Here you can learn how you can contribute to Inspektor Gadget.
To better understand how the pieces fit together, we recommend reading 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 , Docker Buildx and Golang .
- To be able to cross build our different container images, you will also need
Building the code
Inspektor Gadget is composed of a client executable that runs on the operator’s machine, and a container image that runs in the Kubernetes cluster. They can be built together or independently.
Building the client executable
You can compile the client executable 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:
$ make gadget-container $ make push-gadget-container
The eBPF code is built using a Docker container, so you don’t have to worry installing the compilers to build it.
If you push the container images to another registry, you can use the
argument when deploying to the Kubernetes cluster.
- Using a locally built container image requires pushing it to a container
registry, either local or remote. The default registry can be overridden by
changing the value of the
CONTAINER_REPOenv variable, which defaults to
ghcr.io/inspektor-gadget/inspektor-gadgetif not defined.
- The compilation uses
tools/image-tagto choose the tag of the container image to use according to the branch that you are compiling.
- It is also possible to change the BCC to be used as described in BCC section.
- You can generate the required BTF information for some well known
kernel versions by setting
Building the eBPF object files
If you need to compile the eBPF code of the gadgets, the ebpf-objects target will help you in this task:
$ make ebpf-objects ... go: downloading github.com/giantswarm/crd-docs-generator v0.7.1 ... Wrote /work/pkg/gadgettracermanager/containers-map/containersmap_bpfel.go
Inspektor Gadget also provides the
trace containers without Kubernetes. It can be built independently from the
kubectl-gadget and the gadget container image.
$ make ig
Development environment on minikube
For faster iteration, 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
for minikube or use
make minikube-startto start it.
- Deploy the locally modified version of Inspektor Gadget to an already
running minikube cluster with
You can run the different unit tests with:
$ make test
Some unit tests depend on precompiled files on testdata . These files can be regenerated by running
$ make testdata
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
Integration tests for
The integration tests for
ig uses minikube for testing different container runtimes.
The default minikube driver used for testing is
docker. Currently supported
container runtimes are
cri-o. You can start minikube using:
$ make minikube-start-all # for single container runtime e.g containerd $ make CONTAINER_RUNTIME=containerd minikube-start # for minikube driver other than docker e.g kvm2 $ make MINIKUBE_DRIVER=kvm2 minikube-start
And run the test using:
$ make -C integration/ig/k8s test-all # for single container runtime e.g containerd $ make -C integration/ig/k8s CONTAINER_RUNTIME=containerd test
CONTAINER_RUNTIME is specified
docker will be used as a default runtime.
ig integration tests for non-Kubernetes containers directly interact
with container runtime. The tests assume that you already have the desired container
runtime installed. Currently supported runtime is
docker only, You can run the test using:
$ make -C integration/ig/non-k8s test-docker
You can run the different benchmark tests with:
$ make gadgets-benchmarks
Or you can run an individual test with:
$ go test -exec sudo \ -bench='BenchmarkAllGadgetsWithContainers/container10$/trace-tcpconnect' \ -run=Benchmark \ ./internal/benchmarks/...
Explaining performance improvements in a PR
If you want to contribute a performance improvement, it is useful to use benchmarks to explain the impact on performances. I will use the example of an improvement on the networking gadgets from #1430 :
- Run the benchmarks both on the
mainand the feature branches and saving the output in two files.
$ git checkout main $ go test -exec sudo \ -bench='^BenchmarkAllGadgetsWithContainers$/^container100$/trace-(dns|sni)' \ -run=Benchmark \ ./internal/benchmarks/... \ -count 10 | tee main.bench $ git checkout myfeature $ go test -exec sudo \ -bench='^BenchmarkAllGadgetsWithContainers$/^container100$/trace-(dns|sni)' \ -run=Benchmark \ ./internal/benchmarks/... \ -count 10 | tee patched.bench
-count to gather a statistically significant sample of results.
recommends 10 times.
- Compare the results with
$ go install golang.org/x/perf/cmd/benchstat@latest # if not already installed $ benchstat main.bench patched.bench goos: linux goarch: amd64 pkg: github.com/inspektor-gadget/inspektor-gadget/internal/benchmarks cpu: Intel(R) Core(TM) i7-6500U CPU @ 2.50GHz │ main.bench │ patched.bench │ │ sec/op │ sec/op vs base │ AllGadgetsWithContainers/container100/trace-dns-4 2.941 ± 3% 1.489 ± 4% -49.38% (p=0.000 n=10) AllGadgetsWithContainers/container100/trace-sni-4 4.440 ± 19% 1.495 ± 6% -66.34% (p=0.000 n=10) geomean 3.613 1.492 -58.72%
- Include the commands used and the output of
benchstatin your pull request description
You can run the different benchmark tests while using the
bcc profile tool
To be able to see the symbols in the profile, you need to build the binary with
$ go test -exec sudo \ -ldflags="-s=false" \ -bench='^BenchmarkAllGadgetsWithContainers$/^container100$/snapshot-socket' \ -run=Benchmark \ ./internal/benchmarks/... \ -count 100
Example of output showing a stack trace including both the userspace and kernel parts:
$ sudo /usr/share/bcc/tools/profile -p $(pidof benchmarks.test) b'established_get_first' b'established_get_first' b'tcp_seek_last_pos' b'bpf_iter_tcp_batch' b'bpf_iter_tcp_seq_next' b'bpf_seq_read' b'vfs_read' b'ksys_read' b'do_syscall_64' b'entry_SYSCALL_64_after_hwframe' runtime/internal/syscall.Syscall6 syscall.Syscall syscall.read internal/poll.(*FD).Read os.(*File).Read bufio.(*Scanner).Scan github.com/inspektor-gadget/inspektor-gadget/pkg/gadgets/snapshot/socket/tracer.(*Tracer).RunCollector.func1 github.com/inspektor-gadget/inspektor-gadget/pkg/netnsenter.NetnsEnter github.com/inspektor-gadget/inspektor-gadget/pkg/gadgets/snapshot/socket/tracer.(*Tracer).RunCollector github.com/inspektor-gadget/inspektor-gadget/pkg/gadgets/snapshot/socket/tracer.(*Tracer).Run github.com/inspektor-gadget/inspektor-gadget/pkg/runtime/local.(*Runtime).RunGadget github.com/inspektor-gadget/inspektor-gadget/internal/benchmarks.BenchmarkAllGadgetsWithContainers.func1.1 testing.(*B).runN testing.(*B).launch testing.(*B).doBench.func1 runtime.goexit.abi0 - benchmarks.test (3452330) 22
It is also possible to use
the benchmarks with the
go test \ -cpuprofile cpu.prof -memprofile mem.prof \ -exec sudo \ -ldflags="-s=false" \ -bench='^BenchmarkAllGadgetsWithContainers$/^container100$/snapshot-socket' \ -run=Benchmark ./internal/benchmarks/... \ -count 5 $ go tool pprof -top cpu.prof $ go tool pprof -top mem.prof
Inspektor Gadget uses GitHub Actions as CI. Please check dedicated CI documentation for more details.
Some integration tests (like AKS and ARO) are only run when a commit is pushed to the main branch or
a new tag is pushed. It’s also possible to run those by pusing a branch named
notice that the container images will be pushed to
should be manually cleaned up.
Code of Conduct
Inspektor Gadget follows the CNCF Code of Conduct .
For making PRs/commits consistent and easier to review, please check out Kinvolk’s contribution guidelines on git .
We require all commits on a PR to be signed off certifying the Developer Certificate of Origin :
Developer Certificate of Origin Version 1.1 Copyright (C) 2004, 2006 The Linux Foundation and its contributors. Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. Developer's Certificate of Origin 1.1 By making a contribution to this project, I certify that: (a) The contribution was created in whole or in part by me and I have the right to submit it under the open source license indicated in the file; or (b) The contribution is based upon previous work that, to the best of my knowledge, is covered under an appropriate open source license and I have the right under that license to submit that work with modifications, whether created in whole or in part by me, under the same open source license (unless I am permitted to submit under a different license), as indicated in the file; or (c) The contribution was provided directly to me by some other person who certified (a), (b) or (c) and I have not modified it. (d) I understand and agree that this project and the contribution are public and that a record of the contribution (including all personal information I submit with it, including my sign-off) is maintained indefinitely and may be redistributed consistent with this project or the open source license(s) involved.
It can be done by using
git commit -s,
git commit --sign-off or by manually adding a line like
to the commit message.
Signed-off-by: Joe Smith <[email protected]>
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.
github.com/stretchr/testify to make tests less verbose.
Our planning is published through two different project boards:
- Inspektor Gadget Roadmap has the high level view of the big issues that we are planning to tackle in the upcoming months.
- Inspektor Gadget Sprint Planning has the week-to-week plans of which bugs we are currently working on, and the different priorities of the issues involved.
Porting BCC gadgets
This project uses some gadgets based on BCC . In the past, we modified the BCC gadgets and executed them from our process, however it was very inflexible and we decided to integrate those gadgets directly into our code base by rewriting their control plane in Golang.
If you want to implement support for a BCC gadget, please read the Rewriting the Control Plane of BCC Tools in Golang blogpost that contains all the details about this process.
For security, we invite you to take at look at the dedicated document .