proper config file

src/config.rs

@@ -0,0 +1,59 @@
+use demostf_client::ApiClient;
+use serde::Deserialize;
+use std::fs::read_to_string;
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub enum ConfigError {
+    #[error("Failed to read config from {path}: {error}")]
+    Read { error: std::io::Error, path: String },
+    #[error("Failed to parse config from {path}: {error}")]
+    Parse {
+        error: toml::de::Error,
+        path: String,
+    },
+}
+
+#[derive(Debug, Deserialize)]
+pub struct Config {
+    pub api: ApiConfig,
+    pub storage: StorageConfig,
+    pub cleanup: CleanupConfig,
+}
+
+impl Config {
+    pub fn load(path: String) -> Result<Self, ConfigError> {
+        let content = read_to_string(&path).map_err(|error| ConfigError::Read {
+            error,
+            path: path.clone(),
+        })?;
+        toml::from_str(&content).map_err(|error| ConfigError::Parse { error, path })
+    }
+}
+
+#[derive(Debug, Deserialize)]
+pub struct ApiConfig {
+    #[serde(default = "default_api_base")]
+    pub url: String,
+    pub key_file: String,
+}
+
+fn default_api_base() -> String {
+    ApiClient::DEMOS_TF_BASE_URL.into()
+}
+
+#[derive(Debug, Deserialize)]
+pub struct CleanupConfig {
+    #[serde(default = "default_from_backend")]
+    pub from_backend: String,
+    pub age: u64,
+}
+
+fn default_from_backend() -> String {
+    "freezer".into()
+}
+
+#[derive(Debug, Deserialize)]
+pub struct StorageConfig {
+    pub root: String,
+}