Firecracker v0.9.0

Added

• Seccomp filtering is configured via the --seccomp-level jailer parameter.
• Firecracker logs the starting addresses of host memory areas provided as guest
  memory slots to KVM.
• The metric panic_count gets incremented to signal that a panic has occurred.
• Firecracker logs a backtrace when it crashes following a panic.
• Added basic instrumentation support for measuring boot time.

Changed

• StartInstance is a synchronous API request (it used to be an asynchronous
  request).

Fixed

• Ensure that fault messages sent by the API have valid JSON bodies.
• Use HTTP response code 500 for internal Firecracker errors, and 400 for user
  errors on InstanceStart.
• Serialize the machine configuration fields to the correct data types (as specified
  in the Swagger definition).
• NUMA node assignment is properly enforced by the jailer.
• The is_root_device and is_read_only properties are now marked as required
  in the Swagger definition of Drive object properties.

Removed

• GET requests on the /actions API resource are no longer supported.
• The metrics associated with asynchronous actions have been removed.
• Remove the action_id parameter for InstanceStart, both from the URI and the
  JSON request body.