Add log level configurable via environment variable

Available levels for now: debug, error. While the former is the
most verbose one and the latter the least verbose.

It sets it to 'debug' if in development mode.

configuration/config.go

@@ -14,6 +14,8 @@ const BODY_SIZE_LIMIT = 32 * 1024 * 1024    // 32 MB, in bytes
 type Config struct {
     Version     string `env:"VERSION"   envDefault:"N/A"`
 
+    LogLevel    string `env:"LOG_LEVE"  envDefault:"error"`
+
     Environment string `env:"ENV_NAME" envDefault:"development"`
     Host        string `env:"HOST" envDefault:"127.0.0.1"`
     Port        int16  `env:"PORT" envDefault:"3000"`
@@ -44,5 +46,19 @@ func New() ( *Config, error ){
         )
     }
 
+
+    if cfg.Environment == "development" { cfg.LogLevel = "debug" }
+
+    possibleLogLevels := map[ string ] bool {
+        "error":    true,
+        "debug":    true,
+    }
+    if _, ok := possibleLogLevels[ cfg.LogLevel ]; !ok {
+        return nil, errors.New(
+            fmt.Sprintf( "Invalid log level: %s", cfg.LogLevel ),
+        )
+    }
+
+
     return &cfg, nil
 }

routing/routes.go

@@ -25,6 +25,18 @@ func SetRoutes( router *f.App, config *configuration.Config, store state.Store,
         log.Fatal( err )
     }
 
+    if config.LogLevel == "debug" {
+        router.All( "*", func( c *f.Ctx ) error {
+            log.Printf( "%s  %s  mime:%s  agent:%s",
+                c.Path(),
+                c.Method(),
+                c.Get( f.HeaderContentType ),
+                c.Get( f.HeaderUserAgent ),
+            )
+            return c.Next()
+        })
+    }
+
 
     router.Get( "/", func( c *f.Ctx ) error {
         headers := c.GetReqHeaders()