Skip to content

Build_custom_kernel.md

Latest commit

 

History

History
66 lines (55 loc) · 1.86 KB

Build_custom_kernel.md

File metadata and controls

66 lines (55 loc) · 1.86 KB

Building a custom kernel

You need to build a custom kernel if you want to:

  • have the latest kernel minor version
  • add kernel modules like i.e. nf_tables that is used by docker

Clone Firecracker Repository

The official repo contains helper scripts and other ressources.

git clone https://github.com/firecracker-microvm/firecracker/

cd firecracker/resources

vi guest_configs/microvm-kernel-ci-x86_64-6.1.config

#for ARM: vi guest_configs/microvm-kernel-ci-aarch64-6.1.config

./rebuild.sh kernels 6.1

See ./rebuild.sh help for more options.

Note: This script will check and install dependencies on the system, like for example docker. However it will try to install Ubuntu's docker.io, when you already have Docker running on the host, change the the apt install-line to use docker-ce instead.

Sample kernel config for nft support

If you want to runner Docker inside a Firecracker microVM, you'll need a kernel with nft support. Here's what you need to add to microvm-kernel-ci-x86_64-6.1.config to achieve this:

CONFIG_NF_TABLES=y
CONFIG_NFT_NUMGEN=y
CONFIG_NFT_CT=y
CONFIG_NFT_FLOW_OFFLOAD=y
CONFIG_NFT_CONNLIMIT=y
CONFIG_NFT_LOG=y
CONFIG_NFT_LIMIT=y
CONFIG_NFT_MASQ=y
CONFIG_NFT_REDIR=y
CONFIG_NFT_NAT=y
CONFIG_NFT_TUNNEL=y
CONFIG_NFT_QUEUE=y
CONFIG_NFT_QUOTA=y
CONFIG_NFT_REJECT=y
CONFIG_NFT_REJECT_INET=y
CONFIG_NFT_COMPAT=y
CONFIG_NFT_HASH=y
CONFIG_NFT_FIB=y
CONFIG_NFT_FIB_INET=y
CONFIG_NFT_XFRM=y
CONFIG_NFT_SOCKET=y
CONFIG_NFT_OSF=y
CONFIG_NFT_TPROXY=y
CONFIG_NFT_SYNPROXY=y
CONFIG_NFT_DUP_NETDEV=y
CONFIG_NFT_FWD_NETDEV=y
CONFIG_NFT_FIB_NETDEV=y
CONFIG_NFT_REJECT_NETDEV=y
CONFIG_NFT_REJECT_IPV4=y
CONFIG_NFT_DUP_IPV4=y
CONFIG_NFT_FIB_IPV4=y
CONFIG_NFT_REJECT_IPV6=y
CONFIG_NFT_DUP_IPV6=y
CONFIG_NFT_FIB_IPV6=y
CONFIG_NFT_BRIDGE_META=y
CONFIG_NFT_BRIDGE_REJECT=y