nvoyFilter resource to all workloads
(sidecars and gateways) in the system, define the resource in the
config <a href="/zh/docs/reference/config/istio.mesh.v1alpha1/#MeshConfig">root
namespace</a>,
without a workloadSelector.</p>
<p>The example below declares a global default EnvoyFilter resource in
the root namespace called <code>istio-config</code>, that adds a custom
protocol filter on all sidecars in the system, for outbound port
9307. The filter should be added before the terminating tcp_proxy
filter t