fix(launcher): reuse MPC container across restarts to preserve logs (#3705)

Author: barakeinav1

crates/tee-launcher/assets/mpc-node-docker-compose.tee.template.yml

@@ -1,3 +1,5 @@
+name: mpc-node
+
 services:
   mpc-node:
     image: "{{IMAGE_NAME}}@{{MANIFEST_DIGEST}}"

crates/tee-launcher/assets/mpc-node-docker-compose.template.yml

@@ -1,3 +1,5 @@
+name: mpc-node
+
 services:
   mpc-node:
     image: "{{IMAGE_NAME}}@{{MANIFEST_DIGEST}}"

crates/tee-launcher/src/compose.rs

@@ -59,11 +59,10 @@ pub fn launch_mpc_container(
     let compose_file = render_compose_file(platform, port_mappings, image_name, manifest_digest)?;
     let compose_path = compose_file.path().display().to_string();
 
-    // Remove any existing container from a previous run (by name, independent of compose file)
-    let _ = Command::new("docker")
-        .args(["rm", "-f", MPC_CONTAINER_NAME])
-        .output();
-
+    // The compose file pins a stable top-level project `name`, so the
+    // container is reused across restarts rather than recreated, preserving its
+    // logs. Compose recreates it only when the rendered config (e.g. image
+    // digest) changes.
     let run_output = Command::new("docker")
         .args(["compose", "-f", &compose_path, "up", "-d"])
         .output()
@@ -265,4 +264,19 @@ mod tests {
         // then
         assert!(!rendered.contains("environment:"));
     }
+
+    #[test]
+    fn includes_stable_project_name() {
+        // given
+        let port_mappings = empty_port_mappings();
+        let digest = sample_digest();
+
+        // when
+        let rendered = render(Platform::Tee, &port_mappings, &digest);
+
+        // then — a stable top-level project name keeps Compose reusing the
+        // container across restarts instead of recreating it (which would wipe
+        // its logs)
+        assert!(rendered.contains("name: mpc-node"));
+    }
 }

docs/running-an-mpc-node-in-tdx-external-guide.md

@@ -966,6 +966,10 @@ Full flag reference and `.env` field-by-field documentation:
 Dstack provides a dedicated web page to view CVM information, including links to the Docker logs.
 More details can be found in [Phala's guide](https://github.com/Dstack-TEE/dstack?tab=readme-ov-file#deploy-an-app).
 
+> **Log retention:** the MPC container is reused across **restarts**, so its
+> logs are preserved and remain viewable here after a restart. An **upgrade**
+> (new image) recreates the container, which clears its logs.
+
 ---
 
 #### Local Access