# mutating-trace-admission-controller

**Repository Path**: mirrors_kubernetes-sigs/mutating-trace-admission-controller

## Basic Information

- **Project Name**: mutating-trace-admission-controller
- **Description**: [EOL] a mutating admission controller which enables experimental tracing of kubernetes object lifecycle
- **Primary Language**: Unknown
- **License**: Apache-2.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2020-08-09
- **Last Updated**: 2025-11-22

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# Mutating trace admission controller

[Mutating admission controller](https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers/#mutatingadmissionwebhook) that injects base64 encoded [OpenCensus span context](https://github.com/census-instrumentation/opencensus-specs/blob/master/trace/Span.md#spancontext) into the `trace.kubernetes.io/context` object annotation.

## Purpose

The trace context injected with this mutating controller can be used by Kubernetes components to export traces associated with object lifecycles. For more information on this effort, [please refer to the official KEP](https://github.com/kubernetes/enhancements/pull/650).

## Quick start

The structure of this mutating admission controller was informed by the [mutating admission webhook found here](https://github.com/morvencao/kube-mutating-webhook-tutorial). The basic idea is as follows:

1) Create an HTTPS-enabled server that takes Pod json from the API server, inserts encoded span context as an annotation, and returns it 
2) Run a deployment with this webhook server, and expose it as a service
3) Create a `MutatingWebhookConfiguration` which instructs the API server to send Pod objects to the aforementioned service upon creation

The included `Makefile` makes these steps straightforward and the available commands are as follows:

* `make docker`: build local Docker image
* `make cluster-up`: apply certificate configuration and deployment configuration to cluster for the mutating webhook
* `make cluster-down`: delete resources associated with the mutating webhook from the active cluster

There are example patches which can be used with `kustomize` to configure the deployment of this webhook into your cluster under `deploy/base/overlays/example`. This example custom configuration can be applied with:  

`kustomize build deploy/overlays/example | kubectl apply -f -`

This can be used, for example, to set different sampling policies between production and staging clusters.

## Community, discussion, contribution, and support

Learn how to engage with the Kubernetes community on the [community page](http://kubernetes.io/community/).

You can reach the maintainers of this project at:

- [Slack channel](https://kubernetes.slack.com/messages/sig-instrumentation)
- [Mailing list](https://groups.google.com/forum/#!forum/kubernetes-sig-instrumentation)

### Code of conduct

Participation in the Kubernetes community is governed by the [Kubernetes Code of Conduct](code-of-conduct.md).