firectl is a command-line tool to run Firecracker microVMs
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Latest commit 86d926d Jan 14, 2019


Firectl is a basic command-line tool that lets you run arbitrary Firecracker MicroVMs via the command line. This lets you run a fully functional Firecracker MicroVM, including console access, read/write access to filesystems, and network connectivity.


We use go modules, so you need to build with Go 1.11 or newer. go build or make should be sufficient to generate a working firectl binary.


You'll need to have a firecracker build, as well as an uncompressed Linux kernel image (vmlinux) and root filesystem image.

By default, firectl searches PATH for the firecracker binary. The location of the kernel and filesystem image must be provided explicitly.

  firectl [OPTIONS]

Application Options:
      --firecracker-binary=     Path to firecracker binary
      --kernel=                 Path to the kernel image (default: ./vmlinux)
      --kernel-opts=            Kernel commandline (default: ro console=ttyS0 noapic reboot=k panic=1 pci=off nomodules)
      --root-drive=             Path to root disk image
      --root-partition=         Root partition UUID
      --add-drive=              Path to additional drive, suffixed with :ro or :rw, can be specified multiple times
      --tap-device=             NIC info, specified as DEVICE/MAC
      --vsock-device=           Vsock interface, specified as PATH:CID. Multiple OK
      --vmm-log-fifo=           FIFO for firecracker logs
      --log-level=              vmm log level (default: Debug)
      --metrics-fifo=           FIFO for firecracker metrics
  -t, --disable-hyperthreading  Disable CPU Hyperthreading
  -c, --ncpus=                  Number of CPUs (default: 1)
      --cpu-template=           Firecracker CPU Template (C3 or T2)
  -m, --memory=                 VM memory, in MiB (default: 512)
      --metadata=               Firecracker Metadata for MMDS (json)
  -l, --firecracker-log=        pipes the fifo contents to the specified file
  -s, --socket-path=            path to use for firecracker socket, defaults to a unique file in in the first existing directory from {$HOME, $TMPDIR, or /tmp}
  -d, --debug                   Enable debug output

Help Options:
  -h, --help                    Show this help message


firectl \
  --kernel=~/bin/vmlinux \
  --root-drive=/images/image-debootstrap.img -t \
  --cpu-template=T2 \
  --firecracker-log=~/firecracker-vmm.log \
  --kernel-opts="console=ttyS0 noapic reboot=k panic=1 pci=off nomodules rw" \
  --vsock-device=root:3 \

Getting Started on AWS

  • Create an i3.metal instance using Amazon Linux 2

  • Build latest version of firectl:

    sudo yum install -y git
    git clone
    sudo amazon-linux-extras install -y golang1.11
    cd firectl
  • Get Firecracker binary:

    curl -LOJ
    chmod +x firecracker-v0.12.0
    sudo mv firecracker-v0.12.0 /usr/local/bin/firecracker
  • Give read/write access to KVM:

    sudo setfacl -m u:${USER}:rw /dev/kvm
  • Download kernel and root filesystem:

    curl -fsSL -o hello-vmlinux.bin
    curl -fsSL -o hello-rootfs.ext4
  • Create microVM:

    ./firectl \
      --kernel=hello-vmlinux.bin \
      --root-drive=hello-rootfs.ext4 \
      --kernel-opts="console=ttyS0 noapic reboot=k panic=1 pci=off nomodules rw"