guest: Wait for a file of gRPC port number getting ready
Some debian services, such as forwarder_guest_launcher and
shutdown_runner, read a gRPC number from a file provided
via virtiofs.
However, since virtiofs and the port number's setup takes some time,
the file soetimes is not ready when systemd tries to start these
daemons. As a result, these daemons could fail to be started
especially at the VM's first boot after installation.
This CL adds a logic to wait for the file getting ready.
Bug: none
Test: Start a VM and check journalctl to ensure the daemons didn't
fail to start.
Change-Id: If5df480815da3ad18f3e412dcabe06e4e7f804ea
diff --git a/guest/shutdown_runner/src/main.rs b/guest/shutdown_runner/src/main.rs
index 397c205..4043002 100644
--- a/guest/shutdown_runner/src/main.rs
+++ b/guest/shutdown_runner/src/main.rs
@@ -26,10 +26,9 @@
#[derive(Parser)]
/// Flags for running command
pub struct Args {
- /// grpc port number
+ /// Path to a file where grpc port number is written
#[arg(long)]
- #[arg(alias = "grpc_port")]
- grpc_port: String,
+ grpc_port_file: String,
}
#[tokio::main]
@@ -38,7 +37,17 @@
let args = Args::parse();
let gateway_ip_addr = netdev::get_default_gateway()?.ipv4[0];
- let server_addr = format!("http://{}:{}", gateway_ip_addr.to_string(), args.grpc_port);
+ // Wait for `grpc_port_file` becomes available.
+ const GRPC_PORT_MAX_RETRY_COUNT: u32 = 10;
+ for _ in 0..GRPC_PORT_MAX_RETRY_COUNT {
+ if std::path::Path::new(&args.grpc_port_file).exists() {
+ break;
+ }
+ debug!("{} does not exist. Wait 1 second", args.grpc_port_file);
+ tokio::time::sleep(std::time::Duration::from_secs(1)).await;
+ }
+ let grpc_port = std::fs::read_to_string(&args.grpc_port_file)?.trim().to_string();
+ let server_addr = format!("http://{}:{}", gateway_ip_addr.to_string(), grpc_port);
debug!("connect to grpc server {}", server_addr);