Kill intproxy on a bogus binary. (#2510)

* Kill intproxy on a bogus binary.

* expect

* changelog

* cr suggestions / kill before if / use start_kill

* fix macos

* clippy

changelog.d/2386.fixed.md

@@ -0,0 +1 @@
+Kill the intproxy child process when mirrord-cli execvp fails.

mirrord/cli/src/execution.rs

@@ -127,6 +127,8 @@ where
 }
 
 impl MirrordExecution {
+    /// Starts the internal proxy (`intproxy`), and mirrord-layer, even if a bogus binary
+    /// was passed by the user.
     #[tracing::instrument(level = "trace", skip_all)]
     pub(crate) async fn start<P>(
         config: &LayerConfig,
@@ -362,4 +364,13 @@ impl MirrordExecution {
             .map_err(CliError::InternalProxyWaitError)?;
         Ok(())
     }
+
+    /// Kills the child process, stopping the internal proxy, and completing the agent.
+    ///
+    /// Used when mirrord execution fails inside `execvp`.
+    pub async fn stop(self) {
+        let Self { mut child, .. } = self;
+
+        let _ = child.start_kill();
+    }
 }

mirrord/cli/src/main.rs

@@ -81,7 +81,7 @@ where
     #[cfg(target_os = "macos")]
     let (_did_sip_patch, binary) = match execution_info.patched_path {
         None => (false, args.binary.clone()),
-        Some(sip_result) => (true, sip_result),
+        Some(ref sip_result) => (true, sip_result.to_owned()),
     };
 
     #[cfg(not(target_os = "macos"))]
@@ -120,6 +120,10 @@ where
     let err = execvp(binary.clone(), binary_args.clone());
     error!("Couldn't execute {:?}", err);
     analytics.set_error(AnalyticsError::BinaryExecuteFailed);
+
+    // Kills the intproxy, freeing the agent.
+    execution_info.stop().await;
+
     #[cfg(all(target_os = "macos", target_arch = "aarch64"))]
     if let exec::Error::Errno(errno) = err {
         if Into::<i32>::into(errno) == 86 {
@@ -129,6 +133,7 @@ where
             }
         }
     }
+
     Err(CliError::BinaryExecuteFailed(binary, binary_args))
 }