vmm: http: graceful shutdown of the http api thread

This commit ensures that the HttpApi thread flushes all the responses
before the application shuts down. Without this step, in case of a
VmmShutdown request the application might terminate before the
thread sends a response.

Fixes: #6247

Signed-off-by: Alexandru Matei <alexandru.matei@uipath.com>

src/main.rs

@@ -20,6 +20,7 @@ use std::sync::{Arc, Mutex};
 use thiserror::Error;
 #[cfg(feature = "dbus_api")]
 use vmm::api::dbus::{dbus_api_graceful_shutdown, DBusApiOptions};
+use vmm::api::http::http_api_graceful_shutdown;
 use vmm::api::ApiAction;
 use vmm::config;
 use vmm_sys_util::eventfd::EventFd;
@@ -82,6 +83,8 @@ enum Error {
     LogFileCreation(std::io::Error),
     #[error("Error setting up logger: {0}")]
     LoggerSetup(log::SetLoggerError),
+    #[error("Failed to gracefully shutdown http api: {0}")]
+    HttpApiShutdown(#[source] vmm::Error),
 }
 
 struct Logger {
@@ -760,6 +763,10 @@ fn start_vmm(cmd_arguments: ArgMatches) -> Result<Option<String>, Error> {
         .map_err(Error::ThreadJoin)?
         .map_err(Error::VmmThread)?;
 
+    if let Some(api_handle) = vmm_thread_handle.http_api_handle {
+        http_api_graceful_shutdown(api_handle).map_err(Error::HttpApiShutdown)?
+    }
+
     #[cfg(feature = "dbus_api")]
     if let Some(chs) = vmm_thread_handle.dbus_shutdown_chs {
         dbus_api_graceful_shutdown(chs);