Implement rpc_secret_file

src/garage/main.rs

@@ -173,7 +173,7 @@ async fn cli_command(opt: Opt) -> Result<(), Error> {
 	let net_key_hex_str = opt
 		.rpc_secret
 		.as_ref()
-		.or_else(|| config.as_ref().map(|c| &c.rpc_secret))
+		.or_else(|| config.as_ref().and_then(|c| c.rpc_secret.as_ref()))
 		.ok_or("No RPC secret provided")?;
 	let network_key = NetworkKey::from_slice(
 		&hex::decode(net_key_hex_str).err_context("Invalid RPC secret key (bad hex)")?[..],

src/model/garage.rs

@@ -159,7 +159,7 @@ impl Garage {
 		};
 
 		let network_key = NetworkKey::from_slice(
-			&hex::decode(&config.rpc_secret).expect("Invalid RPC secret key")[..],
+			&hex::decode(&config.rpc_secret.as_ref().unwrap()).expect("Invalid RPC secret key")[..],
 		)
 		.expect("Invalid RPC secret key");
 

src/util/config.rs

@@ -34,7 +34,10 @@ pub struct Config {
 	pub compression_level: Option<i32>,
 
 	/// RPC secret key: 32 bytes hex encoded
-	pub rpc_secret: String,
+	pub rpc_secret: Option<String>,
+
+	/// Optional file where RPC secret key is read from
+	pub rpc_secret_file: Option<String>,
 
 	/// Address to bind for RPC
 	pub rpc_bind_addr: SocketAddr,
@@ -177,7 +180,26 @@ pub fn read_config(config_file: PathBuf) -> Result<Config, Error> {
 	let mut config = String::new();
 	file.read_to_string(&mut config)?;
 
-	Ok(toml::from_str(&config)?)
+	let mut parsed_config: Config = toml::from_str(&config)?;
+
+	match (&parsed_config.rpc_secret, &parsed_config.rpc_secret_file) {
+		(Some(_), _) => {}
+		(None, Some(rpc_secret_file_path_string)) => {
+			let mut rpc_secret_file = std::fs::OpenOptions::new()
+				.read(true)
+				.open(rpc_secret_file_path_string)?;
+			let mut rpc_secret_from_file = String::new();
+			rpc_secret_file.read_to_string(&mut rpc_secret_from_file)?;
+			// trim_end: allows for use case such as `echo "$(openssl rand -hex 32)" > somefile`.
+			//           also editors sometimes add a trailing newline
+			parsed_config.rpc_secret = Some(String::from(rpc_secret_from_file.trim_end()));
+		}
+		(None, None) => {
+			return Err("either `rpc_secret` or `rpc_secret_file` needs to be set".into())
+		}
+	};
+
+	Ok(parsed_config)
 }
 
 fn default_compression() -> Option<i32> {