Added * Users can interrogate the Machine Configuration (i.e. vcpu count and memory size) using a GET request on /machine-config. * The logging system can be configured through the API using a PUT on /logger. * Block devices support live resize by calling PUT with the same parameters as when the block was created. * Release builds have Link Time Optimization (LTO) enabled. * Firecracker is built with musl, resulting in a statically linked binary. * More in-tree integration tests were added as part of the continuous integration system. Changed * The vcpu count is enforced to 1 or an even number. * The Swagger definition of rate limiters was updated. * Syslog-enabled logs were replaced with a hostfile backed mechanism. Fixed * The host topology of the CPU and the caches is not leaked into the microvm anymore. * Boot time was improved by advertising the availability of the TSC deadline timer. * Fixed an issue which prevented Firecracker from working on 4.14 (or newer) host kernels. * Specifying the MAC address for an interface through the API is optional. Removed * Removed support for attaching vsock devices. * Removed support for building Firecracker with glibc.