1
0
forked from wrenn/wrenn

feat: rewrite envd guest agent in Rust (envd-rs)

Complete Rust rewrite of the Go envd guest daemon that runs as PID 1
inside Firecracker microVMs. Feature-complete across all 8 phases:

- Health, metrics, and env var endpoints
- Crypto (SHA-256/512, HMAC), auth (secure token, signing), init/snapshot
- Connect RPC via connectrpc + buffa (process + filesystem services)
- File transfer (GET/POST /files) with gzip, multipart, chown, ENOSPC
- Port subsystem (/proc/net/tcp scanner, socat forwarder)
- Cgroup2 manager with noop fallback
- Snapshot/restore lifecycle (conntracker, port subsystem stop/restart)
- SIGTERM graceful shutdown, --cmd initial process spawn
- MMDS metadata polling for Firecracker mode

42 source files, ~4200 LOC, 4.1MB stripped release binary.
Makefile updated: build-envd now targets Rust (musl static),
build-envd-go preserved for Go builds.
This commit is contained in:
2026-05-03 02:47:15 +06:00
parent 3deecbff89
commit 0b53d34417
54 changed files with 7089 additions and 17 deletions

View File

@ -0,0 +1,438 @@
use std::collections::HashMap;
use std::pin::Pin;
use std::sync::Arc;
use connectrpc::{ConnectError, Context, ErrorCode};
use dashmap::DashMap;
use futures::Stream;
use crate::permissions::path::expand_and_resolve;
use crate::permissions::user::lookup_user;
use crate::rpc::pb::process::*;
use crate::rpc::process_handler::{self, DataEvent, ProcessHandle};
use crate::state::AppState;
pub struct ProcessServiceImpl {
state: Arc<AppState>,
processes: DashMap<u32, Arc<ProcessHandle>>,
}
impl ProcessServiceImpl {
pub fn new(state: Arc<AppState>) -> Self {
Self {
state,
processes: DashMap::new(),
}
}
fn get_process_by_selector(
&self,
selector: &ProcessSelectorView,
) -> Result<Arc<ProcessHandle>, ConnectError> {
match &selector.selector {
Some(process_selector::SelectorView::Pid(pid)) => {
let pid_val = *pid;
self.processes
.get(&pid_val)
.map(|entry| Arc::clone(entry.value()))
.ok_or_else(|| {
ConnectError::new(
ErrorCode::NotFound,
format!("process with pid {pid_val} not found"),
)
})
}
Some(process_selector::SelectorView::Tag(tag)) => {
let tag_str: &str = tag;
for entry in self.processes.iter() {
if let Some(ref t) = entry.value().tag {
if t == tag_str {
return Ok(Arc::clone(entry.value()));
}
}
}
Err(ConnectError::new(
ErrorCode::NotFound,
format!("process with tag {tag_str} not found"),
))
}
None => Err(ConnectError::new(
ErrorCode::InvalidArgument,
"process selector required",
)),
}
}
fn spawn_from_request(
&self,
request: &StartRequestView<'_>,
) -> Result<Arc<ProcessHandle>, ConnectError> {
let proc_config = request.process.as_option().ok_or_else(|| {
ConnectError::new(ErrorCode::InvalidArgument, "process config required")
})?;
let username = self.state.defaults.user.clone();
let user =
lookup_user(&username).map_err(|e| ConnectError::new(ErrorCode::Internal, e))?;
let cmd: &str = proc_config.cmd;
let args: Vec<String> = proc_config.args.iter().map(|s| s.to_string()).collect();
let envs: HashMap<String, String> = proc_config
.envs
.iter()
.map(|(k, v)| (k.to_string(), v.to_string()))
.collect();
let home_dir = format!("/home/{}", user.name);
let cwd_str: &str = proc_config.cwd.unwrap_or("");
let cwd = expand_and_resolve(cwd_str, &home_dir, self.state.defaults.workdir.as_deref())
.map_err(|e| ConnectError::new(ErrorCode::InvalidArgument, e))?;
let effective_cwd = if cwd.is_empty() { "/" } else { &cwd };
if let Err(_) = std::fs::metadata(effective_cwd) {
return Err(ConnectError::new(
ErrorCode::InvalidArgument,
format!("cwd '{effective_cwd}' does not exist"),
));
}
let pty_opts = request.pty.as_option().and_then(|pty| {
pty.size
.as_option()
.map(|sz| (sz.cols as u16, sz.rows as u16))
});
let enable_stdin = request.stdin.unwrap_or(true);
let tag = request.tag.map(|s| s.to_string());
let handle = process_handler::spawn_process(
cmd,
&args,
&envs,
effective_cwd,
pty_opts,
enable_stdin,
tag,
&user,
&self.state.defaults.env_vars,
)?;
self.processes.insert(handle.pid, Arc::clone(&handle));
let processes = self.processes.clone();
let pid = handle.pid;
let mut end_rx = handle.subscribe_end();
tokio::spawn(async move {
let _ = end_rx.recv().await;
processes.remove(&pid);
});
Ok(handle)
}
}
impl Process for ProcessServiceImpl {
async fn list(
&self,
ctx: Context,
_request: buffa::view::OwnedView<ListRequestView<'static>>,
) -> Result<(ListResponse, Context), ConnectError> {
let processes: Vec<ProcessInfo> = self
.processes
.iter()
.map(|entry| {
let h = entry.value();
ProcessInfo {
config: buffa::MessageField::some(h.config.clone()),
pid: h.pid,
tag: h.tag.clone(),
..Default::default()
}
})
.collect();
Ok((
ListResponse {
processes,
..Default::default()
},
ctx,
))
}
async fn start(
&self,
ctx: Context,
request: buffa::view::OwnedView<StartRequestView<'static>>,
) -> Result<
(
Pin<Box<dyn Stream<Item = Result<StartResponse, ConnectError>> + Send>>,
Context,
),
ConnectError,
> {
let handle = self.spawn_from_request(&request)?;
let pid = handle.pid;
let mut data_rx = handle.subscribe_data();
let mut end_rx = handle.subscribe_end();
let stream = async_stream::stream! {
yield Ok(make_start_response(pid));
loop {
match data_rx.recv().await {
Ok(ev) => yield Ok(make_data_start_response(ev)),
Err(tokio::sync::broadcast::error::RecvError::Lagged(_)) => continue,
Err(tokio::sync::broadcast::error::RecvError::Closed) => break,
}
}
if let Ok(end) = end_rx.recv().await {
yield Ok(make_end_start_response(end));
}
};
Ok((Box::pin(stream), ctx))
}
async fn connect(
&self,
ctx: Context,
request: buffa::view::OwnedView<ConnectRequestView<'static>>,
) -> Result<
(
Pin<Box<dyn Stream<Item = Result<ConnectResponse, ConnectError>> + Send>>,
Context,
),
ConnectError,
> {
let selector = request.process.as_option().ok_or_else(|| {
ConnectError::new(ErrorCode::InvalidArgument, "process selector required")
})?;
let handle = self.get_process_by_selector(selector)?;
let pid = handle.pid;
let mut data_rx = handle.subscribe_data();
let mut end_rx = handle.subscribe_end();
let stream = async_stream::stream! {
yield Ok(ConnectResponse {
event: buffa::MessageField::some(ProcessEvent {
event: Some(process_event::Event::Start(Box::new(
process_event::StartEvent { pid, ..Default::default() },
))),
..Default::default()
}),
..Default::default()
});
loop {
match data_rx.recv().await {
Ok(ev) => {
yield Ok(ConnectResponse {
event: buffa::MessageField::some(make_data_event(ev)),
..Default::default()
});
}
Err(tokio::sync::broadcast::error::RecvError::Lagged(_)) => continue,
Err(tokio::sync::broadcast::error::RecvError::Closed) => break,
}
}
if let Ok(end) = end_rx.recv().await {
yield Ok(ConnectResponse {
event: buffa::MessageField::some(make_end_event(end)),
..Default::default()
});
}
};
Ok((Box::pin(stream), ctx))
}
async fn update(
&self,
ctx: Context,
request: buffa::view::OwnedView<UpdateRequestView<'static>>,
) -> Result<(UpdateResponse, Context), ConnectError> {
let selector = request.process.as_option().ok_or_else(|| {
ConnectError::new(ErrorCode::InvalidArgument, "process selector required")
})?;
let handle = self.get_process_by_selector(selector)?;
if let Some(pty) = request.pty.as_option() {
if let Some(size) = pty.size.as_option() {
handle.resize_pty(size.cols as u16, size.rows as u16)?;
}
}
Ok((UpdateResponse { ..Default::default() }, ctx))
}
async fn stream_input(
&self,
ctx: Context,
mut requests: Pin<
Box<
dyn Stream<
Item = Result<
buffa::view::OwnedView<StreamInputRequestView<'static>>,
ConnectError,
>,
> + Send,
>,
>,
) -> Result<(StreamInputResponse, Context), ConnectError> {
use futures::StreamExt;
let mut handle: Option<Arc<ProcessHandle>> = None;
while let Some(result) = requests.next().await {
let req = result?;
match &req.event {
Some(stream_input_request::EventView::Start(start)) => {
if let Some(selector) = start.process.as_option() {
handle = Some(self.get_process_by_selector(selector)?);
}
}
Some(stream_input_request::EventView::Data(data)) => {
let h = handle.as_ref().ok_or_else(|| {
ConnectError::new(ErrorCode::FailedPrecondition, "no start event received")
})?;
if let Some(input) = data.input.as_option() {
write_input(h, input)?;
}
}
Some(stream_input_request::EventView::Keepalive(_)) => {}
None => {}
}
}
Ok((StreamInputResponse { ..Default::default() }, ctx))
}
async fn send_input(
&self,
ctx: Context,
request: buffa::view::OwnedView<SendInputRequestView<'static>>,
) -> Result<(SendInputResponse, Context), ConnectError> {
let selector = request.process.as_option().ok_or_else(|| {
ConnectError::new(ErrorCode::InvalidArgument, "process selector required")
})?;
let handle = self.get_process_by_selector(selector)?;
if let Some(input) = request.input.as_option() {
write_input(&handle, input)?;
}
Ok((SendInputResponse { ..Default::default() }, ctx))
}
async fn send_signal(
&self,
ctx: Context,
request: buffa::view::OwnedView<SendSignalRequestView<'static>>,
) -> Result<(SendSignalResponse, Context), ConnectError> {
let selector = request.process.as_option().ok_or_else(|| {
ConnectError::new(ErrorCode::InvalidArgument, "process selector required")
})?;
let handle = self.get_process_by_selector(selector)?;
let sig = match request.signal.as_known() {
Some(Signal::SIGNAL_SIGKILL) => nix::sys::signal::Signal::SIGKILL,
Some(Signal::SIGNAL_SIGTERM) => nix::sys::signal::Signal::SIGTERM,
_ => {
return Err(ConnectError::new(
ErrorCode::InvalidArgument,
"invalid or unspecified signal",
))
}
};
handle.send_signal(sig)?;
Ok((SendSignalResponse { ..Default::default() }, ctx))
}
async fn close_stdin(
&self,
ctx: Context,
request: buffa::view::OwnedView<CloseStdinRequestView<'static>>,
) -> Result<(CloseStdinResponse, Context), ConnectError> {
let selector = request.process.as_option().ok_or_else(|| {
ConnectError::new(ErrorCode::InvalidArgument, "process selector required")
})?;
let handle = self.get_process_by_selector(selector)?;
handle.close_stdin()?;
Ok((CloseStdinResponse { ..Default::default() }, ctx))
}
}
fn write_input(handle: &ProcessHandle, input: &ProcessInputView) -> Result<(), ConnectError> {
match &input.input {
Some(process_input::InputView::Pty(d)) => handle.write_pty(d),
Some(process_input::InputView::Stdin(d)) => handle.write_stdin(d),
None => Ok(()),
}
}
fn make_start_response(pid: u32) -> StartResponse {
StartResponse {
event: buffa::MessageField::some(ProcessEvent {
event: Some(process_event::Event::Start(Box::new(
process_event::StartEvent {
pid,
..Default::default()
},
))),
..Default::default()
}),
..Default::default()
}
}
fn make_data_event(ev: DataEvent) -> ProcessEvent {
let output = match ev {
DataEvent::Stdout(d) => Some(process_event::data_event::Output::Stdout(d.into())),
DataEvent::Stderr(d) => Some(process_event::data_event::Output::Stderr(d.into())),
DataEvent::Pty(d) => Some(process_event::data_event::Output::Pty(d.into())),
};
ProcessEvent {
event: Some(process_event::Event::Data(Box::new(
process_event::DataEvent {
output,
..Default::default()
},
))),
..Default::default()
}
}
fn make_data_start_response(ev: DataEvent) -> StartResponse {
StartResponse {
event: buffa::MessageField::some(make_data_event(ev)),
..Default::default()
}
}
fn make_end_event(end: process_handler::EndEvent) -> ProcessEvent {
ProcessEvent {
event: Some(process_event::Event::End(Box::new(
process_event::EndEvent {
exit_code: end.exit_code,
exited: end.exited,
status: end.status,
error: end.error,
..Default::default()
},
))),
..Default::default()
}
}
fn make_end_start_response(end: process_handler::EndEvent) -> StartResponse {
StartResponse {
event: buffa::MessageField::some(make_end_event(end)),
..Default::default()
}
}