basic netns management

src/daemon/mod.rs

@@ -0,0 +1,55 @@
+mod namespace;
+
+use crate::config::{Config, NamespaceName};
+use crate::daemon::namespace::{NamespaceError, NetNs};
+use main_error::MainResult;
+use sd_notify::{notify, NotifyState};
+use std::io::Error as IoError;
+use thiserror::Error;
+use tokio::runtime::Runtime;
+use tokio::signal::ctrl_c;
+
+pub fn daemon(config: Config) -> MainResult {
+    let rt = Runtime::new()?;
+    Ok(rt.block_on(daemon_async(config))?)
+}
+
+async fn daemon_async(config: Config) -> Result<(), DaemonError> {
+    for namespace in &config.namespaces {
+        println!("{}:", namespace.name);
+        for forward in &namespace.forward {
+            println!("  {} => {}", forward.source, forward.destination);
+        }
+    }
+
+    let namespaces = config
+        .namespaces
+        .iter()
+        .map(|ns| ActiveNamespace::new(&ns.name))
+        .collect::<Result<Vec<_>, _>>()?;
+    
+    // now the namespaces are setup, we can tell systemd to start any service depending on them
+    notify(true, &[NotifyState::Ready]).map_err(DaemonError::Notify)?;
+
+    let _ = ctrl_c().await;
+    Ok(())
+}
+
+struct ActiveNamespace {
+    ns: NetNs,
+}
+
+impl ActiveNamespace {
+    pub fn new(name: &NamespaceName) -> Result<Self, DaemonError> {
+        let ns = NetNs::new(name)?;
+        Ok(ActiveNamespace { ns })
+    }
+}
+
+#[derive(Debug, Error)]
+pub enum DaemonError {
+    #[error(transparent)]
+    Namespace(#[from] NamespaceError),
+    #[error("Error sending notification to systemd: {0:#}")]
+    Notify(IoError)
+}