* Change behavior of namespace change - set the namespace only in the…

… packet sniffing, in a new thread so command socket will listen on the original network namespace

*formatting

CHANGELOG.md

@@ -1,4 +1,7 @@
 ## [Unreleased]
+## 2.0.0-alpha-3 - 1/5/2022
+### Changed
+* Change behavior of namespace change - set the namespace only in the packet sniffing, in a new thread so "command" socket will listen on the original network namespace
 ## 2.0.0-alpha-2 - 30/4/2022
 ### Fixed
 * Fixed obtaining namespace & setting it using container id (seems to be a bug in new containerd-client version?)

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "mirrord-agent"
-version = "2.0.0-alpha-2"
+version = "2.0.0-alpha-3"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
@@ -14,7 +14,6 @@ pcap = { git = "https://github.com/aviramha/pcap.git", branch="make_codec_public
 pnet = "0.29.0"
 nix = "0.23.1"
 anyhow = "1"
-base64 = "0.13"
 clap = { version = "3.1.2", features = ["derive"] }
 mirrord-protocol = "0.2"
 env_logger = "0.9"

src/main.rs

@@ -1,27 +1,28 @@
 use anyhow::Result;
 
 use futures::SinkExt;
-use tokio::{select, task};
+use tokio::{
+    net::{TcpListener, TcpStream},
+    select,
+    sync::mpsc::{self},
+};
 use tokio_stream::StreamExt;
 use tracing::{debug, error, info};
 
-use std::borrow::Borrow;
-use std::collections::HashSet;
-use std::hash::{Hash, Hasher};
-// use mirrord_protocol::{MirrordCodec, MirrordMessage};
-use std::net::{Ipv4Addr, SocketAddrV4};
-use tokio::net::{TcpListener, TcpStream};
-
-use tokio::sync::mpsc::{self};
+use mirrord_protocol::{ClientMessage, ConnectionID, DaemonCodec, DaemonMessage, Port};
+use std::{
+    borrow::Borrow,
+    collections::HashSet,
+    hash::{Hash, Hasher},
+    net::{Ipv4Addr, SocketAddrV4},
+};
 
 mod cli;
 mod runtime;
 mod sniffer;
 mod util;
 
 use cli::parse_args;
-use mirrord_protocol::{ClientMessage, ConnectionID, DaemonCodec, DaemonMessage, Port};
-use runtime::{get_container_namespace, set_namespace};
 use sniffer::{packet_worker, SnifferCommand, SnifferOutput};
 use util::{IndexAllocator, Subscriptions};
 
@@ -140,11 +141,6 @@ async fn peer_handler(
 async fn start() -> Result<()> {
     let args = parse_args();
     debug!("mirrord-agent starting with args {:?}", args);
-    if let Some(container_id) = args.container_id {
-        let namespace = get_container_namespace(container_id).await?;
-        debug!("Found namespace to attach to {:?}", &namespace);
-        set_namespace(&namespace)?;
-    }
 
     let listener = TcpListener::bind(SocketAddrV4::new(
         Ipv4Addr::new(0, 0, 0, 0),
@@ -156,10 +152,12 @@ async fn start() -> Result<()> {
     let (peers_tx, mut peers_rx) = mpsc::channel::<PeerMessage>(1000);
     let (packet_sniffer_tx, mut packet_sniffer_rx) = mpsc::channel::<SnifferOutput>(1000);
     let (packet_command_tx, packet_command_rx) = mpsc::channel::<SnifferCommand>(1000);
-    let packet_task = task::spawn(packet_worker(
+    // We use tokio spawn so it'll create another thread.
+    let packet_task = tokio::spawn(packet_worker(
         packet_sniffer_tx,
         packet_command_rx,
         args.interface.clone(),
+        args.container_id.clone(),
     ));
     loop {
         select! {

src/sniffer.rs

@@ -18,7 +18,10 @@ use std::net::{IpAddr, Ipv4Addr};
 use tokio::select;
 use tracing::{debug, error};
 
-use crate::util::IndexAllocator;
+use crate::{
+    runtime::{get_container_namespace, set_namespace},
+    util::IndexAllocator,
+};
 use mirrord_protocol::{NewTCPConnection, TCPClose, TCPData};
 
 const DUMMY_BPF: &str =
@@ -228,7 +231,14 @@ pub async fn packet_worker(
     tx: Sender<SnifferOutput>,
     mut rx: Receiver<SnifferCommand>,
     interface: String,
+    container_id: Option<String>,
 ) -> Result<()> {
+    debug!("setting namespace");
+    if let Some(container_id) = container_id {
+        let namespace = get_container_namespace(container_id).await?;
+        debug!("Found namespace to attach to {:?}", &namespace);
+        set_namespace(&namespace)?;
+    }
     debug!("preparing sniffer");
     let sniffer = prepare_sniffer(interface)?;
     debug!("done prepare sniffer");