Here you can learn how you can contribute to Inspektor Gadget.
It’s highly recommended to read the architecture documentation before starting to play with Inspektor Gadget.
Setup developer environment
and clone this repo.
git clone [email protected]:your_account/inspektor-gadget.git.
- Install Docker and Golang .
Building the code
Inspektor Gadget is composed by a client executable and a container image.
A container repository is needed to push the image. The following commands
use the value of the
CONTAINER_REPO env variable, it defaults to
docker.io/kinvolk/gadget if not defined.
Building the client executable
You can compile for your platform by running
To cross compile for all supported platforms, you can run
make kubectl-gadget-all or select a specific one with
make kubectl-gadget-linux-amd64 or
Building the gadget container image
You can build and push the container gadget image by running the following commands:
$ cd gadget-container $ make build $ make push
The BPF code is built using a Docker container, so you don’t have to worry installing the compilers to build it.
- The compilation uses
tools/image-tagto choose the tag of the container image to use according to the branch that you are compiling.
- The container repository is set with the
- You can push the container images to another registry and use the
--imageargument when deploying to the Kuberentes cluster.
- If you wish to make changes to traceloop program, update
gadget.Dockerfileto pick your own image of traceloop.
- As for traceloop, it is also possible to change the BCC to be used as described in BCC section.
- See the minikube section for a faster development cycle.
This repo uses Github actions as CI. It compiles and uploads the Inspektor Gadget executable and gadget container image. It also runs unit and some integration tests. A fork of this project should enable them in the repo settings page and add the following secrets to be able to use them:
CONTAINER_REPO: The container repository to use. Example: docker.io/kinvolk/gadget
CONTAINER_REGISTRY: The registry containing the repo above. Leave empty for Docker Hub. Example: ghcr.io, foo.azurecr.io, gcr.io
CONTAINER_REGISTRY_PASSWORD: Authentication information for the the repo above.
Development environment on minikube
It’s possible to make changes to Inspektor Gadget and test them on minikube locally without pushing container images to any registry.
- Follow the specific installation instructions for minikube.
- Make sure the git repositories
inspektor-gadgetare cloned in sibling directories
- Minikube with the Docker driver does not work for traceloop. You can use another driver, for example:
$ minikube start --driver=kvm2
- Install Inspektor Gadget on minikube as usual:
$ kubectl gadget deploy | kubectl apply -f -
- Make changes in the traceloop repository and compile with
- Generate the new gadget image and deploy it to minikube:
$ make -C gadget-container/ minikube
You can run the different unit tests with:
$ make test
The integration tests use a Kubernetes cluster to deploy and test Inspektor Gadget. Be sure that you have a valid kubeconfig and run:
$ export KUBECONFIG=... # not needed if valid config in $HOME/.kube/config $ make integration-tests
Code of Conduct
Please refer to the Kinvolk Code of Conduct .
For making PRs/commits consistent and easier to review, please check out Kinvolk’s contribution guidelines on git .
Good first issues
Proposing new features
If you want to propose a new feature or do a big change in the architecture it’s highly recommended to open an issue first to discuss it with the team.
Porting BCC gadgets
This project uses some gadgets from BCC . Instead of keeping our patched versions, we prefer to make those gadgets suitable to be used with Inspektor Gadget by contributing to the upstream project.
A BCC gadget has to provide a filtering mechanism by cgroup id and mount namespace id in order to be compatible with Inspektor Gadget. You can get some inspiration from the opensnoop and execsnoop implementations to port a different BCC gadget.
Once the gadget has been updated in the BCC repo, it can be added to Inspektor
Gadget by filling a PR adding the gadget to
add gadget bindsnoop
PR is an example of it.
The adding new BCC-based gadgets in Inspektor Gadget blogpost presents some more details about this process.
Updating BCC from upstream
As you can see in
gadget.Dockerfile, the gadget container image
uses the BCC container image as its parent image.
Given that there is not an official container repository to get that BCC image,
we keep a synchronised
Kinvolk BCC fork
that is configured to publish the images on Kinvolk container registries
, by using the
already available in
Given that, if you want to update the BCC version used by Inspektor Gadget,
it is necessary to first update the
Kinvolk BCC fork
so that the Github actions are triggered, and a new image is published.
Once the image is available in registries, you have to update
gadget.Dockerfile so that it uses the just created image, same goes for local
Update BCC container image
PR is an example of it.
Currently, we use Docker Hub to pull the BCC image when building the gadget
container image. Notice we do not use the
latest tag because it is overwritten
after each push on master branch. Instead, we use the
stable unique tags
that are named with format:
<Timestamp><Commit-SHA>. For instance, tag
202107061407494e8e8c describes that it was created in 2021-07-06 at 14:07:49
from commit SHA starting with