Rewrite entire codebase to split into client and server

src/server/command.rs

@@ -0,0 +1,77 @@
+use std::os::fd::FromRawFd;
+use std::path::PathBuf;
+
+use anyhow::Context;
+use clap::Parser;
+
+use std::os::unix::net::UnixStream as StdUnixStream;
+use tokio::net::UnixStream as TokioUnixStream;
+
+use crate::core::bootstrap::authenticated_unix_socket;
+use crate::core::common::UnixUser;
+use crate::server::config::read_config_from_path_with_arg_overrides;
+use crate::server::server_loop::listen_for_incoming_connections;
+use crate::server::{
+    config::{ServerConfig, ServerConfigArgs},
+    server_loop::handle_requests_for_single_session,
+};
+
+#[derive(Parser, Debug, Clone)]
+pub struct ServerArgs {
+    #[command(subcommand)]
+    subcmd: ServerCommand,
+
+    #[command(flatten)]
+    config_overrides: ServerConfigArgs,
+}
+
+#[derive(Parser, Debug, Clone)]
+pub enum ServerCommand {
+    #[command()]
+    Listen,
+
+    #[command()]
+    SocketActivate,
+}
+
+pub async fn handle_command(
+    socket_path: Option<PathBuf>,
+    config_path: Option<PathBuf>,
+    args: ServerArgs,
+) -> anyhow::Result<()> {
+    let config = read_config_from_path_with_arg_overrides(config_path, args.config_overrides)?;
+
+    // if let Err(e) = &result {
+    //     eprintln!("{}", e);
+    // }
+
+    match args.subcmd {
+        ServerCommand::Listen => listen_for_incoming_connections(socket_path, config).await,
+        ServerCommand::SocketActivate => socket_activate(config).await,
+    }
+}
+
+async fn socket_activate(config: ServerConfig) -> anyhow::Result<()> {
+    // TODO: allow getting socket path from other socket activation sources
+    let mut conn = get_socket_from_systemd().await?;
+    let uid = authenticated_unix_socket::server_authenticate(&mut conn).await?;
+    let unix_user = UnixUser::from_uid(uid.into())?;
+    handle_requests_for_single_session(conn, &unix_user, &config).await?;
+
+    Ok(())
+}
+
+async fn get_socket_from_systemd() -> anyhow::Result<TokioUnixStream> {
+    let fd = std::env::var("LISTEN_FDS")
+        .context("LISTEN_FDS not set, not running under systemd?")?
+        .parse::<i32>()
+        .context("Failed to parse LISTEN_FDS")?;
+
+    if fd != 1 {
+        return Err(anyhow::anyhow!("Unexpected LISTEN_FDS value: {}", fd));
+    }
+
+    let std_unix_stream = unsafe { StdUnixStream::from_raw_fd(fd) };
+    let socket = TokioUnixStream::from_std(std_unix_stream)?;
+    Ok(socket)
+}