Make client-socket into a feature

So we can use it on F37+ builds.

Cargo.toml

@@ -123,6 +123,8 @@ lto = "thin"
 # Note: If you add a feature here, you also probably want to update utils.rs:get_features()
 fedora-integration = []
 rhsm = ["libdnf-sys/rhsm"]
+# Enable hard requirement on `rpm-ostreed.socket`; requires https://bugzilla.redhat.com/show_bug.cgi?id=2110012
+client-socket = []
 bin-unit-tests = []
 # ASAN+UBSAN
 sanitizers = []

rust/src/client.rs

@@ -154,6 +154,26 @@ pub(crate) fn client_handle_fd_argument(
     }
 }
 
+/// Connect to the client socket and ensure the daemon is initialized;
+/// this avoids DBus and ensures that we get any early startup errors
+/// returned cleanly.
+#[cfg(feature = "client-socket")]
+fn start_daemon_via_socket() -> Result<()> {
+    let address = "/run/rpm-ostree/client.sock";
+    tracing::debug!("Starting daemon via {address}");
+    let s = std::os::unix::net::UnixStream::connect(address)
+        .with_context(|| anyhow!("Failed to connect to {}", address))?;
+    let mut s = std::io::BufReader::new(s);
+    let mut r = String::new();
+    s.read_to_string(&mut r)
+        .context("Reading from client socket")?;
+    if r.is_empty() {
+        Ok(())
+    } else {
+        Err(anyhow!("{r}").into())
+    }
+}
+
 /// Explicitly ensure the daemon is started via systemd, if possible.
 ///
 /// This works around bugs from DBus activation, see
@@ -164,12 +184,14 @@ pub(crate) fn client_handle_fd_argument(
 /// to systemd directly and use its client tools to scrape errors.
 ///
 /// What we really should do probably is use native socket activation.
-pub(crate) fn client_start_daemon() -> CxxResult<()> {
+#[cfg(not(feature = "client-socket"))]
+fn start_daemon_via_systemctl() -> Result<()> {
     let service = "rpm-ostreed.service";
     // Assume non-root can't use systemd right now.
     if rustix::process::getuid().as_raw() != 0 {
         return Ok(());
     }
+
     // Unfortunately, RHEL8 systemd will count "systemctl start"
     // invocations against the restart limit, so query the status
     // first.
@@ -196,6 +218,18 @@ pub(crate) fn client_start_daemon() -> CxxResult<()> {
     Ok(())
 }
 
+pub(crate) fn client_start_daemon() -> CxxResult<()> {
+    // systemctl and socket paths only work for root right now; in the future
+    // the socket may be opened up.
+    if rustix::process::getuid().as_raw() != 0 {
+        return Ok(());
+    }
+    #[cfg(feature = "client-socket")]
+    return start_daemon_via_socket().map_err(Into::into);
+    #[cfg(not(feature = "client-socket"))]
+    return start_daemon_via_systemctl().map_err(Into::into);
+}
+
 /// Convert the GVariant parameters from the DownloadProgress DBus API to a human-readable English string.
 pub(crate) fn client_render_download_progress(progress: &crate::ffi::GVariant) -> String {
     let progress = progress

rust/src/daemon.rs

@@ -135,25 +135,6 @@ fn deployment_populate_variant_origin(
     Ok(())
 }
 
-/// Connect to the client socket and ensure the daemon is initialized;
-/// this avoids DBus and ensures that we get any early startup errors
-/// returned cleanly.
-pub(crate) fn start_daemon_via_socket() -> CxxResult<()> {
-    let address = "/run/rpm-ostree/client.sock";
-    tracing::debug!("Starting daemon via {address}");
-    let s = std::os::unix::net::UnixStream::connect(address)
-        .with_context(|| anyhow!("Failed to connect to {}", address))?;
-    let mut s = std::io::BufReader::new(s);
-    let mut r = String::new();
-    s.read_to_string(&mut r)
-        .context("Reading from client socket")?;
-    if r.is_empty() {
-        Ok(())
-    } else {
-        Err(anyhow!("{r}").into())
-    }
-}
-
 async fn send_ok_result_to_client(_client: UnixStream) {
     // On success we close the stream without writing anything,
     // which acknowledges successful startup to the client.
@@ -229,7 +210,10 @@ pub(crate) fn daemon_main(debug: bool) -> Result<()> {
             // directly propagate the error back to our exit code.
             init_res?;
             tracing::debug!("Initializing directly (not socket activated)");
-            StdUnixListener::bind("/run/rpm-ostree/client.sock")?
+            cfg!(feature = "client-socket")
+                .then(|| StdUnixListener::bind("/run/rpm-ostree/client.sock"))
+                .transpose()
+                .context("Binding to socket")?
         }
         Some(fd) => {
             if fds.next().is_some() {
@@ -239,7 +223,7 @@ pub(crate) fn daemon_main(debug: bool) -> Result<()> {
             let listener = unsafe { StdUnixListener::from_raw_fd(fd) };
 
             match init_res {
-                Ok(_) => listener,
+                Ok(_) => Some(listener),
                 Err(e) => {
                     let err_copy = anyhow!("{e}");
                     tracing::debug!("Reporting initialization error: {e}");
@@ -257,16 +241,18 @@ pub(crate) fn daemon_main(debug: bool) -> Result<()> {
         }
     };
 
-    let (shutdown_send, shutdown_recv) = tokio::sync::oneshot::channel();
-    (*SHUTDOWN_SIGNAL).lock().unwrap().replace(shutdown_send);
+    if let Some(listener) = listener {
+        let (shutdown_send, shutdown_recv) = tokio::sync::oneshot::channel();
+        (*SHUTDOWN_SIGNAL).lock().unwrap().replace(shutdown_send);
 
-    let listener = UnixListener::from_std(listener)?;
+        let listener = UnixListener::from_std(listener)?;
 
-    // On success, we spawn a helper task that just responds with
-    // sucess to clients that connect via the socket.  In the future,
-    // perhaps we'll expose an API here.
-    tracing::debug!("Spawning acknowledgement task");
-    tokio::task::spawn(async { process_clients_with_ok(listener, shutdown_recv).await });
+        // On success, we spawn a helper task that just responds with
+        // sucess to clients that connect via the socket.  In the future,
+        // perhaps we'll expose an API here.
+        tracing::debug!("Spawning acknowledgement task");
+        tokio::task::spawn(async { process_clients_with_ok(listener, shutdown_recv).await });
+    }
 
     tracing::debug!("Entering daemon mainloop");
     // And now, enter the main loop.

rust/src/lib.rs

@@ -300,7 +300,6 @@ pub mod ffi {
     // daemon.rs
     extern "Rust" {
         fn daemon_main(debug: bool) -> Result<()>;
-        fn start_daemon_via_socket() -> Result<()>;
         fn daemon_terminate();
         fn daemon_sanitycheck_environment(sysroot: &OstreeSysroot) -> Result<()>;
         fn deployment_generate_id(deployment: &OstreeDeployment) -> String;

src/app/libmain.cxx

@@ -281,8 +281,6 @@ rpmostree_option_context_parse (GOptionContext *context, const GOptionEntry *mai
             return rpmostreecxx::client_throw_non_ostree_host_error (error);
         }
 
-      CXX_TRY (rpmostreecxx::start_daemon_via_socket (), error);
-
       /* root never needs to auth */
       if (getuid () != 0)
         /* ignore errors; we print out a warning if we fail to spawn pkttyagent */