agent: Add env var comment
Add a comment stating what the server address environment variable is
for.
@@ -21,6 +21,8 @@ const DEFAULT_HOTPLUG_TIMEOUT: time::Duration = time::Duration::from_secs(3);
const DEFAULT_CONTAINER_PIPE_SIZE: i32 = 0;
const VSOCK_ADDR: &str = "vsock://-1";
const VSOCK_PORT: u16 = 1024;
+
+// Environment variable used for development and testing
const SERVER_ADDR_ENV_VAR: &str = "KATA_AGENT_SERVER_ADDR";
// FIXME: unused
