Improve config system

Add pkl to generate configs

emgauwa-lib/Cargo.toml

@@ -25,3 +25,4 @@ sqlx = { version = "0.7", features = ["sqlite", "runtime-tokio", "macros", "chro
 libsqlite3-sys = { version = "*", features = ["bundled"] }
 uuid = "1.6"
 futures = "0.3"
+libc = "0.2"

emgauwa-lib/build.rs

@@ -1,4 +1,4 @@
 fn main() {
 	println!("cargo:rerun-if-changed=migrations");
-	println!("cargo:rustc-env=DATABASE_URL=sqlite://emgauwa-dev.sqlite");
+	println!("cargo:rustc-env=DATABASE_URL=sqlite://_local/emgauwa-dev.sqlite");
 }

emgauwa-lib/src/lib.rs

@@ -2,5 +2,6 @@ pub mod constants;
 pub mod db;
 pub mod errors;
 pub mod models;
+pub mod settings;
 pub mod types;
 pub mod utils;

emgauwa-lib/src/settings.rs

@@ -0,0 +1,77 @@
+use serde_derive::Deserialize;
+
+use crate::constants;
+use crate::errors::EmgauwaError;
+
+#[derive(Clone, Debug, Deserialize)]
+#[serde(default)]
+#[allow(unused)]
+pub struct Server {
+	pub host: String,
+	pub port: u16,
+}
+
+#[derive(Clone, Debug, Deserialize)]
+#[serde(default)]
+#[allow(unused)]
+pub struct Logging {
+	pub level: String,
+	pub file: String,
+}
+
+#[derive(Clone, Debug, Deserialize)]
+#[serde(default)]
+#[allow(unused)]
+pub struct Permissions {
+	pub user: String,
+	pub group: String,
+}
+
+impl Default for Server {
+	fn default() -> Self {
+		Server {
+			host: String::from("127.0.0.1"),
+			port: constants::DEFAULT_PORT,
+		}
+	}
+}
+
+impl Default for Logging {
+	fn default() -> Self {
+		Logging {
+			level: String::from("info"),
+			file: String::from("stdout"),
+		}
+	}
+}
+
+impl Default for Permissions {
+	fn default() -> Self {
+		Permissions {
+			user: String::from(""),
+			group: String::from(""),
+		}
+	}
+}
+
+pub fn load<T>(config_name: &str, env_prefix: &str) -> Result<T, EmgauwaError>
+where
+	for<'de> T: serde::Deserialize<'de>,
+{
+	// TODO: Add switch to only include local config if in development mode
+	let dev_file =
+		config::File::with_name(&format!("./_local/emgauwa-{}", config_name)).required(false);
+	let local_file = config::File::with_name(&format!("./emgauwa-{}", config_name)).required(false);
+
+	config::Config::builder()
+		.add_source(dev_file)
+		.add_source(local_file)
+		.add_source(
+			config::Environment::with_prefix(&format!("EMGAUWA_{}", env_prefix))
+				.prefix_separator("__")
+				.separator("__"),
+		)
+		.build()?
+		.try_deserialize::<T>()
+		.map_err(EmgauwaError::from)
+}

emgauwa-lib/src/utils.rs

@@ -1,3 +1,5 @@
+use std::ffi::CString;
+use std::io::{Error, ErrorKind};
 use std::str::FromStr;
 
 use chrono::Datelike;
@@ -5,25 +7,9 @@ use log::LevelFilter;
 use simple_logger::SimpleLogger;
 
 use crate::errors::EmgauwaError;
+use crate::settings::Permissions;
 use crate::types::Weekday;
 
-pub fn load_settings<T>(config_name: &str, env_prefix: &str) -> Result<T, EmgauwaError>
-where
-	for<'de> T: serde::Deserialize<'de>,
-{
-	let default_file = config::File::with_name(&format!("emgauwa-{}", config_name)).required(false);
-
-	config::Config::builder()
-		.add_source(default_file)
-		.add_source(
-			config::Environment::with_prefix(&format!("EMGAUWA_{}", env_prefix))
-				.prefix_separator("__")
-				.separator("__"),
-		)
-		.build()?
-		.try_deserialize::<T>()
-		.map_err(EmgauwaError::from)
-}
 
 pub fn init_logging(level: &str) -> Result<(), EmgauwaError> {
 	let log_level: LevelFilter = LevelFilter::from_str(level)
@@ -38,6 +24,67 @@ pub fn init_logging(level: &str) -> Result<(), EmgauwaError> {
 	Ok(())
 }
 
+// https://blog.lxsang.me/post/id/28.0
+pub fn drop_privileges(permissions: &Permissions) -> Result<(), Error> {
+	log::info!(
+		"Dropping privileges to {}:{}",
+		permissions.user,
+		permissions.group
+	);
+
+	// the group id need to be set first, because, when the user privileges drop,
+	// we are unable to drop the group privileges
+	if !permissions.group.is_empty() {
+		drop_privileges_group(&permissions.group)?;
+	}
+	if !permissions.user.is_empty() {
+		drop_privileges_user(&permissions.user)?;
+	}
+	Ok(())
+}
+
+fn drop_privileges_group(group: &str) -> Result<(), Error> {
+	// get the gid from username
+	if let Ok(cstr) = CString::new(group.as_bytes()) {
+		let p = unsafe { libc::getgrnam(cstr.as_ptr()) };
+		if p.is_null() {
+			log::error!("Unable to getgrnam of group: {}", group);
+			return Err(Error::last_os_error());
+		}
+		if unsafe { libc::setgid((*p).gr_gid) } != 0 {
+			log::error!("Unable to setgid of group: {}", group);
+			return Err(Error::last_os_error());
+		}
+	} else {
+		return Err(Error::new(
+			ErrorKind::Other,
+			"Cannot create CString from String (group)!",
+		));
+	}
+	Ok(())
+}
+
+fn drop_privileges_user(user: &str) -> Result<(), Error> {
+	// get the uid from username
+	if let Ok(cstr) = CString::new(user.as_bytes()) {
+		let p = unsafe { libc::getpwnam(cstr.as_ptr()) };
+		if p.is_null() {
+			log::error!("Unable to getpwnam of user: {}", user);
+			return Err(Error::last_os_error());
+		}
+		if unsafe { libc::setuid((*p).pw_uid) } != 0 {
+			log::error!("Unable to setuid of user: {}", user);
+			return Err(Error::last_os_error());
+		}
+	} else {
+		return Err(Error::new(
+			ErrorKind::Other,
+			"Cannot create CString from String (user)!",
+		));
+	}
+	Ok(())
+}
+
 pub fn get_weekday() -> Weekday {
 	(chrono::offset::Local::now()
 		.date_naive()