Add log4rs config and fix main to use exit codes

log4rs_config.yaml

@@ -0,0 +1,59 @@
+refresh_rate: 30 seconds
+
+appenders:
+
+  stdout:
+    kind: console
+    encoder:
+      pattern: "{d(%Y-%m-%d %H:%M:%S)} | {({l}):5.5} | {f}:{L} — {m}{n}"
+
+  rolling_logs:
+    kind: rolling_file
+    path: logs/yorokobot-latest.log
+    encoder:
+      pattern: "{d(%Y-%m-%d %H:%M:%S)} | {({l}):5.5} | {f}:{L} — {m}{n}"
+    policy:
+      trigger: # Specify when to switch to another log file 
+        kind: size
+        limit: 30 mb
+
+      roller: # Specify what to do with older logs files
+        kind: fixed_window
+        pattern: logs/yorokobot_{}.gz
+        count: 10
+
+  rolling_debug:
+    kind: rolling_file
+    path: logs/traces-latest.log
+    encoder:
+      pattern: "{d(%Y-%m-%d %H:%M:%S)} | {({l}):5.5} | {f}:{L} — {m}{n}"
+    policy:
+      trigger:
+        kind: size
+        limit: 30 mb
+        
+      roller:
+        kind: fixed_window
+        pattern: logs/yorokobot_traces_{}.gz
+        count: 20
+
+root:
+  level: warn
+  appenders:
+    - stdout
+
+loggers:
+  bot_infos:
+    level: info
+    appenders:
+      - rolling_debug
+
+  bot_warn_errors:
+    level: warn 
+    appenders:
+      - rolling_logs
+  
+  bot_traces:
+    level: debug
+    appenders:
+      - rolling_debug

src/main.rs

@@ -1,3 +1,4 @@
+use log::error;
 use std::env;
 
 use yorokobot::{
@@ -6,22 +7,51 @@ use yorokobot::{
 };
 
 #[tokio::main]
-async fn main() {
+async fn main() -> std::process::ExitCode {
-    let discord_token = env::var("DISCORD_TOKEN").expect("Cannot fetch Discord token");
+    // Start the logger
+    log4rs::init_file("log4rs_config.yaml", Default::default()).unwrap();
 
-    let mongodb_uri = env::var("MONGODB_URI").expect("Cannot fetch Mongo URI");
+    let discord_token = match env::var("DISCORD_TOKEN") {
+        Ok(t) => t,
+        Err(_) => {
+            error!(target: "bot_warn_errors", "Could not find DISCORD_TOKEN environment variable.");
+            return std::process::ExitCode::FAILURE;
+        }
+    };
+
+    let mongodb_uri = match env::var("MONGODB_URI") {
+        Ok(u) => u,
+        Err(_) => {
+            error!(target: "bot_warn_errors", "Could not find MONGODB_URI environment variable.");
+            return std::process::ExitCode::FAILURE;
+        }
+    };
 
     let credentials = ClientCredentials {
         discord_token: &discord_token,
         mongo_uri: &mongodb_uri,
     };
 
-    let mut client = Client::new(credentials)
+    let mut client = match Client::new(credentials).await {
-        .await
+        Ok(c) => c,
-        .expect("Could not create client");
+        Err(_) => {
+            error!(target: "bot_warn_errors", "Could not instantiate the bot client.");
+            return std::process::ExitCode::FAILURE;
+        }
+    };
 
-    client.connect().await.unwrap_or_else(|error| match error {
+    if let Err(error) = client.connect().await {
-        ClientsError::Database(e) => panic!("Could not connect to database: {:?}", e),
+        match error {
-        ClientsError::Discord(e) => panic!("Could not connect to Discord: {:?}", e),
+            ClientsError::Database(e) => {
-    });
+                error!(target: "bot_warn_errors", "Could not connect to database: {:?}", e)
+            }
+            ClientsError::Discord(e) => {
+                error!(target: "bot_warn_errors", "Could not connect to Discord: {:?}", e)
+            }
+        };
+
+        return std::process::ExitCode::FAILURE;
+    }
+
+    std::process::ExitCode::SUCCESS
 }