Spawn daemon in separate process (this should fail in CI)

.github/workflows/build.yaml

@@ -41,8 +41,8 @@ jobs:
 
       - name: Build package and create closure for ${{ matrix.systems.system }}
         run: |
-          nix build .# -L --fallback && \
-            nix-store --export $(nix-store -qR ./result) | xz -9 > "${{ env.ARCHIVE_NAME }}"
+          nix build .# -L --fallback
+          nix-store --export $(nix-store -qR ./result) | xz -9 > "${{ env.ARCHIVE_NAME }}"
 
       - name: Upload magic-nix-cache closure for ${{ matrix.systems.system }}
         uses: actions/upload-artifact@v3.1.2

magic-nix-cache/src/main.rs

@@ -26,6 +26,7 @@ use std::io::Write;
 use std::net::SocketAddr;
 use std::os::unix::fs::PermissionsExt;
 use std::path::{Path, PathBuf};
+use std::process::exit;
 use std::sync::Arc;
 
 use ::attic::nix_store::NixStore;
@@ -370,6 +371,21 @@ async fn main_cli() -> Result<()> {
 
     tracing::info!("Listening on {}", args.listen);
 
+    let server = axum::Server::bind(&args.listen)
+        .serve(app.into_make_service())
+        .with_graceful_shutdown(async move {
+            shutdown_receiver.await.ok();
+            tracing::info!("Shutting down");
+        });
+
+    // Spawn here so that post-startup tasks can proceed
+    tokio::spawn(async move {
+        if let Err(e) = server.await {
+            tracing::error!("failed to start up daemon: {e}");
+            exit(1);
+        }
+    });
+
     // Notify of startup via HTTP
     if let Some(startup_notification_url) = args.startup_notification_url {
         tracing::debug!("Startup notification via HTTP POST to {startup_notification_url}");
@@ -411,21 +427,11 @@ async fn main_cli() -> Result<()> {
         tracing::debug!("Created startup notification file at {startup_notification_file_path:?}");
     }
 
-    let ret = axum::Server::bind(&args.listen)
-        .serve(app.into_make_service())
-        .with_graceful_shutdown(async move {
-            shutdown_receiver.await.ok();
-            tracing::info!("Shutting down");
-        })
-        .await;
-
     // Notify diagnostics endpoint
     if let Some(diagnostic_endpoint) = diagnostic_endpoint {
         state.metrics.send(diagnostic_endpoint).await;
     }
 
-    ret?;
-
     Ok(())
 }