main.rs cleanup

src/main.rs

@@ -12,75 +12,158 @@ mod api;
 mod config;
 mod error;
 mod machine;
+mod session;
+
+use signal_hook::iterator::Signals;
+
+use clap::{App, Arg};
 
 use api::api as api_capnp;
 
-use futures::prelude::*;
-use futures_signals::signal::Mutable;
-use futures::task::LocalSpawn;
+use session::Session;
 
-fn main() {
-    let log = log::init();
+use futures::prelude::*;
+use futures::executor::{LocalPool, ThreadPool};
+use futures::join;
+
+use capnp_rpc::twoparty::{VatNetwork, VatId};
+use capnp_rpc::rpc_twoparty_capnp::Side;
+
+use async_std::net::{TcpListener, TcpStream};
+
+use std::io;
+use std::io::Write;
+use std::path::PathBuf;
+use std::str::FromStr;
+use std::mem::drop;
+
+use std::sync::Arc;
+
+use error::Error;
+
+// Returning a `Result` from `main` allows us to use the `?` shorthand.
+// In the case of an Err it will be printed using `fmt::Debug`
+fn main() -> Result<(), Error> {
+    // Initialize signal handler.
+    // Specifically, this is a Stream of c_int representing received signals
+    // We currently only care about Ctrl-C so SIGINT it is.
+    // TODO: Make this do SIGHUP and a few others too.
+    let signals = Signals::new(&[signal_hook::SIGINT])?.into_async()?;
+
+    use clap::{crate_version, crate_description, crate_name};
+
+    // Argument parsing
+    // values for the name, description and version are pulled from `Cargo.toml`.
+    let matches = App::new(crate_name!())
+        .about(crate_description!())
+        .version(crate_version!())
+        .arg(Arg::with_name("config")
+            .help("Path to the config file to use")
+            .long("config")
+            .short("c")
+            .takes_value(true)
+        )
+        .arg(Arg::with_name("print default")
+            .help("Print a default config to stdout instead of running")
+            .long("print-default")
+        )
+        .get_matches();
+
+    // Check for the --print-default option first because we don't need to do anything else in that
+    // case.
+    if matches.is_present("print default") {
+        let config = config::Config::default();
+        let encoded = toml::to_vec(&config)?;
+
+        // Direct writing to fd 1 is faster but also prevents any print-formatting that could
+        // invalidate the generated TOML
+        let stdout = io::stdout();
+        let mut handle = stdout.lock();
+        handle.write_all(&encoded)?;
+
+        // Early return to exit.
+        return Ok(())
+    }
+
+    // If no `config` option is given use a preset default.
+    let configpath = matches.value_of("config").unwrap_or("/etc/diflouroborane.toml");
+    let config = config::read(&PathBuf::from_str(configpath).unwrap())?;
+
+    // Initialize the logging subsystem first to be able to better document the progress from now
+    // on.
+    // TODO: Now would be a really good time to close stdin/out and move logging to syslog
+    // Log is in an Arc so we can do very cheap clones in closures.
+    let log = Arc::new(log::init(&config));
     info!(log, "Starting");
 
-    let config = config::read().unwrap();
+    // Kick up an executor
+    // Most initializations from now on do some amount of IO and are much better done in an
+    // asyncronous fashion.
+    let mut exec = LocalPool::new();
 
-    modules::init(log.new(o!()));
-    api::init();
+    // Start loading the machine database, authentication system and permission system
+    // All of those get a custom logger so the source of a log message can be better traced and
+    // filtered
+    let machinedb_f = machine::init(log.new(o!("system" => "machinedb")), &config);
+    let permission_f = access::init(log.new(o!("system" => "permissions")), &config);
+    let authentication_f = auth::init(log.new(o!("system" => "authentication")), &config);
 
-    let m = machine::init(&config).unwrap();
-    let m = Mutable::new(m);
-    let m2 = m.clone();
-    let c2 = config.clone();
+    // Bind to each address in config.listen.
+    // This is a Stream over Futures so it will do absolutely nothing unless polled to completion
+    let listeners_s: futures::stream::Collect<_, Vec<TcpListener>> = stream::iter((&config).listen.iter())
+        .map(|l| {
+            let addr = l.address.clone();
+            TcpListener::bind((l.address.as_str(), l.port.unwrap_or(config::DEFAULT_PORT)))
+                // If the bind errors, include the address so we can log it
+                // Since this closure is lazy we need to have a cloned addr
+                .map_err(|e| { (addr, e) })
+        })
+        .filter_map(|f| async {
+            match f.await {
+                Ok(l) => Some(l),
+                Err((addr, e)) => {
+                    error!(&log, "Could not connect to {}: {}", addr, e);
+                    None
+                }
+            }
+        }).collect();
 
-
-    let mut exec = futures::executor::LocalPool::new();
-
-    let enf = exec.run_until(async {
-        let e = access::init(&config).await.unwrap();
-        Mutable::new(e)
+    let (mdb, pdb, auth) = exec.run_until(async {
+        // Rull all futures to completion in parallel.
+        // This will "block" until all three are done starting up.
+        join!(machinedb_f, permission_f, authentication_f)
     });
 
-    let p = auth::open_passdb(&config.passdb).unwrap();
-    let p = Mutable::new(p);
-    let authp = auth::AuthenticationProvider::new(p, enf.clone());
-    let authp = Mutable::new(authp);
+    // Error out if any of the subsystems failed to start.
+    let mdb = mdb?;
+    let pdb = pdb.unwrap();
+    let auth = auth?;
 
-    use std::net::ToSocketAddrs;
-    let args: Vec<String> = ::std::env::args().collect();
-    if args.len() != 2 {
-        println!("usage: {} ADDRESS[:PORT]", args[0]);
-        return;
-    }
+    // Since the below closures will happen at a much later time we need to make sure all pointers
+    // are still valid. Thus, Arc.
+    let l2 = log.clone();
+    let l3 = log.clone();
 
-    let addr = args[1].to_socket_addrs().unwrap().next().expect("could not parse address");
+    // Create a thread pool to run tasks on
+    let mut pool = ThreadPool::builder()
+        .after_start(move |i| { info!(l2.new(o!("system" => "threadpool")), "Starting Thread <{}>", i)})
+        .before_stop(move |i| { info!(l3.new(o!("system" => "threadpool")), "Stopping Thread <{}>", i)})
+        .create()?;
 
-    let permlog = log.new(o!());
-    let machlog = log.new(o!());
+    // Spawner is a handle to the shared ThreadPool forwarded into each connection
+    let spawner = pool.clone();
 
-    machine::save(&c2, &m2.lock_ref()).expect("MachineDB save");
-
-    let spawner = exec.spawner();
     let result: Result<(), Box<dyn std::error::Error>> = exec.run_until(async move {
-        let listener = async_std::net::TcpListener::bind(&addr).await?;
-        let mut incoming = listener.incoming();
-        while let Some(socket) = incoming.next().await {
-            let socket = socket?;
-            trace!(log, "New connection from {:?}", socket.peer_addr());
-            // TODO: Prettify session handling
-            let auth = auth::Authentication::new(authp.clone());
-            trace!(log, "Init auth");
-            let perm = access::Permissions::new(permlog.clone(), enf.clone(), auth.clone());
-            trace!(log, "Init perm");
-            let mach = machine::Machines::new(machlog.clone(), m.clone(), perm.clone());
-            trace!(log, "Init mach");
+        // Generate a stream of TcpStreams appearing on any of the interfaces we listen to
+        let listeners = listeners_s.await;
+        let mut incoming = stream::select_all(listeners.iter().map(|l| l.incoming()));
 
-            let rpc_system = api::process_socket(auth, perm, mach, socket);
-            spawner.spawn_local_obj(
-                Box::pin(rpc_system.map_err(|e| println!("error: {:?}", e)).map(|_|())).into()).expect("spawn")
+        // Runn
+        while let Some(socket) = incoming.next().await {
         }
+
         Ok(())
     });
-    result.expect("main");
 
+    Ok(())
 }