Development setup

Building and running Tetragon

For local development, you will likely want to build and run bare-metal Tetragon.

Requirements

• A Go toolchain with the version specified in the main go.mod;
• GNU make;
• A running Docker service (you can use Podman as well);
• For building tests, libcap and libelf (in Debian systems, e.g., install libelf-dev and libcap-dev).

Build everything

You can build most Tetragon targets as follows (this can take time as it builds all the targets needed for testing, see minimal build):

make

If you want to use podman instead of docker, you can do the following (assuming you need to use sudo with podman):

CONTAINER_ENGINE='sudo podman' make

You can ignore /bin/sh: docker: command not found in the output.

To build using the local clang, you can use:

CONTAINER_ENGINE='sudo podman' LOCAL_CLANG=1 LOCAL_CLANG_FORMAT=1 make

See Dockerfile.clang for the minimal required version of clang.

Minimal build

To build the tetragon binary, the BPF programs and the tetra CLI binary you can use:

make tetragon tetragon-bpf tetra

Run Tetragon

You should now have a ./tetragon binary, which can be run as follows:

sudo ./tetragon --bpf-lib bpf/objs

Notes:

1. The --bpf-lib flag tells Tetragon where to look for its compiled BPF programs (which were built in the make step above).

2. If Tetragon fails with an error "BTF discovery: candidate btf file does not exist", then make sure that your kernel support BTF, otherwise place a BTF file where Tetragon can read it and specify its path with the --btf flag. See more about that in the FAQ.

Running code generation

Tetragon uses code generation based on protoc to generate large amounts of boilerplate code based on our protobuf API. We similarly use automatic generation to maintain our k8s CRDs. Whenever you make changes to these files, you will be required to re-run code generation before your PR can be accepted.

To run codegen from protoc, run the following command from the root of the repository:

make protogen

And to run k8s CRD generation, run the following command from the root of the repository:

make crds

Finally, should you wish to modify any of the resulting codegen files (ending in .pb.go), do not modify them directly. Instead, you can edit the files in cmd/protoc-gen-go-tetragon and then re-run make protogen.

Running vendor

Tetragon uses multiple modules to separate the main module, from api from pkg/k8s. Depending on your changes you might need to vendor those changes, you can use:

make vendor

Note that the make protogen and make crds commands already vendor changes automatically.

Building and running a Docker image

The base kernel should support BTF or a BTF file should be bind mounted on top of /var/lib/tetragon/btf inside container.

To build Tetragon image:

make image

To run the image:

docker run --name tetragon \
   --rm -it -d --pid=host \
   --cgroupns=host --privileged \
   -v /sys/kernel/btf/vmlinux:/var/lib/tetragon/btf \
   cilium/tetragon:latest

Run the tetra binary to get Tetragon events:

docker exec -it tetragon \
   bash -c "/usr/bin/tetra getevents -o compact"

Building and running as a systemd service

To build Tetragon tarball:

make tarball

Running Tetragon in kind

This command will setup tetragon, kind cluster and install tetragon in it. Ensure docker, kind, kubectl, and helm are installed.

# Setup tetragon on kind
make kind-setup

Verify that Tetragon is installed by running:

kubectl get pods -n kube-system

Local Development in Vagrant Box

If you are on an intel Mac, use Vagrant to create a dev VM:

vagrant up
vagrant ssh
make

If you are getting an error, you can try to run sudo launchctl load /Library/LaunchDaemons/org.virtualbox.startup.plist (from a Stackoverflow answer).

What’s next

• See how to make your first changes.