From 0be84e7c52d6cd31c00f728df3fdd84e474519f6 Mon Sep 17 00:00:00 2001
From: G8XSU <3442979+G8XSU@users.noreply.github.com>
Date: Fri, 14 Mar 2025 09:56:59 -0700
Subject: [PATCH] Add file-based config support.

---
 rust/server/Cargo.toml             |  2 ++
 rust/server/src/main.rs            | 27 +++++++++++++++--
 rust/server/src/util/config.rs     | 48 ++++++++++++++++++++++++++++++
 rust/server/src/util/mod.rs        |  1 +
 rust/server/vss-server-config.toml | 10 +++++++
 5 files changed, 85 insertions(+), 3 deletions(-)
 create mode 100644 rust/server/src/util/config.rs
 create mode 100644 rust/server/src/util/mod.rs
 create mode 100644 rust/server/vss-server-config.toml

diff --git a/rust/server/Cargo.toml b/rust/server/Cargo.toml
index 8674aa8..5eec5a6 100644
--- a/rust/server/Cargo.toml
+++ b/rust/server/Cargo.toml
@@ -13,3 +13,5 @@ hyper-util = { version = "0.1", default-features = false, features = ["server-gr
 tokio = { version = "1.38.0", default-features = false, features = ["time", "signal", "rt-multi-thread", "macros"] }
 prost = { version = "0.11.6", default-features = false, features = ["std"] }
 bytes = "1.4.0"
+serde = { version = "1.0.203", default-features = false, features = ["derive"] }
+toml = { version = "0.8.9", default-features = false, features = ["parse"] }
diff --git a/rust/server/src/main.rs b/rust/server/src/main.rs
index 2b13a19..849dcee 100644
--- a/rust/server/src/main.rs
+++ b/rust/server/src/main.rs
@@ -23,11 +23,32 @@ use api::kv_store::KvStore;
 use impls::postgres_store::PostgresBackendImpl;
 use std::sync::Arc;
 
+pub(crate) mod util;
 pub(crate) mod vss_service;
 
 fn main() {
-	// Define the address to bind the server to
-	let addr = SocketAddr::from(([127, 0, 0, 1], 3000));
+	let args: Vec<String> = std::env::args().collect();
+	if args.len() != 2 {
+		eprintln!("Usage: {} <config-file-path>", args[0]);
+		std::process::exit(1);
+	}
+
+	let config = match util::config::load_config(&args[1]) {
+		Ok(cfg) => cfg,
+		Err(e) => {
+			eprintln!("Failed to load configuration: {}", e);
+			std::process::exit(1);
+		},
+	};
+
+	let addr: SocketAddr =
+		match format!("{}:{}", config.server_config.host, config.server_config.port).parse() {
+			Ok(addr) => addr,
+			Err(e) => {
+				eprintln!("Invalid host/port configuration: {}", e);
+				std::process::exit(1);
+			},
+		};
 
 	let runtime = match tokio::runtime::Builder::new_multi_thread().enable_all().build() {
 		Ok(runtime) => Arc::new(runtime),
@@ -47,7 +68,7 @@ fn main() {
 		};
 		let authorizer = Arc::new(NoopAuthorizer {});
 		let store = Arc::new(
-			PostgresBackendImpl::new("postgresql://postgres:postgres@localhost:5432/postgres")
+			PostgresBackendImpl::new(&config.postgresql_config.expect("PostgreSQLConfig must be defined in config file.").to_connection_string())
 				.await
 				.unwrap(),
 		);
diff --git a/rust/server/src/util/config.rs b/rust/server/src/util/config.rs
new file mode 100644
index 0000000..e75f972
--- /dev/null
+++ b/rust/server/src/util/config.rs
@@ -0,0 +1,48 @@
+use serde::Deserialize;
+
+#[derive(Deserialize)]
+pub(crate) struct Config {
+	pub(crate) server_config: ServerConfig,
+	pub(crate) postgresql_config: Option<PostgreSQLConfig>,
+}
+
+#[derive(Deserialize)]
+pub(crate) struct ServerConfig {
+	pub(crate) host: String,
+	pub(crate) port: u16,
+}
+
+#[derive(Deserialize)]
+pub(crate) struct PostgreSQLConfig {
+	pub(crate) username: Option<String>, // Optional in TOML, can be overridden by env
+	pub(crate) password: Option<String>, // Optional in TOML, can be overridden by env
+	pub(crate) host: String,
+	pub(crate) port: u16,
+	pub(crate) database: String,
+}
+
+impl PostgreSQLConfig {
+	pub(crate) fn to_connection_string(&self) -> String {
+		let username_env = std::env::var("VSS_POSTGRESQL_USERNAME");
+		let username = username_env.as_ref()
+			.ok()
+			.or_else(|| self.username.as_ref())
+			.expect("PostgreSQL database username must be provided in config or env var VSS_POSTGRESQL_USERNAME must be set.");
+		let password_env = std::env::var("VSS_POSTGRESQL_PASSWORD");
+		let password = password_env.as_ref()
+			.ok()
+			.or_else(|| self.password.as_ref())
+			.expect("PostgreSQL database password must be provided in config or env var VSS_POSTGRESQL_PASSWORD must be set.");
+
+		format!(
+			"postgresql://{}:{}@{}:{}/{}",
+			username, password, self.host, self.port, self.database
+		)
+	}
+}
+
+pub(crate) fn load_config(config_path: &str) -> Result<Config, Box<dyn std::error::Error>> {
+	let config_str = std::fs::read_to_string(config_path)?;
+	let config: Config = toml::from_str(&config_str)?;
+	Ok(config)
+}
diff --git a/rust/server/src/util/mod.rs b/rust/server/src/util/mod.rs
new file mode 100644
index 0000000..30e489d
--- /dev/null
+++ b/rust/server/src/util/mod.rs
@@ -0,0 +1 @@
+pub(crate) mod config;
diff --git a/rust/server/vss-server-config.toml b/rust/server/vss-server-config.toml
new file mode 100644
index 0000000..8a013b5
--- /dev/null
+++ b/rust/server/vss-server-config.toml
@@ -0,0 +1,10 @@
+[server_config]
+host = "127.0.0.1"
+port = 8080
+
+[postgresql_config]
+username = "postgres"  # Optional in TOML, can be overridden by env var `VSS_POSTGRESQL_USERNAME`
+password = "postgres"  # Optional in TOML, can be overridden by env var `VSS_POSTGRESQL_PASSWORD`
+host = "localhost"
+port = 5432
+database = "postgres"