Cilium is open source software for providing and transparently securing the network connectivity between application services deployed using Linux container management platforms like Docker and Kubernetes.
At the foundation of Cilium is a new Linux kernel technology called eBPF, which enables the dynamic insertion of BPF bytecode into the Linux kernel. Cilium generates individual BPF programs for each container to provide networking, security and visibility.
- Cilium Daemon: Agent written in Go. Generates & compiles the BPF programs, manages the BPF maps, and interacts with the local container runtime.
- BPF programs:
- container: Container connectivity & security policies
- netdev: Integration with L3 networks (physical/virtual)
- overlay: Integration with overlay networks (VXLAN, Geneve)
- load balancer: Fast L3/L4 load balancer with direct server return.
- Integrations
- networking frameworks: CNI, libnetwork
- container runtimes: Docker
- orchestration systems: Kubernetes
- logging: logstash
- monitoring:
- Why Cilium?
- Getting Started Guide with Vagrant
- Architecture
- Administrator Guide
- Frequently Asked Questions
- Contributing
Berkeley Packet Filter (BPF) is a Linux kernel bytecode interpreter originally introduced to filter network packets, e.g. for tcpdump and socket filters. The BPF instruction set and surrounding architecture has since been significantly reworked with additional data structures such as hash tables and arrays for keeping state as well as additional actions to support packet mangling, forwarding, encapsulation, etc. Furthermore, a compiler back end for LLVM allows for programs to be written in C and compiled into BPF instructions. An in-kernel verifier ensures that BPF programs are safe to run and a JIT compiler converts the BPF bytecode to CPU architecture specific instructions for native execution efficiency. BPF programs can be run at various hooking points in the kernel such as for incoming packets, outgoing packets, system calls, kprobes, uprobes, tracepoints, etc.
BPF continues to evolve and gain additional capabilities with each new Linux release. Cilium leverages BPF to perform core data path filtering, mangling, monitoring and redirection, and requires BPF capabilities that are in any Linux kernel version 4.8.0 or newer (the latest current stable Linux kernel is 4.10.x).
Many Linux distributions including CoreOS, Debian, Docker's LinuxKit, Fedora,
and Ubuntu already ship kernel versions >= 4.8.x. You can check your Linux
kernel version by running uname -a. If you are not running a recent enough
kernel yet, check the Documentation of your Linux distribution on how to run
Linux kernel 4.9.x or later.
For more detail on kernel versions, see: Prerequisites
XDP is a further step in evolution and enables to run a specific flavor of BPF programs from the network driver with direct access to the packet's DMA buffer. This is, by definition, the earliest possible point in the software stack, where programs can be attached to in order to allow for a programmable, high performance packet processor in the Linux kernel networking data path.
The easiest way to meet the prerequisites is to use the provided vagrant box which provides all prerequisites in a sandbox environment. Please see the vagrant guide for more details.
In order to meet the prerequisites for an installation outside of vagrant, the following components must be installed in at least the version specified:
- Linux kernel (http://www.kernel.org/)
- Minimum: >= 4.8.0
- Recommended: >= 4.9.17. Use of a 4.9.17 kernel or later will ensure compatibility with clang > 3.9.x
- clang+LLVM >=3.7.1. Please note that in order to use clang 3.9.x, the kernel version requirement is >= 4.9.17
- iproute2 >= 4.8.0: https://www.kernel.org/pub/linux/utils/net/iproute2/
Cilium will make use of later kernel versions if available. It will probe for the availability of the functionality automatically. It is therefore perfectly acceptable to use a distribution kernel which has the required functionality backported.
See the Installation instructions
- DockerCon, April 18, 2017: Cilium - Network and Application Security with BPF and XDP
- CNCF/KubeCon Meetup, March 28, 2017: Linux Native, HTTP Aware Network Security
- Docker Distributed Systems Summit, Berlin, Oct 2016: Slides, Video
- NetDev1.2, Tokyo, Sep 2016 - cls_bpf/eBPF updates since netdev 1.1: Slides, Video
- NetDev1.2, Tokyo, Sep 2016 - Advanced programmability and recent updates with tc’s cls_bpf: Slides, Video
- ContainerCon NA, Toronto, Aug 2016 - Fast IPv6 container networking with BPF & XDP: Slides
- NetDev1.1, Seville, Feb 2016 - On getting tc classifier fully programmable with cls_bpf: Slides, Video
- Software Gone Wild by Ivan Pepelnjak, Oct 2016: Blog, MP3
- OVS Orbit by Ben Pfaff, May 2016: Blog, MP3
- Cilium for Network and Application Security with BPF and XDP, Apr 2017: Blog
- Cilium, BPF and XDP, Google Open Source Blog, Nov 2016: Blog
- The developer community is hanging out on zoom on a weekly basis to chat. Everybody is welcome.
- Weekly, Monday, 8am PT, 11am ET, 5pm CEST
- Join zoom
If you have any questions feel free to contact us on Slack
The cilium user space components are licensed under the Apache License, Version 2.0. The BPF code templates are licensed under the General Public License, Version 2.0.