es 1.9&rsquo;s new
<a href=https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.9.md#api-machinery>mutating webhook feature</a> to provide automatic
pod-level proxy injection. Automatic injection requires Kubernetes 1.9 or beyond and
therefore doesn&rsquo;t work on older versions. The alpha initializer mechanism is no longer supported.
<a href=/v1.7/docs/setup/additional-setup/sidecar-injection/#automatic-sidecar-injection>Learn more</a></p></li><li><p><strong>Revised Traffic Rules</st