}.sh" ''
-            echo "CREDENTIALS_DIRECTORY $CREDENTIALS_DIRECTORY"
+            ${pricebot}/bin/pricebot --bebot-auth-token-file=$CREDENTIALS_DIRECTORY/auth.token
-            echo "CREDENTIALS_PATH $CREDENTIALS_PATH"
-            ${pricebot}/bin/pricebot
           '';
           DynamicUser = true;
           PrivateTmp = true;

src/pricebot/core.clj

@@ -9,7 +9,9 @@
             [fudo-clojure.result :as result :refer [map-success send-success dispatch-result success? unwrap]]
             [fudo-clojure.logging :as log]
             [clojure.string :as str]
-            [clojure.math.numeric-tower :refer [floor]])
+            [clojure.math.numeric-tower :refer [floor]]
+            [clojure.tools.cli :refer [parse-opts]]
+            [camel-snake-kebab.core :refer [->SCREAMING_SNAKE_CASE]])
   (:import java.math.RoundingMode
            java.time.format.DateTimeFormatter
            java.time.Duration
@@ -158,24 +160,50 @@
   (let [checks (create-checks logger)]
     (reify-bot hostname hostname currency checks)))
 
-(defn- getenv-or-fail [var]
+(def cli-opts
-  (if-let [val (System/getenv var)]
+  [["-x" "--exchange-host HOST" "Hostname of the Coinbase Pro target host."]
-    val
+   ["-b" "--bebot-url URL" "URL of the target Mattermost server."]
-    (throw (ex-info (str "Failed to read environment variable: " var) {}))))
+   ["-a" "--bebot-auth-token-file FILE" "Path to file containing the Bebot authentication token."]
+   ["-C" "--bebot-channel-id ID" "ID of channel in which to send price notifications."]
+   ["-c" "--currency CURRENCY" "Cryptocurrency to watch for price fluctuations."]
+   ["-u" "--notify-user USER" "User to notify of significant price fluctuations."]
+   ["-h" "--help"]])
+
+(defn get-key [opts k]
+  (if-let [opt (get opts k)]
+    [k opt]
+    [k (System/getenv (System/getenv (format "PRICEBOT_%s"
+                                             (-> k name ->SCREAMING_SNAKE_CASE))))]))
+
+(defn exit! [status msg]
+  (println msg)
+  (System/exit status))
+
+(defn get-args [keys args]
+  (let [input-opts (parse-opts args cli-opts)
+        opts       (into {} (map (partial get-key input-opts) keys))
+        missing    (filter (fn [k] (not (get opts k))) keys)]
+    (cond (:help opts)           (exit! 0 (println (:summary opts)))
+          (:errors opts)         (exit! 1 (println (str/join \newline (:errors opts))))
+          (not (empty? missing)) (exit! 2 (println (str "missing arguments: " (str/join " " (map name missing)))))
+          :else                  opts)))
 
 (defn -main [& args]
-  (let [exchange-hostname     (getenv-or-fail "PRICEBOT_EXCHANGE_HOST")
+  (let [required-keys [:exchange-host
-        bebot-host            (getenv-or-fail "PRICEBOT_BEBOT_URL")
+                       :currency
-        bebot-auth-token      (-> (getenv-or-fail "PRICEBOT_BEBOT_AUTH_TOKEN_FILE")
+                       :bebot-url
-                                  (slurp))
+                       :bebot-auth-token-file
-        bebot-channel-id      (getenv-or-fail "PRICEBOT_BEBOT_CHANNEL_ID")
+                       :bebot-channel-id
-        target-currency       (-> (getenv-or-fail "PRICEBOT_TARGET_CURRENCY")
+                       :notify-user]
-                                  (str/lower-case)
+        {:keys [exchange-host
-                                  (keyword))
+                currency
-        notify-user           (getenv-or-fail "PRICEBOT_NOTIFY_USER")]
+                bebot-url
-    (let [logger   (bebot-log/make-logger bebot-host bebot-auth-token bebot-channel-id notify-user)
+                bebot-auth-token-file
+                bebot-channel-id
+                notify-user]} (get-args required-keys args)]
+    (let [logger   (bebot-log/make-logger bebot-url (slurp bebot-auth-token-file) bebot-channel-id notify-user)
           checks   (create-checks logger)
-          bot      (reify-bot exchange-hostname target-currency)
+          bot      (reify-bot exchange-host (-> currency str/lower-case keyword))
           shutdown (chan)]
       (.addShutdownHook (Runtime/getRuntime)
                         (Thread. (fn []