Add pre_backup/post_backup guest api

Author: kvinwang

guest-agent/src/guest_api_service.rs

@@ -18,6 +18,8 @@ use tracing::error;
 
 use crate::{rpc_service::ExternalRpcHandler, AppState};
 
+const BACKUP_LOCK_FILE: &str = "/run/dstack-backup.lock";
+
 pub struct GuestApiHandler {
     state: AppState,
 }
@@ -43,6 +45,7 @@ impl GuestApiRpc for GuestApiHandler {
             device_id: info.device_id,
             app_cert: info.app_cert,
             tcb_info: info.tcb_info,
+            backup_in_progress: fs::metadata(BACKUP_LOCK_FILE).is_ok(),
         })
     }
 
@@ -112,6 +115,20 @@ impl GuestApiRpc for GuestApiHandler {
     async fn list_containers(self) -> Result<ListContainersResponse> {
         list_containers().await
     }
+
+    async fn pre_backup(self) -> Result<()> {
+        fs::OpenOptions::new()
+            .create_new(true)
+            .write(true)
+            .open(BACKUP_LOCK_FILE)
+            .context("Failed to create backup lock file, there is another backup in progress")?;
+        Ok(())
+    }
+
+    async fn post_backup(self) -> Result<()> {
+        fs::remove_file(BACKUP_LOCK_FILE).context("Failed to remove backup lock file")?;
+        Ok(())
+    }
 }
 
 pub(crate) async fn list_containers() -> Result<ListContainersResponse> {

guest-api/proto/guest_api.proto

@@ -22,6 +22,8 @@ message GuestInfo {
   string tcb_info = 5;
   // Device ID
   bytes device_id = 6;
+  // true if backup is in progress
+  bool backup_in_progress = 7;
 }
 
 message IpAddress {
@@ -123,6 +125,8 @@ service GuestApi {
   rpc NetworkInfo(google.protobuf.Empty) returns (NetworkInformation);
   rpc ListContainers(google.protobuf.Empty) returns (ListContainersResponse);
   rpc Shutdown(google.protobuf.Empty) returns (google.protobuf.Empty);
+  rpc PreBackup(google.protobuf.Empty) returns (google.protobuf.Empty);
+  rpc PostBackup(google.protobuf.Empty) returns (google.protobuf.Empty);
 }
 
 service ProxiedGuestApi {
@@ -131,4 +135,6 @@ service ProxiedGuestApi {
   rpc NetworkInfo(Id) returns (NetworkInformation);
   rpc ListContainers(Id) returns (ListContainersResponse);
   rpc Shutdown(Id) returns (google.protobuf.Empty);
+  rpc PreBackup(Id) returns (google.protobuf.Empty);
+  rpc PostBackup(Id) returns (google.protobuf.Empty);
 }

vmm/src/guest_api_service.rs

@@ -51,4 +51,12 @@ impl ProxiedGuestApiRpc for GuestApiHandler {
     async fn shutdown(self, request: Id) -> Result<()> {
         self.guest_agent_client(&request.id)?.shutdown().await
     }
+
+    async fn pre_backup(self, request: Id) -> Result<()> {
+        self.guest_agent_client(&request.id)?.pre_backup().await
+    }
+
+    async fn post_backup(self, request: Id) -> Result<()> {
+        self.guest_agent_client(&request.id)?.post_backup().await
+    }
 }