falco Documentation

File: README.md Copy Chapter

Falco

Falco is a cloud native runtime security tool for Linux operating systems. It is designed to detect and alert on abnormal behavior and potential security threats in real-time.

At its core, Falco is a kernel monitoring and detection agent that observes events, such as syscalls, based on custom rules. Falco can enhance these events by integrating metadata from the container runtime and Kubernetes. The collected events can be analyzed off-host in SIEM or data lake systems.

Falco, originally created by Sysdig, is a graduated project under the Cloud Native Computing Foundation (CNCF) used in production by various organisations.

For detailed technical information and insights into the cyber threats that Falco can detect, visit the official Falco website.

For comprehensive information on the latest updates and changes to the project, please refer to the Change Log.

The Falco Project Copy Chapter

The Falco Project codebase is maintained under the falcosecurity GitHub organization. The primary repository, falcosecurity/falco, holds the source code for the Falco binary, while other sub-projects are hosted in dedicated repositories. This approach of isolating components into specialized repositories enhances modularity and focused development. Notable core repositories include:

• falcosecurity/libs: This repository hosts Falco's core libraries, which constitute the majority of the binary’s source code and provide essential features, such as kernel drivers.
• falcosecurity/rules: It contains the official ruleset for Falco, offering pre-defined detection rules for various security threats and abnormal behaviors.
• falcosecurity/plugins: This repository supports integration with external services through plugins that extend Falco's capabilities beyond syscalls and container events, with plans for evolving specialized functionalities in future releases.
• falcosecurity/falcoctl: A command-line utility designed for managing and interacting with Falco.
• falcosecurity/charts: This repository publishes Helm charts for deploying Falco and its ecosystem. The Falco chart source lives in chart/falco.

For further insights into our repositories and additional details about our governance model, please visit the official hub of The Falco Project: falcosecurity/evolution.

Getting Started with Falco Copy Chapter

If you're new to Falco, begin your journey with our Getting Started guide. For production deployments, please refer to our comprehensive Setup documentation.

As final recommendations before deploying Falco, verify environment compatibility, define your detection goals, optimize performance, choose the appropriate build, and plan for SIEM or data lake integration to ensure effective incident response.

Demo Environment Copy Section

A demo environment is provided via a docker-compose file that can be started on a docker host which includes falco, falcosidekick, falcosidekick-ui and its required redis database. For more information see the docker-compose section

Join the Community Copy Chapter

To get involved with the Falco Project please visit the Community repository to find more information and ways to get involved.

If you have any questions about Falco or contributing, do not hesitate to file an issue or contact the Falco maintainers and community members for assistance.

How to reach out?

• Join the #falco channel on the Kubernetes Slack.
• Join the Falco mailing list.
• File an issue or make feature requests.

Commitment to Falco's Own Security Copy Chapter

Full reports of various security audits can be found here.

In addition, you can refer to the falco and libs security sections for detailed updates on security advisories and policies.

To report security vulnerabilities, please follow the community process outlined in the documentation found here.

Building Copy Chapter

For comprehensive, step-by-step instructions on building Falco from source, please refer to the official documentation.

Testing Copy Chapter

Expand Testing Instructions

Falco's Build Falco from source is the go-to resource to understand how to build Falco from source. In addition, the falcosecurity/libs repository offers additional valuable information about tests and debugging of Falco's underlying libraries and kernel drivers.

Here's an example of a cmake command that will enable everything you need for all unit tests of this repository:

cmake \
-DUSE_BUNDLED_DEPS=ON \
-DBUILD_DRIVER=ON \
-DBUILD_FALCO_MODERN_BPF=ON \
-DCREATE_TEST_TARGETS=ON \
-DBUILD_FALCO_UNIT_TESTS=ON ..;

Build and run the unit test suite:

nproc=$(grep processor /proc/cpuinfo | tail -n 1 | awk '{print $3}');
make -j$(($nproc-1)) falco_unit_tests;
# Run the tests
sudo ./unit_tests/falco_unit_tests;

Optionally, build the driver of your choice and test run the Falco binary to perform manual tests.

Lastly, The Falco Project has moved its Falco regression tests to falcosecurity/testing.

How to Contribute Copy Chapter

Please refer to the Contributing guide and the Code of Conduct for more information on how to contribute.

FAQs Copy Chapter

Why is Falco in C++ rather than Go or {language}? Copy Section

Expand Information

1. The first lines of code at the base of Falco were written some time ago, where Go didn't yet have the same level of maturity and adoption as today.
2. The Falco execution model is sequential and mono-thread due to the statefulness requirements of the tool, and so most of the concurrency-related selling points of the Go runtime would not be leveraged at all.
3. The Falco code deals with very low-level programming in many places, and we all know that interfacing Go with C is possible but brings tons of complexity and tradeoffs to the table.
4. As a security tool meant to consume a crazy high throughput of events per second, Falco needs to squeeze performance in all hot paths at runtime and requires deep control on memory allocation, which the Go runtime can't provide (there's also garbage collection involved).
5. Although Go didn't suit the engineering requirements of the core of Falco, we still thought that it could be a good candidate for writing Falco extensions through the plugin system. This is the main reason we gave special attention and high priority to the development of the plugin-sdk-go.
6. Go is not a requirement for having statically-linked binaries. In fact, we provide fully-static Falco builds since few years. The only issue with those is that the plugin system can't be supported with the current dynamic library model we currently have.
7. The plugin system has been envisioned to support multiple languages, so on our end maintaining a C-compatible codebase is the best strategy to ensure maximum cross-language compatibility.
8. In general, plugins have GLIBC requirements/dependencies because they have low-level C bindings required for dynamic loading. A potential solution for the future could be to also support plugin to be statically-linked at compilation time and so released as bundled in the Falco binary. Although no work started yet in this direction, this would solve most issues you reported and would provide a totally-static binary too. Of course, this would not be compatible with dynamic loading anymore, but it may be a viable solution for our static-build flavor of Falco.
9. Memory safety is definitely a concern and we try our best to keep an high level of quality even though C++ is quite error prone. For instance, we try to use smart pointers whenever possible, we build the libraries with an address sanitizer in our CI, we run Falco through Valgrind before each release, and have ways to stress-test it to detect performance regressions or weird memory usage (e.g. https://github.com/falcosecurity/event-generator). On top of that, we also have third parties auditing the codebase by time to time. None of this make a perfect safety standpoint of course, but we try to maximize our odds. Go would definitely make our life easier from this perspective, however the tradeoffs never made it worth it so far due to the points above.
10. The C++ codebase of falcosecurity/libs, which is at the core of Falco, is quite large and complex. Porting all that code to another language would be a major effort requiring lots of development resource and with an high chance of failure and regression. As such, our approach so far has been to choose refactors and code polishing instead, up until we'll reach an optimal level of stability, quality, and modularity, on that portion of code. This would allow further developments to be smoother and more feasibile in the future.

What's next for Falco? Copy Section

Stay updated with Falco's evolving capabilities by exploring the Falco Roadmap, which provides insights into the features currently under development and planned for future releases.

License Copy Chapter

Falco is licensed to you under the Apache 2.0 open source license.

Resources Copy Chapter

• Governance
• Code Of Conduct
• Maintainers Guidelines
• Maintainers List
• Repositories Guidelines
• Repositories List
• Adopters List
• Release Process
• Setup documentation
• Troubleshooting

File: brand/README.md Copy Chapter

Falco Branding Guidelines

Falco is an open source security project whose brand and identity are governed by the Cloud Native Computing Foundation.

This document describes the official branding guidelines of The Falco Project. Please see the Falco Branding page on our website for further details.

Logo Copy Section

There are 3 logos available for use in this directory. Use the primary logo unless required otherwise due to background issues or printing.

The Falco logo is Apache 2 licensed and free to use in media and publication for the CNCF Falco project.

Colors Copy Section

The primary colors are those in the first two rows.

Slogan Copy Section

Cloud Native Runtime Security

Writing about Falco Copy Section

Yes

Notice the capitalization of the following terms.

• The Falco Project
• Falco

No

• falco
• the falco project
• the Falco project

Glossary

This section contains key terms specifically used within the context of The Falco Project. For a more comprehensive list of Falco-related terminology, we invite you to visit the Glossary page on our official website.

Modern eBPF Probe

Robust eBPF probe, which brings the CO-RE paradigm, better performances, and maintainability.
The modern eBPF probe is not shipped as a separate artifact but bundled into the Falco binary itself.
This is one option used to pass kernel events up to userspace for Falco to consume.

Kernel Module

Used to describe the .ko object that would be loaded into the kernel as a potentially risky kernel module.
This is one option used to pass kernel events up to userspace for Falco to consume.

Driver

The global term for the software that sends events from the kernel. Such as the Modern eBPF probe, or the Kernel Module.

Plugin

Used to describe a dynamic shared library (.so files in Unix, .dll files in Windows) that conforms to a documented API and allows to extend Falco's capabilities.

Falco

The name of the project and also the name of the main engine that the rest of the project is built on.

File: docker/docker-compose/README.md Copy Chapter

Warning

This environment is provided for demonstration purposes only and does not represent a production ready deployment of Falco.

Components

The components that this docker-compose file spins up are Falco, falcosidekick, falcosidekick-ui and a redis database.

Running

To start this environment run docker-compose up.
Note: You may need to use sudo for Falco to start correctly.

Cleaning up

To clean up run docker-compose rm.

Generating events

If you'd like to generate events that will trigger rules and show up in the UI you can run docker run -it --rm falcosecurity/event-generator run syscall --loop

File: docker/README.md Copy Chapter

Falco Dockerfiles

This directory contains various ways to package Falco as a container and related tools.

Currently Supported Images Copy Chapter

File: unit_tests/README.md Copy Chapter

Falco unit tests

Intro Copy Chapter

Under unit_tests/engine and unit_tests/falco directories, we have different test suites that could be a single file or an entire directory according to the number and the complexity of tests.

Build and Run Copy Chapter

cmake -DMINIMAL_BUILD=On -DBUILD_DRIVER=Off -DBUILD_FALCO_UNIT_TESTS=On ..
make falco_unit_tests
sudo ./unit_tests/falco_unit_tests