- Apache-2.0 license
- Docs:
- Experimental vhost-based vsock implementation.
- Improved MMDS network stack performance
- If the logging system is not yet initialized (via
PUT /logger
), log events are now sent to stdout/stderr. - Moved the
instance_info_fails
metric underget_api_requests
- Improved readme and added links to more detailed information, now featured in subject-specific docs.
- Fixed bug in the MMDS network stack, that caused some RST packets to be sent without a destination.
- Fixed bug in
PATCH /drives
, whereby the ID in the path was not checked against the ID in the body.
- The Swagger definition was corrected.
- Each Firecracker process has an associated microVM Metadata Store (MMDS). Its
contents can be configured using the
/mmds
API resource.
- The boot source is specified only with the
kernel_image_path
and the optional parameterboot_args
. All other fields are removed. - The
path_on_host
property in the drive specification is now marked as mandatory. - PATCH drive only allows patching/changing the
path_on_host
property. - All PUT and PATCH requests return the status code 204.
- CPUID brand string (aka model name) now includes the host CPU frequency.
- API requests which add guest network interfaces have an additional parameter,
allow_mmds_requests
which defaults tofalse
. - Stopping the guest (e.g. using the
reboot
command) also terminates the Firecracker process. When the Firecracker process ends for any reason, (other thankill -9
), metrics are flushed at the very end. - On startup
jailer
closes all inherited file descriptors based onsysconf(_SC_OPEN_MAX)
except input, output and error. - The microVM ID prefixes each Firecracker log line. This ID also appears
in the process
cmdline
so it's now possible tops | grep <ID>
for it.
- 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.
StartInstance
is a synchronous API request (it used to be an asynchronous request).
- 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
andis_read_only
properties are now marked as required in the Swagger definition ofDrive
object properties.
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 forInstanceStart
, both from the URI and the JSON request body.
- The jailer can now be configured to enter a preexisting network namespace, and to run as a daemon.
- Enabled PATCH operations on
/drives
resources.
- The microVM
id
supplied to the jailer may now contain alphanumeric characters and hyphens, up to a maximum length of 64 characters. - Replaced the
permissions
property of/drives
resources with a boolean. - Removed the
state
property of/drives
resources.
- Rate limiting functionality allows specifying an initial one time burst size.
- Firecracker can now boot from an arbitrary boot partition by specifying its unique id in the driver's API call.
- Block device rescan is triggered via a PUT
/actions
with the drive ID in the action body'spayload
field and theaction_type
field set toBlockDeviceRescan
.
- Removed
noapic
from the default guest kernel command line. - The
action_id
parameter is no longer required for synchronous PUT requests to/actions
. - PUT requests are no longer allowed on
/drives
resources after the guest has booted.
- Fixed guest instance kernel loader to accelerate vCPUs launch and consequently guest kernel boot.
- Fixed network emulation to improve IO performance.
- Firecracker uses two different named pipes to record human readable logs and metrics, respectively.
- Seccomp filtering can be enabled via setting the
USE_SECCOMP
environment variable. - It is possible to supply only a partial specification when attaching a rate limiter (i.e. just the bandwidth or ops parameter).
- Errors related to guest network interfaces are now more detailed.
- Fixed a bug that was causing Firecracker to panic whenever a
PUT
request was sent on an existing network interface. - The
id
parameter of thejailer
is required to be an RFC 4122-compliant UUID. - Fixed an issue which caused the network RX rate limiter to be more restrictive than intended.
- API requests which contain unknown fields will generate an error.
- Fixed an issue related to high CPU utilization caused by improper
KVM PIT
configuration. - It is now possible to create more than one network tun/tap interface inside a jailed Firecracker.
- Added metrics for API requests, VCPU and device actions for the serial
console (
UART
), keyboard (i8042
), block and network devices. Metrics are logged every 60 seconds. - A CPU features template for C3 is available, in addition to the one for T2.
- Seccomp filters restrict Firecracker from calling any other system calls than
the minimum set it needs to function properly. The filters are enabled by
setting the
USE_SECCOMP
environment variable to 1 before running Firecracker. - Firecracker can be started by a new binary called
jailer
. The jailer takes as command line arguments a unique ID, the path to the Firecracker binary, the NUMA node that Firecracker will be assigned to and auid
andgid
for Firecracker to run under. It sets up achroot
environment and acgroup
, and calls exec to morph into Firecracker.
- In case of failure, the metrics and the panic location are logged before aborting.
- Metric values are reset with every flush.
CPUTemplate
is now calledCpuTemplate
in order to work seamlessly with the swagger code generator for Go.firecracker-beta.yaml
is now calledfirecracker.yaml
.
- Handling was added for several untreated KVM exit scenarios, which could have led to panic.
- Fixed a bug that caused Firecracker to crash when attempting to disable the
IA32_DEBUG_INTERFACE MSR
flag in the T2 CPU features.
- Removed a leftover file generated by the logger unit tests.
- Removed
firecracker-v1.0.yaml
.
- The CPU Template can be set with an API call on
PUT /machine-config
. The only available template is T2. - Hyperthreading can be enabled/disabled with an API call on
PUT /machine-config
. By default, hyperthreading is disabled. - Added boot time performance test (
tests/performance/test_boottime.py
). - Added Rate Limiter for VirtIO/net and VirtIO/net devices. The Rate Limiter
uses two token buckets to limit rate on bytes/s and ops/s. The rate limiter
can be (optionally) configured per drive with a
PUT
on/drives/{drive_id}
and per network interface with aPUT
on/network-interface/{iface_id}
. - Implemented pre-boot PUT updates for
/boot-source
,/drives
,/network-interfaces
and/vsock
. - Added integration tests for
PUT
updates.
- Moved the API definition (
swagger/firecracker-beta.yaml
) to theapi_server
crate. - Removed
"console=ttyS0"
and added"8250.nr_uarts=0"
to the default kernel command line to decrease the boot time. - Changed the CPU topology to have all logical CPUs on a single socket.
- Removed the upper bound on CPU count as with musl there is no good way to get the total number of logical processors on a host.
- Build time tests now print the full output of commands.
- Disabled the Performance Monitor Unit and the Turbo Boost.
- Check the expected KVM capabilities before starting the VM.
- Logs now have timestamps.
testrun.sh
can run on platforms with more than one package manager by setting the package manager via a command line parameter (-p
).- Allow correct set up of multiple network-interfaces with auto-generated MAC.
- Fixed sporadic bug in VirtIO which was causing lost packages.
- Don't allow
PUT
requests with empty body on/machine-config
. - Deny
PUT
operations after the microvm boots (exception: the temporarily fix for live resize of block devices).
- Removed examples crate. This used to have a Python example of starting
Firecracker. This is replaced by
test_api.py
integration tests. - Removed helper scripts for getting coverage and coding style errors. These
were replaced by
test_coverage.py
andtest_style.py
test integration tests. - Removed
--vmm-no-api
command line option. Firecracker can only be started via the API.
- 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.
- 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 host-file backed mechanism.
- 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 support for attaching vsock devices.
- Removed support for building Firecracker with glibc.
- Users can now interrogate Instance Information (currently just instance state) through the API.
- Renamed
api/swagger/all.yaml
toapi/swagger/firecracker-v1.0.yaml
which specifies targeted API support for Firecracker v1.0. - Renamed
api/swagger/firecracker-v0.1.yaml
toapi/swagger/firecracker-beta.yaml
which specifies the currently supported API. - Users can now enforce that an emulated block device is read-only via the API.
To specify whether a block device is read-only or read-write, an extra
"permissions" field was added to the Drive definition in the API. The root
filesystem is automatically mounted in the guest OS as
ro
/rw
according to the specified "permissions". It's the responsibility of the user to mount any other read-only block device as such within the guest OS. - Users can now stop the guest VM using the API. Actions of type
InstanceHalt
are now supported via the API.
- Added support for
getDeviceID()
invirtIO-block
. Without this, the guest Linux kernel would complain at boot time that the operation is unsupported. stdin
control is returned to the Firecracker process when guest VM is inactive. Raw modestdin
is forwarded to the guest OS when guest VM is running.
- Removed
api/swagger/actions.yaml
. - Removed
api/swagger/devices.yaml
. - Removed
api/swagger/firecracker-mvp.yaml
. - Removed
api/swagger/limiters.yaml
.
- Users can now specify the MAC address of a guest network interface via the
PUT
network interface API request. Previously, the guest MAC address parameter was ignored.
- Fixed a guest memory allocation issue, which previously led to a potentially significant memory chunk being wasted.
- Fixed an issue which caused compilation problems, due to a compatibility breaking transitive dependency in the tokio suite of crates.
- One-process virtual machine manager (one Firecracker per microVM).
- RESTful API running on a unix socket. The API supported by v0.1 can be found
at
api/swagger/firecracker-v0.1.yaml
. - Emulated keyboard (
i8042
) and serial console (UART
). The microVM serial console input and output are connected to those of the Firecracker process (this allows direct console access to the guest OS). - The capability of mapping an existing host tun-tap device as a VirtIO/net device into the microVM.
- The capability of mapping an existing host file as a GirtIO/block device into the microVM.
- The capability of creating a VirtIO/vsock between the host and the microVM.
- Default demand fault paging & CPU oversubscription.