add web terminal emulator (closes #6)

Cargo.lock

@@ -76,7 +76,7 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5ca11d4be1bab0c8bc8734a9aa7bf4ee8316d462a08c6ac5052f888fef5b494b"
 dependencies = [
- "windows-sys",
+ "windows-sys 0.48.0",
 ]
 
 [[package]]
@@ -86,7 +86,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f0699d10d2f4d628a98ee7b57b289abbc98ff3bad977cb3152709d4bf2330628"
 dependencies = [
  "anstyle",
- "windows-sys",
+ "windows-sys 0.48.0",
 ]
 
 [[package]]
@@ -250,7 +250,7 @@ dependencies = [
  "js-sys",
  "num-traits",
  "wasm-bindgen",
- "windows-targets",
+ "windows-targets 0.48.5",
 ]
 
 [[package]]
@@ -334,12 +334,12 @@ checksum = "5443807d6dff69373d433ab9ef5378ad8df50ca6298caf15de6e52e24aaf54d5"
 
 [[package]]
 name = "errno"
-version = "0.3.7"
+version = "0.3.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f258a7194e7f7c2a7837a8913aeab7fd8c383457034fa20ce4dd3dcb813e8eb8"
+checksum = "a258e46cdc063eb8519c00b9fc845fc47bcfca4130e2f08e88665ceda8474245"
 dependencies = [
  "libc",
- "windows-sys",
+ "windows-sys 0.52.0",
 ]
 
 [[package]]
@@ -483,7 +483,7 @@ version = "0.5.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5444c27eef6923071f7ebcc33e3444508466a76f7a2b93da00ed6e19f30c1ddb"
 dependencies = [
- "windows-sys",
+ "windows-sys 0.48.0",
 ]
 
 [[package]]
@@ -653,9 +653,9 @@ checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
 [[package]]
 name = "libc"
-version = "0.2.150"
+version = "0.2.151"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "89d92a4743f9a61002fae18374ed11e7973f530cb3a3255fb354818118b2203c"
+checksum = "302d7ab3130588088d277783b1e2d2e10c9e9e4a16dd9050e6ec93fb3e7048f4"
 
 [[package]]
 name = "linux-raw-sys"
@@ -663,6 +663,16 @@ version = "0.4.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "969488b55f8ac402214f3f5fd243ebb7206cf82de60d3172994707a4bcc2b829"
 
+[[package]]
+name = "lock_api"
+version = "0.4.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3c168f8615b12bc01f9c17e2eb0cc07dcae1940121185446edc3744920e8ef45"
+dependencies = [
+ "autocfg",
+ "scopeguard",
+]
+
 [[package]]
 name = "log"
 version = "0.4.20"
@@ -704,7 +714,7 @@ checksum = "3dce281c5e46beae905d4de1870d8b1509a9142b62eedf18b443b011ca8343d0"
 dependencies = [
  "libc",
  "wasi",
- "windows-sys",
+ "windows-sys 0.48.0",
 ]
 
 [[package]]
@@ -772,6 +782,29 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b15813163c1d831bf4a13c3610c05c0d03b39feb07f7e09fa234dac9b15aaf39"
 
+[[package]]
+name = "parking_lot"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3742b2c103b9f06bc9fff0a37ff4912935851bee6d36f3c02bcc755bcfec228f"
+dependencies = [
+ "lock_api",
+ "parking_lot_core",
+]
+
+[[package]]
+name = "parking_lot_core"
+version = "0.9.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4c42a9226546d68acdd9c0a280d17ce19bfe27a46bf68784e4066115788d008e"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "redox_syscall",
+ "smallvec",
+ "windows-targets 0.48.5",
+]
+
 [[package]]
 name = "percent-encoding"
 version = "2.3.0"
@@ -912,6 +945,7 @@ dependencies = [
  "prost",
  "regex",
  "reqwest",
+ "rustix",
  "serde",
  "serde_json",
  "sysinfo",
@@ -1045,15 +1079,16 @@ checksum = "d626bb9dae77e28219937af045c257c28bfd3f69333c512553507f5f9798cb76"
 
 [[package]]
 name = "rustix"
-version = "0.38.24"
+version = "0.38.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9ad981d6c340a49cdc40a1028d9c6084ec7e9fa33fcb839cab656a267071e234"
+checksum = "72e572a5e8ca657d7366229cdde4bd14c4eb5499a9573d4d366fe1b599daa316"
 dependencies = [
  "bitflags 2.4.1",
  "errno",
+ "itoa",
  "libc",
  "linux-raw-sys",
- "windows-sys",
+ "windows-sys 0.52.0",
 ]
 
 [[package]]
@@ -1068,6 +1103,12 @@ version = "1.0.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1ad4cc8da4ef723ed60bced201181d83791ad433213d8c24efffda1eec85d741"
 
+[[package]]
+name = "scopeguard"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
+
 [[package]]
 name = "serde"
 version = "1.0.192"
@@ -1161,7 +1202,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7b5fac59a5cb5dd637972e5fca70daf0523c9067fcdc4842f053dae04a18f8e9"
 dependencies = [
  "libc",
- "windows-sys",
+ "windows-sys 0.48.0",
 ]
 
 [[package]]
@@ -1232,7 +1273,7 @@ dependencies = [
  "fastrand",
  "redox_syscall",
  "rustix",
- "windows-sys",
+ "windows-sys 0.48.0",
 ]
 
 [[package]]
@@ -1271,11 +1312,12 @@ dependencies = [
  "libc",
  "mio",
  "num_cpus",
+ "parking_lot",
  "pin-project-lite",
  "signal-hook-registry",
  "socket2 0.5.5",
  "tokio-macros",
- "windows-sys",
+ "windows-sys 0.48.0",
 ]
 
 [[package]]
@@ -1654,7 +1696,7 @@ version = "0.51.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f1f8cf84f35d2db49a46868f947758c7a1138116f7fac3bc844f43ade1292e64"
 dependencies = [
- "windows-targets",
+ "windows-targets 0.48.5",
 ]
 
 [[package]]
@@ -1663,7 +1705,16 @@ version = "0.48.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "677d2418bec65e3338edb076e806bc1ec15693c5d0104683f2efe857f61056a9"
 dependencies = [
- "windows-targets",
+ "windows-targets 0.48.5",
+]
+
+[[package]]
+name = "windows-sys"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+dependencies = [
+ "windows-targets 0.52.0",
 ]
 
 [[package]]
@@ -1672,13 +1723,28 @@ version = "0.48.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9a2fa6e2155d7247be68c096456083145c183cbbbc2764150dda45a87197940c"
 dependencies = [
- "windows_aarch64_gnullvm",
+ "windows_aarch64_gnullvm 0.48.5",
- "windows_aarch64_msvc",
+ "windows_aarch64_msvc 0.48.5",
- "windows_i686_gnu",
+ "windows_i686_gnu 0.48.5",
- "windows_i686_msvc",
+ "windows_i686_msvc 0.48.5",
- "windows_x86_64_gnu",
+ "windows_x86_64_gnu 0.48.5",
- "windows_x86_64_gnullvm",
+ "windows_x86_64_gnullvm 0.48.5",
- "windows_x86_64_msvc",
+ "windows_x86_64_msvc 0.48.5",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a18201040b24831fbb9e4eb208f8892e1f50a37feb53cc7ff887feb8f50e7cd"
+dependencies = [
+ "windows_aarch64_gnullvm 0.52.0",
+ "windows_aarch64_msvc 0.52.0",
+ "windows_i686_gnu 0.52.0",
+ "windows_i686_msvc 0.52.0",
+ "windows_x86_64_gnu 0.52.0",
+ "windows_x86_64_gnullvm 0.52.0",
+ "windows_x86_64_msvc 0.52.0",
 ]
 
 [[package]]
@@ -1687,42 +1753,84 @@ version = "0.48.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2b38e32f0abccf9987a4e3079dfb67dcd799fb61361e53e2882c3cbaf0d905d8"
 
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cb7764e35d4db8a7921e09562a0304bf2f93e0a51bfccee0bd0bb0b666b015ea"
+
 [[package]]
 name = "windows_aarch64_msvc"
 version = "0.48.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dc35310971f3b2dbbf3f0690a219f40e2d9afcf64f9ab7cc1be722937c26b4bc"
 
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbaa0368d4f1d2aaefc55b6fcfee13f41544ddf36801e793edbbfd7d7df075ef"
+
 [[package]]
 name = "windows_i686_gnu"
 version = "0.48.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a75915e7def60c94dcef72200b9a8e58e5091744960da64ec734a6c6e9b3743e"
 
+[[package]]
+name = "windows_i686_gnu"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a28637cb1fa3560a16915793afb20081aba2c92ee8af57b4d5f28e4b3e7df313"
+
 [[package]]
 name = "windows_i686_msvc"
 version = "0.48.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8f55c233f70c4b27f66c523580f78f1004e8b5a8b659e05a4eb49d4166cca406"
 
+[[package]]
+name = "windows_i686_msvc"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ffe5e8e31046ce6230cc7215707b816e339ff4d4d67c65dffa206fd0f7aa7b9a"
+
 [[package]]
 name = "windows_x86_64_gnu"
 version = "0.48.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "53d40abd2583d23e4718fddf1ebec84dbff8381c07cae67ff7768bbf19c6718e"
 
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3d6fa32db2bc4a2f5abeacf2b69f7992cd09dca97498da74a151a3132c26befd"
+
 [[package]]
 name = "windows_x86_64_gnullvm"
 version = "0.48.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0b7b52767868a23d5bab768e390dc5f5c55825b6d30b86c844ff2dc7414044cc"
 
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1a657e1e9d3f514745a572a6846d3c7aa7dbe1658c056ed9c3344c4109a6949e"
+
 [[package]]
 name = "windows_x86_64_msvc"
 version = "0.48.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ed94fce61571a4006852b7389a063ab983c02eb1bb37b47f8272ce92d06d9538"
 
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dff9641d1cd4be8d1a070daf9e3773c5f67e78b4d9d42263020c057706765c04"
+
 [[package]]
 name = "winreg"
 version = "0.50.0"
@@ -1730,5 +1838,5 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "524e57b2c537c0f9b1e69f1965311ec12182b4122e45035b1508cd24d2adadb1"
 dependencies = [
  "cfg-if",
- "windows-sys",
+ "windows-sys 0.48.0",
 ]

agent/Cargo.toml

@@ -13,10 +13,11 @@ once_cell = "1.18.0"
 prost = "0.12.1"
 regex = "1.10.2"
 reqwest = { version = "0.11.18", features = ["blocking", "json"], default-features = false }
+rustix = { version = "0.38.28", features = ["fs", "process", "pty", "stdio", "termios"] }
 serde = { version = "1.0.173", features = ["derive"] }
 serde_json = "1.0.103"
 sysinfo = { version = "0.29.2", default-features = false }
-tokio = { version = "1.28.2", features = ["rt-multi-thread", "io-util", "process", "macros", "signal"] }
+tokio = { version = "1.28.2", features = ["full"] }
 tokio-stream = { version = "0.1.14", features = ["net", "sync"] }
 tokio-util = { version = "0.7.10", features = ["codec"] }
 tonic = { version = "0.10.2" }

agent/src/lib.rs

@@ -2,6 +2,7 @@ pub mod config;
 pub mod debian;
 pub mod health;
 pub mod info;
+pub mod pty;
 pub mod self_update;
 pub mod server;
 pub mod task;

agent/src/pty.rs

@@ -0,0 +1,166 @@
+use std::{io, task::ready};
+
+use rustix::{
+    fd::OwnedFd,
+    fs::{fcntl_getfl, fcntl_setfl, OFlags},
+    process::{ioctl_tiocsctty, setsid},
+    pty::{grantpt, ioctl_tiocgptpeer, openpt, unlockpt, OpenptFlags},
+    stdio::{dup2_stderr, dup2_stdin, dup2_stdout},
+    termios::{tcsetwinsize, Winsize},
+};
+use tokio::{
+    io::{unix::AsyncFd, AsyncRead, AsyncWrite},
+    process::Child,
+};
+
+#[derive(Debug)]
+pub struct Pty {
+    fd: AsyncFd<OwnedFd>,
+}
+
+impl Pty {
+    pub fn open() -> io::Result<Self> {
+        let master = openpt(OpenptFlags::RDWR | OpenptFlags::NOCTTY | OpenptFlags::CLOEXEC)?;
+        grantpt(&master)?;
+        unlockpt(&master)?;
+
+        // Set nonblocking
+        let flags = fcntl_getfl(&master)?;
+        fcntl_setfl(&master, flags | OFlags::NONBLOCK)?;
+
+        let fd = AsyncFd::new(master)?;
+
+        Ok(Self { fd })
+    }
+
+    pub fn child(&self) -> io::Result<PtyChild> {
+        // NOTE: Linux v4.13 and above
+        let fd = ioctl_tiocgptpeer(&self.fd, OpenptFlags::RDWR | OpenptFlags::NOCTTY)?;
+        let child = PtyChild { fd };
+
+        Ok(child)
+    }
+
+    pub fn resize_window(&self, rows: u16, cols: u16) -> io::Result<()> {
+        let winsize = Winsize {
+            ws_row: rows,
+            ws_col: cols,
+            ws_xpixel: 0,
+            ws_ypixel: 0,
+        };
+
+        tcsetwinsize(&self.fd, winsize)?;
+
+        Ok(())
+    }
+
+    pub fn try_clone(&self) -> io::Result<Pty> {
+        let fd = self.fd.get_ref().try_clone()?;
+
+        Ok(Pty {
+            fd: AsyncFd::new(fd)?,
+        })
+    }
+}
+
+impl AsyncRead for Pty {
+    fn poll_read(
+        self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+        buf: &mut tokio::io::ReadBuf<'_>,
+    ) -> std::task::Poll<io::Result<()>> {
+        loop {
+            let mut guard = ready!(self.fd.poll_read_ready(cx)?);
+
+            match guard.try_io(|inner| {
+                let fd = inner.get_ref();
+                let n = rustix::io::read(fd, buf.initialize_unfilled())?;
+                buf.advance(n);
+
+                Ok(())
+            }) {
+                Ok(result) => return std::task::Poll::Ready(result),
+                Err(_would_block) => continue,
+            }
+        }
+    }
+}
+
+impl AsyncWrite for Pty {
+    fn poll_write(
+        self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+        buf: &[u8],
+    ) -> std::task::Poll<Result<usize, io::Error>> {
+        loop {
+            let mut guard = ready!(self.fd.poll_write_ready(cx))?;
+
+            match guard.try_io(|inner| Ok(rustix::io::write(inner.get_ref(), buf)?)) {
+                Ok(result) => return std::task::Poll::Ready(result),
+                Err(_would_block) => continue,
+            }
+        }
+    }
+
+    fn poll_flush(
+        self: std::pin::Pin<&mut Self>,
+        _cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Result<(), io::Error>> {
+        std::task::Poll::Ready(Ok(()))
+    }
+
+    fn poll_shutdown(
+        self: std::pin::Pin<&mut Self>,
+        _cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Result<(), io::Error>> {
+        std::task::Poll::Ready(Ok(()))
+    }
+}
+
+#[derive(Debug)]
+pub struct PtyChild {
+    fd: OwnedFd,
+}
+
+impl PtyChild {
+    pub fn login_tty(&self) -> io::Result<()> {
+        setsid()?;
+        ioctl_tiocsctty(&self.fd)?;
+        dup2_stdin(&self.fd)?;
+        dup2_stdout(&self.fd)?;
+        dup2_stderr(&self.fd)?;
+
+        Ok(())
+    }
+}
+
+pub fn open_shell(pty_child: PtyChild) -> io::Result<Child> {
+    let mut cmd = tokio::process::Command::new("/bin/bash");
+
+    unsafe {
+        cmd.pre_exec(move || {
+            pty_child.login_tty()?;
+            Ok(())
+        });
+    }
+
+    cmd.spawn()
+}
+
+#[cfg(test)]
+mod test {
+    use rustix::fd::AsRawFd;
+
+    use super::*;
+
+    #[tokio::test]
+    async fn can_open_pty() {
+        let pty = Pty::open().unwrap();
+        let child = pty.child().unwrap();
+
+        let master_fd = pty.fd.get_ref().as_raw_fd();
+        let child_fd = child.fd.as_raw_fd();
+
+        assert!(master_fd != child_fd);
+    }
+}

agent/src/server/agent.rs

@@ -1,14 +1,20 @@
 use std::{pin::Pin, process::Stdio, sync::Mutex};
 
-use tokio::process::Command;
+use tokio::{io::AsyncWriteExt, process::Command};
 use tokio_stream::{
     wrappers::{ReceiverStream, WatchStream},
     Stream, StreamExt,
 };
 use tokio_util::codec::{BytesCodec, FramedRead};
-use tonic::{Request, Response, Status};
+use tonic::{Request, Response, Status, Streaming};
 
-use crate::{debian, health::HealthMonitor, info::Info, task::TaskBuilder};
+use crate::{
+    debian,
+    health::HealthMonitor,
+    info::Info,
+    pty::{open_shell, Pty},
+    task::TaskBuilder,
+};
 
 use super::proto::*;
 
@@ -168,4 +174,51 @@ impl agent_server::Agent for AgentService<'static> {
 
         Ok(Response::new(Box::pin(stream)))
     }
+
+    type TerminalStream = Pin<Box<dyn Stream<Item = Result<TerminalResponse, Status>> + Send>>;
+
+    async fn terminal(
+        &self,
+        req: Request<Streaming<TerminalRequest>>,
+    ) -> AgentResult<Self::TerminalStream> {
+        let mut in_stream = req.into_inner();
+        let mut pty = Pty::open()?;
+        let pty_clone = pty.try_clone()?;
+        let pty_child = pty.child()?;
+        let mut child = open_shell(pty_child)?;
+
+        tokio::spawn(async move {
+            // TODO: Handle errors inside here
+            while let Some(result) = in_stream.next().await {
+                match result {
+                    Ok(req) => {
+                        if let Some(resize) = req.resize {
+                            pty.resize_window(resize.rows as u16, resize.cols as u16)
+                                .unwrap();
+                        }
+
+                        pty.write_all(&req.input[..]).await.unwrap();
+                    }
+                    Err(err) => {
+                        // Log and ignore the error...
+                        tracing::warn!(%err, "received an incoming stream error");
+                    }
+                }
+            }
+
+            // TODO: Maybe there's a more graceful way to stop the process?
+            child.kill().await.unwrap();
+        });
+
+        let out_stream = FramedRead::new(pty_clone, BytesCodec::new()).map(|inner| {
+            inner
+                .map(|b| TerminalResponse { output: b.to_vec() })
+                .map_err(|err| {
+                    tracing::error!(%err, "read error on pseudoterminal");
+                    Status::internal("terminal read error")
+                })
+        });
+
+        Ok(Response::new(Box::pin(out_stream)))
+    }
 }

app/assets/css/app.css

@@ -1,5 +1,6 @@
 @import "tailwindcss/base";
 @import "tailwindcss/components";
 @import "tailwindcss/utilities";
+@import "xterm";
 
 /* This file is for your main application CSS */

app/assets/js/app.js

@@ -2,42 +2,68 @@
 // to get started and then uncomment the line below.
 // import "./user_socket.js"
 
-// You can include dependencies in two ways.
-//
-// The simplest option is to put them in assets/vendor and
-// import them using relative paths:
-//
-//     import "../vendor/some-package.js"
-//
-// Alternatively, you can `npm install some-package --prefix assets` and import
-// them using a path starting with the package name:
-//
-//     import "some-package"
-//
-
 import "phoenix_html"
-import {Socket} from "phoenix"
+import { Socket } from "phoenix"
-import {LiveSocket} from "phoenix_live_view"
+import { LiveSocket } from "phoenix_live_view"
 import topbar from "../vendor/topbar"
 import Alpine from "alpinejs"
+import { Terminal } from "xterm"
+import { FitAddon } from "@xterm/addon-fit"
 
-Alpine.start()
+let Hooks = {}
-window.Alpine = Alpine
+
+// TODO: Move this code and xterm into a separate generated file, and load that file only when needed
+Hooks.Terminal = {
+  mounted() {
+    const term = new Terminal({
+      fontFamily: '"Courier New", "DejaVu Sans Mono", "Everson Mono", monospace',
+      fontSize: 13,
+      convertEol: true,
+      theme: {
+        background: "#24273a",
+        foreground: "#cad3f5",
+        cursor: "#f4dbd6",
+        black: "#494D64",
+        red: "#ed8796",
+        green: "#a6da95",
+        yellow: "#eed49f",
+        blue: "#8aadf4",
+        magenta: "#f5bde6",
+        cyan: "#8bd5ca",
+        white: "#b8c0e0",
+      }
+    })
+
+    const fitAddon = new FitAddon()
+    const resizeObserver = new ResizeObserver(() => fitAddon.fit())
+
+    term.loadAddon(fitAddon)
+    term.open(this.el)
+    term.onData(data => this.pushEventTo(this.el, "data_event", data))
+    term.onResize(resize => this.pushEventTo(this.el, "resize_event", resize))
+
+    this.handleEvent("data", payload => term.write(payload.data || ""))
+
+    fitAddon.fit()
+    resizeObserver.observe(this.el)
+  }
+}
 
 let csrfToken = document.querySelector("meta[name='csrf-token']").getAttribute("content")
 let liveSocket = new LiveSocket("/live", Socket, {
-  params: {_csrf_token: csrfToken},
+  params: { _csrf_token: csrfToken },
   dom: {
     onBeforeElUpdated(from, to) {
       if (from._x_dataStack) {
         window.Alpine.clone(from, to)
       }
     }
-  }
+  },
+  hooks: Hooks,
 })
 
 // Show progress bar on live navigation and form submits
-topbar.config({barColors: {0: "#29d"}, shadowColor: "rgba(0, 0, 0, .3)"})
+topbar.config({ barColors: { 0: "#29d" }, shaDowColor: "rgba(0, 0, 0, .3)" })
 window.addEventListener("phx:page-loading-start", _info => topbar.show(300))
 window.addEventListener("phx:page-loading-stop", _info => topbar.hide())
 
@@ -50,3 +76,5 @@ liveSocket.connect()
 // >> liveSocket.disableLatencySim()
 window.liveSocket = liveSocket
 
+Alpine.start()
+window.Alpine = Alpine

app/assets/package-lock.json

@@ -5,7 +5,9 @@
   "packages": {
     "": {
       "dependencies": {
-        "alpinejs": "^3.13.3"
+        "@xterm/addon-fit": "^0.9.0-beta.1",
+        "alpinejs": "^3.13.3",
+        "xterm": "^5.3.0"
       }
     },
     "node_modules/@vue/reactivity": {
@@ -21,6 +23,14 @@
       "resolved": "https://registry.npmjs.org/@vue/shared/-/shared-3.1.5.tgz",
       "integrity": "sha512-oJ4F3TnvpXaQwZJNF3ZK+kLPHKarDmJjJ6jyzVNDKH9md1dptjC7lWR//jrGuLdek/U6iltWxqAnYOu8gCiOvA=="
     },
+    "node_modules/@xterm/addon-fit": {
+      "version": "0.9.0-beta.1",
+      "resolved": "https://registry.npmjs.org/@xterm/addon-fit/-/addon-fit-0.9.0-beta.1.tgz",
+      "integrity": "sha512-HmGRUMMamUpQYuQBF2VP1LJ0xzqF85LMFfpaNu84t1Tsrl1lPKJWtqX9FDZ22Rf5q6bnKdbj44TRVAUHgDRbLA==",
+      "peerDependencies": {
+        "xterm": "^5.0.0"
+      }
+    },
     "node_modules/alpinejs": {
       "version": "3.13.3",
       "resolved": "https://registry.npmjs.org/alpinejs/-/alpinejs-3.13.3.tgz",
@@ -28,6 +38,11 @@
       "dependencies": {
         "@vue/reactivity": "~3.1.1"
       }
+    },
+    "node_modules/xterm": {
+      "version": "5.3.0",
+      "resolved": "https://registry.npmjs.org/xterm/-/xterm-5.3.0.tgz",
+      "integrity": "sha512-8QqjlekLUFTrU6x7xck1MsPzPA571K5zNqWm0M0oroYEWVOptZ0+ubQSkQ3uxIEhcIHRujJy6emDWX4A7qyFzg=="
     }
   }
 }

app/assets/package.json

@@ -1,5 +1,7 @@
 {
   "dependencies": {
-    "alpinejs": "^3.13.3"
+    "@xterm/addon-fit": "^0.9.0-beta.1",
+    "alpinejs": "^3.13.3",
+    "xterm": "^5.3.0"
   }
 }

app/lib/prymn/agents.ex

@@ -131,6 +131,16 @@ defmodule Prymn.Agents do
   def sys_update(%Agent{} = agent, request) when is_map(request),
     do: sys_update(agent, struct(SysUpdateRequest, request))
 
+  def terminal(%Agent{} = agent) do
+    # TODO: Find a better solve for bi-directional GRPC stream
+    with {:ok, channel} <- get_channel(agent),
+         stream <- Stub.terminal(channel) do
+      stream
+    else
+      {:error, error} -> {:error, error}
+    end
+  end
+
   defp get_channel(%Agent{} = agent) do
     case start_connection(agent.host_address) do
       {:ok, pid} -> {:ok, Connection.get_channel(pid)}

app/lib/prymn/application.ex

@@ -15,6 +15,7 @@ defmodule Prymn.Application do
       {Finch, name: Prymn.Finch},
       {Oban, Application.fetch_env!(:prymn, Oban)},
       Prymn.Agents.Supervisor,
+      {Task.Supervisor, name: Prymn.TaskSupervisor},
       PrymnWeb.Endpoint
     ]
 

app/lib/prymn_web/components/system_info.ex

@@ -3,6 +3,7 @@ defmodule PrymnWeb.SystemInfo do
 
   require Logger
   alias Phoenix.LiveView.AsyncResult
+  alias PrymnProto.Prymn.SysInfoResponse
 
   @impl true
   def update(assigns, socket) do
@@ -59,7 +60,7 @@ defmodule PrymnWeb.SystemInfo do
     """
   end
 
-  def handle_async(:get_sys_info, {:ok, {:ok, sys_info}}, socket) do
+  def handle_async(:get_sys_info, {:ok, %SysInfoResponse{} = sys_info}, socket) do
     %{sys_info: sys_info_result, agent: agent} = socket.assigns
 
     {:noreply,

app/lib/prymn_web/components/terminal.ex

@@ -0,0 +1,120 @@
+defmodule PrymnWeb.Terminal do
+  use PrymnWeb, :live_component
+
+  alias PrymnProto.Prymn.TerminalRequest
+
+  @impl true
+  def mount(socket) do
+    {:ok, assign(socket, :open, false)}
+  end
+
+  @impl true
+  def update(assigns, socket) do
+    socket =
+      if assigns[:data],
+        do: push_event(socket, "data", %{"data" => assigns[:data]}),
+        else: socket
+
+    {:ok, assign(socket, assigns)}
+  end
+
+  @impl true
+  def render(assigns) do
+    ~H"""
+    <div>
+      <PrymnWeb.Button.primary
+        :if={not @open}
+        type="button"
+        phx-target={@myself}
+        phx-click="open_terminal"
+      >
+        Open Terminal
+      </PrymnWeb.Button.primary>
+      <PrymnWeb.Button.primary
+        :if={@open}
+        type="button"
+        phx-target={@myself}
+        phx-click="close_terminal"
+      >
+        Close Terminal
+      </PrymnWeb.Button.primary>
+      <div :if={@open} class="mt-2 bg-black p-2">
+        <div phx-hook="Terminal" id="terminal" />
+      </div>
+    </div>
+    """
+  end
+
+  @impl true
+  def handle_event("open_terminal", _params, socket) do
+    agent = Prymn.Agents.from_server(socket.assigns.server)
+    pid = self()
+
+    Task.Supervisor.start_child(Prymn.TaskSupervisor, fn ->
+      # FIXME: Have to wrap this in a Task because gun sends unsolicited messages
+      # to calling process
+      stream = Prymn.Agents.terminal(agent)
+
+      {:ok, mux_pid} =
+        Task.Supervisor.start_child(Prymn.TaskSupervisor, fn -> receive_loop(stream) end)
+
+      send_update(pid, PrymnWeb.Terminal, id: "terminal", mux_pid: mux_pid, open: true)
+
+      case GRPC.Stub.recv(stream, timeout: :infinity) do
+        {:ok, stream} ->
+          Enum.map(stream, fn
+            {:ok, %{output: data}} ->
+              send(mux_pid, :data)
+              send_update(pid, PrymnWeb.Terminal, id: "terminal", data: data)
+
+            {:error, _err} ->
+              send_update(pid, PrymnWeb.Terminal, id: "terminal", open: false)
+          end)
+
+        {:error, error} ->
+          dbg(error)
+      end
+    end)
+
+    {:noreply, socket}
+  end
+
+  def handle_event("close_terminal", _params, socket) do
+    send(socket.assigns.mux_pid, :close)
+    {:noreply, assign(socket, :open, false)}
+  end
+
+  def handle_event("data_event", data, socket) when is_binary(data) do
+    send(socket.assigns.mux_pid, {:data_event, data})
+    {:noreply, socket}
+  end
+
+  def handle_event("resize_event", %{"cols" => cols, "rows" => rows}, socket) do
+    send(socket.assigns.mux_pid, {:resize_event, rows, cols})
+    {:noreply, socket}
+  end
+
+  defp receive_loop(stream) do
+    receive do
+      {:data_event, data} ->
+        GRPC.Stub.send_request(stream, %TerminalRequest{input: data})
+        receive_loop(stream)
+
+      {:resize_event, rows, cols} ->
+        GRPC.Stub.send_request(stream, %TerminalRequest{
+          resize: %TerminalRequest.Resize{rows: rows, cols: cols}
+        })
+
+        receive_loop(stream)
+
+      :data ->
+        receive_loop(stream)
+
+      :close ->
+        GRPC.Stub.send_request(stream, %TerminalRequest{input: ""}, end_stream: true)
+    after
+      120_000 ->
+        GRPC.Stub.send_request(stream, %TerminalRequest{input: ""}, end_stream: true)
+    end
+  end
+end

app/lib/prymn_web/live/server_live/show.ex

@@ -71,20 +71,18 @@ defmodule PrymnWeb.ServerLive.Show do
           </button>
         </div>
       </div>
-      <div :if={@server.status == :registered} class="my-10">
+      <form phx-change="change_dry_run">
+        <.input type="checkbox" name="dry_run" value={@dry_run} label="Enable dry-run operations" />
+      </form>
+      <div :if={@server.status == :registered} class="my-10 space-y-5 divide-y">
         <.live_component
           id={"system_info-#{@server.name}"}
           module={PrymnWeb.SystemInfo}
           agent={assigns[:agent]}
         />
-        <section class="mt-4">
+        <section>
-          <form phx-change="change_dry_run">
+          <h2 class="my-5 text-xl">System</h2>
-            <.input type="checkbox" name="dry_run" value={@dry_run} label="Enable dry-run operations" />
+          <p>
-          </form>
-        </section>
-        <section class="mt-4">
-          <h2 class="border-b border-solid border-gray-500 pb-1 text-2xl font-medium">System</h2>
-          <p class="mt-4">
             Updates: <%= 0 %> pending updates.
             <Button.primary type="button" class="ml-4" phx-click="system_update">
               Update now
@@ -94,32 +92,11 @@ defmodule PrymnWeb.ServerLive.Show do
             </p>
           </p>
         </section>
-        <section class="mt-4">
+        <section>
-          <h2 class="border-b border-solid border-gray-500 pb-1 text-2xl font-medium">
+          <h2 class="my-5 text-xl">
-            Backups
+            Terminal
           </h2>
-          <.table id="backups" rows={[%{date: "2023-10-11"}, %{date: "2023-10-10"}]}>
+          <.live_component id="terminal" module={PrymnWeb.Terminal} server={@server} />
-            <:col :let={backup} label="Date"><%= backup.date %></:col>
-            <:action>
-              <Button.primary>Restore</Button.primary>
-            </:action>
-          </.table>
-        </section>
-        <section class="mt-4">
-          <h2 class="border-b border-solid border-gray-500 pb-1 text-2xl font-medium">
-            Manage Services
-          </h2>
-          <.table
-            id="services"
-            rows={[%{name: "mariadb", status: "Active"}, %{name: "php8.0", status: "Disabled"}]}
-          >
-            <:col :let={service} label="Service"><%= service.name %></:col>
-            <:col :let={service} label="Status"><%= service.status %></:col>
-            <:action>
-              <Button.primary>Activate</Button.primary>
-              <Button.secondary>Deactivate</Button.secondary>
-            </:action>
-          </.table>
         </section>
       </div>
       <.back navigate={~p"/servers"}>Back to servers</.back>

proto/agent.proto

@@ -69,9 +69,24 @@ message SysUpdateResponse {
     int32 progress = 2;
 }
 
+message TerminalRequest {
+    message Resize {
+        uint32 rows = 1;
+        uint32 cols = 2;
+    }
+
+    bytes input = 1;
+    optional Resize resize = 2;
+}
+
+message TerminalResponse {
+    bytes output = 1;
+}
+
 service Agent {
     rpc Health(google.protobuf.Empty) returns (stream HealthResponse);
     rpc Exec(ExecRequest) returns (stream ExecResponse);
+    rpc Terminal(stream TerminalRequest) returns (stream TerminalResponse);
     rpc GetSysInfo(google.protobuf.Empty) returns (SysInfoResponse);
     rpc SysUpdate(SysUpdateRequest) returns (stream SysUpdateResponse);
 }