fixes and features

src/config.rs

@@ -10,6 +10,8 @@ pub struct Config {
     pub files_dir: String,
     pub upload_max_size_bytes: usize,
     pub asset_version: String,
+    pub asset_cache_max_age_seconds: u64,
+    pub file_cache_max_age_seconds: u64,
     pub smtp: Option<crate::state::SmtpConfig>,
     pub registration_enabled: bool,
     pub account_confirmation_required: bool,
@@ -60,6 +62,8 @@ impl Config {
                 .checked_mul(1024 * 1024)
                 .ok_or("UPLOAD_MAX_SIZE_MB is too large")?,
             asset_version: env!("CARGO_PKG_VERSION").to_owned(),
+            asset_cache_max_age_seconds: env_nonnegative_u64("ASSET_CACHE_MAX_AGE_SECONDS", 600)?,
+            file_cache_max_age_seconds: env_nonnegative_u64("FILE_CACHE_MAX_AGE_SECONDS", 600)?,
             smtp,
             registration_enabled: env_bool("REGISTRATION_ENABLED", false)?,
             account_confirmation_required: env_bool("ACCOUNT_CONFIRMATION_REQUIRED", false)?,
@@ -100,3 +104,7 @@ fn env_positive_i64(name: &str, default: i64) -> Result<i64, Box<dyn std::error:
     }
     Ok(value)
 }
+
+fn env_nonnegative_u64(name: &str, default: u64) -> Result<u64, Box<dyn std::error::Error>> {
+    Ok(env_var(name, &default.to_string()).parse()?)
+}