Project Journey Report

Published: November 11, 2024

Introduction

Cilium is an open source platform designed for cloud-native networking, security, and observability, leveraging eBPF technology. It provides secure, high-performance network connectivity and deep visibility for Kubernetes and other cloud environments. Cilium allows for complex and detailed network policies, load balancing, service mesh integration, and comprehensive network observability. It is widely used in production environments by companies like Adobe, Capital One, and Google, offering robust support for large-scale deployments.

Cilium joined CNCF on October 13, 2021 and remained in incubation for just under two years before graduating on October 11, 2023. Now, after three years of growth and development, CNCF proudly presents the Cilium project journey report.

In this report, we guide you through the remarkable growth journey Cilium has experienced under CNCF. We can’t attribute every data point to specific inputs, however we can document and explore the correlations in search of successful decisions and actions. This report is part of a series of project journey reports published by the CNCF.

NOTE: These statistics were collected with the DevStats tool, which CNCF built in collaboration with CNCF project communities. “Contributor” is defined as anyone who made a review, comment, commit, or created a PR or issue.

“… Cilium has always been an open source and open governance project. By donating Cilium to the CNCF, we wanted to encourage adoption by a wider community of contributors and end users and  really demonstrate that we stand behind it being an open project  forever into the future…”

Bill Mulligan

eBPF Community, Isovalent at Cisco and Cilium maintainer

Project Snapshot

3,195+
Contributors
70,531+
Code commits
21,621+
Pull requests
98,705+
Contributions
567+
Contributing companies

Cilium has been utilized by organizations across the globe, including Adobe, Alibaba, AWS, and Google. Additionally, a varied end-user base relies on Cilium for observability, scaling, and security, such as Digital Ocean, Bloomberg, Alibaba, Post Finance, WSO2, Meltwater, and many others.

“With Cilium, our customers compare us differently with other managed Kubernetes providers now because our performance is much better. Latency is the biggest concern for our customers and Cilium gives us a good advantage there. The performance improvement is one of the biggest advantages that we’ve gotten from Cilium and it is great for our business. Cilium also provides many additional functionalities, like Hubble which gives our customers observability.”

BoKang Li

Senior Engineer, Alibaba Cloud

Contributor Diversity

1/7


Cilium’s rapid growth and widespread adoption have been fueled by strong collaboration and a unified vision among its key vendor and end-user contributor communities. Founded by Isovalent, the project has expanded to include significant input from more than 1,000 organizations and thousands of independent contributors, all of whom have played a crucial role in shaping it through its user-driven innovation.

The diversity of vendor contributors is expanding; in 2023, Isovalent, by far the largest Cilium contributor, was acquired by Cisco. Other contributors to Cilium include some of the world’s largest tech companies, such as Google, Cisco, and RedHat, as well as fast-growing mid-size enterprises, like Datadog, Cloudflare, and SUSE. Contributions also come from dozens of smaller businesses and innovative startups. Contributing organizations are well distributed between vendors and end users, demonstrating how end users themselves can help foster and sustain fast-growing, successful projects.

The top two contributing companies to Cilium as of the August 2024 reporting date were Isovalent and Google, with 90% and 1% of contributions, respectively. Isovalent and Cisco provided the majority of code contributions to the project in its first two years, with many additional companies joining the community since then. The number of contributing companies has increased by 90% since Cilium joined CNCF, from 533 to 1,011. This growth corresponds to a rise in individual contributors from 1,269 when it joined to 4,464 today, representing a 252% increase. 

All time contributions to Cilium total over 506,400, an increase of 124% from 225,900 when it joined CNCF. Isovalent’s percentage of all contributions has decreased slightly, but the company has continued to contribute the lion’s share of code, while Google, Datadog, and Cloudflare have expanded their contributions. These factors indicate a healthy dynamic, where project originators have contributed prolifically while encouraging other organizations to increase their contributions, sharing stewardship, and growing the community.

The diversity of company contributors, and the healthy balance of vendor and end user input, continue to fuel growth and give users confidence in choosing Cilium as their cloud native networking, observability, and security solution.



Contributions by company 2016-07-01 – 2024-04-01

Contributions by company 2016-07-01 – 2024-04-01

Percentage breakdown of Cilium contributions by company 2016-07-01 – 2024-08-01

Percentage breakdown of Cilium contributions by company 2016-07-01 – 2024-08-01

Cumulative growth of contributing companies 2016-07-01 – 2024-07-01

Cumulative growth of contributing companies 2016-07-01 – 2024-07-01

Cumulative growth in contributors 2016-07-01 – 2024-07-01

Cumulative growth in contributors 2016-07-01 – 2024-07-01

Geographic Diversity
of Contributors

2/7


Top Contributing Countries

Top Contributing Countries

Percentage contributions to Cilium by country 2016-07-01 – 2024-07-01

Percentage contributions to Cilium by country 2016-07-01 – 2024-07-01

Development
Velocity

3/7


The importance of velocity is that it allows the CNCF, the Linux Foundation, and other stakeholders to track trends and technologies resonating with developers and end users. By observing the velocity of various projects, we can understand which projects are growing, which are maturing, and which are cultivating large communities. This information can then be used to guide decisions and strategies.

Monthly velocity of Cilium

Monthly velocity of Cilium

Based on velocity metrics since joining CNCF, Cilium appears set to continue growing at a robust pace.

One way we track developer velocity (defined by CNCF) is with a simple formula: commits + PRs + issues + authors. We also look at cumulative numbers of contributors throughout Cilium’s history. Both illustrate that Cilium’s formula of multiple vendors and end users fosters healthy grassroots support.

Growth of Cilium pull requests, code commits, issues, and authors 2016-07-01 – 2024-07-01

Growth of Cilium pull requests, code commits, issues, and authors 2016-07-01 – 2024-07-01

Education, Events
& Sponsorship

4/7


The more a project’s community participates in education, events, and sponsorship, the healthier the project tends to be.

CNCF’s flagship KubeCon + CloudNativeCon events in North America, Asia, and Europe have spotlighted Cilium since it joined CNCF in 2021. Cilium has been the subject of numerous keynotes, talks, sessions, meetings, and workshops at these events, attended by tens of thousands annually. The eBPF & Cilium Community YouTube channel offers 364 videos and CNCF’s YouTube channel offers a treasure trove of past Cilium content.  

Cilium will be featured in Cilium + eBPF Day North America 2024 (the fourth conference about Cilium), which focuses on “how Cilium and eBPF are being developed, deployed, and used across the cloud native landscape to revolutionize cloud native platforms.” The event will also feature end users and contributors, as well as eBPF and Cilium specialists all sharing knowledge and insights into Cilium’s impact on businesses through networking, security, and observability. 

Cilium tutorials and courses have emerged to meet the demand for skills in using the project’s software. For example, The Linux Foundation offers a beginner’s Cilium training program to online and corporate learners as well as a Certified Associate certification exam. Additionally, both Cilium and its creator Isovalent, offer training courses and labs online tailored to various skill levels. 

Marketing Growth
& Programs

5/7


Since Cilium joined CNCF in 2021, the project worked diligently to spread awareness of the project and expand its community through two core principles:

  • Solving real problems and being genuine with its audiences.
  • Listening to all inputs from vendors and end users to maintain balance and generate excitement.

Since accepting Cilium, CNCF has covered news related to the project and featured it in case studies on its website. With the Linux Foundation’s support, the team at Isovalent also helped create an “Introduction to Cilium” training course with over 26 hours of material, helping developers, system operators, and security professionals interested in using Cilium enhance their skill-sets in connectivity, observability, and security within Kubernetes. 

“Being a graduated project helped new users recognize that Cilium was already widely adopted at scale, and had become the standard solution for Kubernetes networking and security. It has now been adopted by all the major public clouds, who have also contributed engineering efforts into the project – in some cases, it’s unlikely they would have been able to make these contributions if the project wasn’t independent of a single vendor.”

Liz Rice

Chief Open Source Officer, Isovalent at Cisco

The Cilium website, co-managed by CNCF, has grown robustly since late 2021, with Similarweb reporting over 100,000 page views during Sept 2024, up 31% from the previous month. 

When Cilium joined CNCF, its Twitter account had fewer than 7,500 followers, and as of July 2024, boasts nearly 14,000 followers, having grown its following by over 85%.

The project also has its own YouTube channel, and a dedicated community on Slack, with more than 22,000 members. 

Cilium’s importance within the eBPF-based network observability sphere cannot be understated, it has demonstrated consistent growth and maturity and with a diverse community of adopters and shows no signs of slowing down. 

Cilium was able to become the standard for cloud native networking because it was founded and built on eBPF and eBPF is also helping Cilium tackle the challenges of observability and security with Hubble and Tetragon…”

Bill Mulligan

Cilium and eBPF Community Pollinator, Isovalent at Cisco

Project
Documentation

6/7


Cloud native projects can’t exist without robust documentation for educating new users and helping existing users solve problems. A healthy velocity of documentation changes is a great signal for the health of a project’s community.

To date, more than 350 contributors from many backgrounds and motivations have added to and polished Cilium’s documentation.

NOTE: Documentation for Cilium is authored in .rst files. CNCF uses the DevStats tool to automatically collect and count statistics of all relevant .md files in the Cilium repositories in GitHub.

Growth in participation in Cilium project documentation 2016-07-01 – 2024-07-01

Growth in participation in Cilium project documentation 2016-07-01 – 2024-07-01

Cumulative growth of Cilium project documentation commits 2016-07-01 – 2024-07-01

Cumulative growth of Cilium project documentation commits 2016-07-01 – 2024-07-01

Conclusion

7/7


CNCF is committed to fostering and sustaining an ecosystem of open source, vendor-neutral projects by democratizing state-of-the-art software development and deployment patterns to make technology accessible to everyone.

We hope this report provides a useful window into how CNCF fosters and sustains the growth of Cilium, its team, and the diverse community of individuals and organizations using and shaping the project.