feat: [torrust#177] new config option for log level

```toml
log_level = "info"
```

The level can be:

- `off`
- `error`
- `warn`
- `info`
- `debug`
- `trace`

config-idx-back.local.toml

@@ -1,3 +1,5 @@
+log_level = "info"
+
 [website]
 name = "Torrust"
 

config.local.toml

@@ -1,3 +1,5 @@
+log_level = "info"
+
 [website]
 name = "Torrust"
 

src/app.rs

@@ -30,7 +30,9 @@ pub struct Running {
 
 #[allow(clippy::too_many_lines)]
 pub async fn run(configuration: Configuration, api_implementation: &Implementation) -> Running {
-    logging::setup();
+    let log_level = configuration.settings.read().await.log_level.clone();
+
+    logging::setup(&log_level);
 
     let configuration = Arc::new(configuration);
 

src/bootstrap/logging.rs

@@ -13,10 +13,8 @@ use log::{info, LevelFilter};
 
 static INIT: Once = Once::new();
 
-pub fn setup() {
-    // todo: load log level from configuration.
-
-    let level = config_level_or_default(&None);
+pub fn setup(log_level: &Option<String>) {
+    let level = config_level_or_default(log_level);
 
     if level == log::LevelFilter::Off {
         return;

src/config.rs

@@ -257,6 +257,9 @@ impl Default for ImageCache {
 /// The whole configuration for the backend.
 #[derive(Debug, Default, Clone, Serialize, Deserialize)]
 pub struct TorrustBackend {
+    /// Logging level. Possible values are: `Off`, `Error`, `Warn`, `Info`,
+    /// `Debug` and `Trace`. Default is `Info`.
+    pub log_level: Option<String>,
     /// The website customizable values.
     pub website: Website,
     /// The tracker configuration.

src/console/commands/import_tracker_statistics.rs

@@ -85,7 +85,9 @@ pub async fn import() {
 
     let configuration = init_configuration().await;
 
-    logging::setup();
+    let log_level = configuration.settings.read().await.log_level.clone();
+
+    logging::setup(&log_level);
 
     let cfg = Arc::new(configuration);