istiod. This value is embedded as an environment
variable (<code>ISTIO_META_ISTIO_VERSION</code>) in the Istio proxy docker
image. Custom proxy implementations should provide this metadata
variable to take advantage of the Istio version check option.</p>

</td>
</tr>
<tr id="EnvoyFilter-ProxyMatch-metadata">
<td><div class="field"><div class="name"><code><a href="#EnvoyFilter-ProxyMatch-metadata">metadata</a></code></div>
<div class="type">map&lt;string,&nbsp;string&gt;</div>
</div></td>
<td>
<p>Match on th