Sync docs from master to gh-pages

multi/multi_gateway-route-filters.html

@@ -50,7 +50,17 @@
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        uri</span>: http://example.org
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        filters</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        - PrefixPath</span>=/mypath</pre><p>
-</p><p>This will prefix <code class="literal">/mypath</code> to the path of all matching requests. So a request to <code class="literal">/hello</code>, would be sent to <code class="literal">/mypath/hello</code>.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_requestratelimiter_gatewayfilter_factory" href="#_requestratelimiter_gatewayfilter_factory"></a>5.6&nbsp;RequestRateLimiter GatewayFilter Factory</h2></div></div></div><p>The RequestRateLimiter GatewayFilter Factory takes three parameters: <code class="literal">replenishRate</code>, <code class="literal">burstCapacity</code> &amp; <code class="literal">keyResolverName</code>.</p><p><code class="literal">replenishRate</code> is how many requests per second do you want a user to be allowed to do.</p><p><code class="literal">burstCapacity</code> TODO: document burst capacity</p><p><code class="literal">keyResolver</code> is a bean that implements the <code class="literal">KeyResolver</code> interface. In configuration, reference the bean by name using SpEL. <code class="literal">#{@myKeyResolver}</code> is a SpEL expression referencing a bean with the name <code class="literal">myKeyResolver</code>.</p><p><b>KeyResolver.java.&nbsp;</b>
+</p><p>This will prefix <code class="literal">/mypath</code> to the path of all matching requests. So a request to <code class="literal">/hello</code>, would be sent to <code class="literal">/mypath/hello</code>.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_preservehostheader_gatewayfilter_factory" href="#_preservehostheader_gatewayfilter_factory"></a>5.6&nbsp;PreserveHostHeader GatewayFilter Factory</h2></div></div></div><p>The PreserveHostHeader GatewayFilter Factory has not parameters. This filter, sets a request attribute that the routing filter will inspect to determine if the original host header should be sent, rather than the host header determined by the http client.</p><p><b>application.yml.&nbsp;</b>
+</p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">spring</span>:
+<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">  cloud</span>:
+<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">    gateway</span>:
+<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">      routes</span>:
+<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">      # </span>=====================================
+<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">      - id</span>: preserve_host_route
+<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        uri</span>: http://example.org
+<span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        filters</span>:
+        - PreserveHostHeader</pre><p>
+</p><p>This will prefix <code class="literal">/mypath</code> to the path of all matching requests. So a request to <code class="literal">/hello</code>, would be sent to <code class="literal">/mypath/hello</code>.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_requestratelimiter_gatewayfilter_factory" href="#_requestratelimiter_gatewayfilter_factory"></a>5.7&nbsp;RequestRateLimiter GatewayFilter Factory</h2></div></div></div><p>The RequestRateLimiter GatewayFilter Factory takes three parameters: <code class="literal">replenishRate</code>, <code class="literal">burstCapacity</code> &amp; <code class="literal">keyResolverName</code>.</p><p><code class="literal">replenishRate</code> is how many requests per second do you want a user to be allowed to do.</p><p><code class="literal">burstCapacity</code> TODO: document burst capacity</p><p><code class="literal">keyResolver</code> is a bean that implements the <code class="literal">KeyResolver</code> interface. In configuration, reference the bean by name using SpEL. <code class="literal">#{@myKeyResolver}</code> is a SpEL expression referencing a bean with the name <code class="literal">myKeyResolver</code>.</p><p><b>KeyResolver.java.&nbsp;</b>
 </p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">public</span> <span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">interface</span> KeyResolver {
 	Mono&lt;String&gt; resolve(ServerWebExchange exchange);
 }</pre><p>
@@ -69,7 +79,7 @@
 KeyResolver userKeyResolver() {
     <span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">return</span> exchange -&gt; Mono.just(exchange.getRequest().getQueryParams().getFirst(<span xmlns:d="http://docbook.org/ns/docbook" class="hl-string">"user"</span>));
 }</pre><p>
-</p><p>This defines a request rate limit of 10 per user. The <code class="literal">KeyResolver</code> is a simple one that gets the <code class="literal">user</code> request parameter (note: this is not recommended for production).</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_redirectto_gatewayfilter_factory" href="#_redirectto_gatewayfilter_factory"></a>5.7&nbsp;RedirectTo GatewayFilter Factory</h2></div></div></div><p>The RedirectTo GatewayFilter Factory takes a <code class="literal">status</code> and a <code class="literal">url</code> parameter. The status should be a 300 series redirect http code, such as 301. The url should be a valid url. This will be the value of the <code class="literal">Location</code> header.</p><p><b>application.yml.&nbsp;</b>
+</p><p>This defines a request rate limit of 10 per user. The <code class="literal">KeyResolver</code> is a simple one that gets the <code class="literal">user</code> request parameter (note: this is not recommended for production).</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_redirectto_gatewayfilter_factory" href="#_redirectto_gatewayfilter_factory"></a>5.8&nbsp;RedirectTo GatewayFilter Factory</h2></div></div></div><p>The RedirectTo GatewayFilter Factory takes a <code class="literal">status</code> and a <code class="literal">url</code> parameter. The status should be a 300 series redirect http code, such as 301. The url should be a valid url. This will be the value of the <code class="literal">Location</code> header.</p><p><b>application.yml.&nbsp;</b>
 </p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">spring</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">  cloud</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">    gateway</span>:
@@ -79,7 +89,7 @@ KeyResolver userKeyResolver() {
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        uri</span>: http://example.org
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        filters</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        - RedirectTo</span>=<span class="hl-number">302</span><span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">,</span> http://acme.org</pre><p>
-</p><p>This will send a status 302 with a <code class="literal">Location:http://acme.org</code> header to perform a redirect.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_removenonproxyheaders_gatewayfilter_factory" href="#_removenonproxyheaders_gatewayfilter_factory"></a>5.8&nbsp;RemoveNonProxyHeaders GatewayFilter Factory</h2></div></div></div><p>The RemoveNonProxyHeaders GatewayFilter Factory removes headers from forwarded requests. The default list of headers that is removed comes from the <a class="link" href="https://tools.ietf.org/html/draft-ietf-httpbis-p1-messaging-14#section-7.1.3" target="_top">IETF</a>.</p><div class="itemizedlist"><p class="title"><b>The default removed headers are:</b></p><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">Connection</li><li class="listitem">Keep-Alive</li><li class="listitem">Proxy-Authenticate</li><li class="listitem">Proxy-Authorization</li><li class="listitem">TE</li><li class="listitem">Trailer</li><li class="listitem">Transfer-Encoding</li><li class="listitem">Upgrade</li></ul></div><p>To change this, set the <code class="literal">spring.cloud.gateway.filter.remove-non-proxy-headers.headers</code> property to the list of header names to remove.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_removerequestheader_gatewayfilter_factory" href="#_removerequestheader_gatewayfilter_factory"></a>5.9&nbsp;RemoveRequestHeader GatewayFilter Factory</h2></div></div></div><p>The RemoveRequestHeader GatewayFilter Factory takes a <code class="literal">name</code> parameter. It is the name of the header to be removed.</p><p><b>application.yml.&nbsp;</b>
+</p><p>This will send a status 302 with a <code class="literal">Location:http://acme.org</code> header to perform a redirect.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_removenonproxyheaders_gatewayfilter_factory" href="#_removenonproxyheaders_gatewayfilter_factory"></a>5.9&nbsp;RemoveNonProxyHeaders GatewayFilter Factory</h2></div></div></div><p>The RemoveNonProxyHeaders GatewayFilter Factory removes headers from forwarded requests. The default list of headers that is removed comes from the <a class="link" href="https://tools.ietf.org/html/draft-ietf-httpbis-p1-messaging-14#section-7.1.3" target="_top">IETF</a>.</p><div class="itemizedlist"><p class="title"><b>The default removed headers are:</b></p><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">Connection</li><li class="listitem">Keep-Alive</li><li class="listitem">Proxy-Authenticate</li><li class="listitem">Proxy-Authorization</li><li class="listitem">TE</li><li class="listitem">Trailer</li><li class="listitem">Transfer-Encoding</li><li class="listitem">Upgrade</li></ul></div><p>To change this, set the <code class="literal">spring.cloud.gateway.filter.remove-non-proxy-headers.headers</code> property to the list of header names to remove.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_removerequestheader_gatewayfilter_factory" href="#_removerequestheader_gatewayfilter_factory"></a>5.10&nbsp;RemoveRequestHeader GatewayFilter Factory</h2></div></div></div><p>The RemoveRequestHeader GatewayFilter Factory takes a <code class="literal">name</code> parameter. It is the name of the header to be removed.</p><p><b>application.yml.&nbsp;</b>
 </p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">spring</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">  cloud</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">    gateway</span>:
@@ -89,7 +99,7 @@ KeyResolver userKeyResolver() {
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        uri</span>: http://example.org
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        filters</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        - RemoveRequestHeader</span>=X-Request-Foo</pre><p>
-</p><p>This will remove the <code class="literal">X-Request-Foo</code> header before it is sent downstream.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_removeresponseheader_gatewayfilter_factory" href="#_removeresponseheader_gatewayfilter_factory"></a>5.10&nbsp;RemoveResponseHeader GatewayFilter Factory</h2></div></div></div><p>The RemoveResponseHeader GatewayFilter Factory takes a <code class="literal">name</code> parameter. It is the name of the header to be removed.</p><p><b>application.yml.&nbsp;</b>
+</p><p>This will remove the <code class="literal">X-Request-Foo</code> header before it is sent downstream.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_removeresponseheader_gatewayfilter_factory" href="#_removeresponseheader_gatewayfilter_factory"></a>5.11&nbsp;RemoveResponseHeader GatewayFilter Factory</h2></div></div></div><p>The RemoveResponseHeader GatewayFilter Factory takes a <code class="literal">name</code> parameter. It is the name of the header to be removed.</p><p><b>application.yml.&nbsp;</b>
 </p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">spring</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">  cloud</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">    gateway</span>:
@@ -99,7 +109,7 @@ KeyResolver userKeyResolver() {
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        uri</span>: http://example.org
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        filters</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        - RemoveResponseHeader</span>=X-Response-Foo</pre><p>
-</p><p>This will remove the <code class="literal">X-Response-Foo</code> header from the response before it is returned to the gateway client.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_rewritepath_gatewayfilter_factory" href="#_rewritepath_gatewayfilter_factory"></a>5.11&nbsp;RewritePath GatewayFilter Factory</h2></div></div></div><p>The RewritePath GatewayFilter Factory takes a path <code class="literal">regexp</code> parameter and a <code class="literal">replacement</code> parameter. This uses Java regular expressions for a flexible way to rewrite the request path.</p><p><b>application.yml.&nbsp;</b>
+</p><p>This will remove the <code class="literal">X-Response-Foo</code> header from the response before it is returned to the gateway client.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_rewritepath_gatewayfilter_factory" href="#_rewritepath_gatewayfilter_factory"></a>5.12&nbsp;RewritePath GatewayFilter Factory</h2></div></div></div><p>The RewritePath GatewayFilter Factory takes a path <code class="literal">regexp</code> parameter and a <code class="literal">replacement</code> parameter. This uses Java regular expressions for a flexible way to rewrite the request path.</p><p><b>application.yml.&nbsp;</b>
 </p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">spring</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">  cloud</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">    gateway</span>:
@@ -111,7 +121,7 @@ KeyResolver userKeyResolver() {
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        - Path</span>=/foo/**
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        filters</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        - RewritePath</span>=/foo/(?&lt;segment&gt;.*)<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">,</span> /$\{segment<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">}</span></pre><p>
-</p><p>For a request path of <code class="literal">/foo/bar</code>, this will set the path to <code class="literal">/bar</code> before making the downstream request. Notice the <code class="literal">$\</code> which is replaced with <code class="literal">$</code> because of the YAML spec.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_secureheaders_gatewayfilter_factory" href="#_secureheaders_gatewayfilter_factory"></a>5.12&nbsp;SecureHeaders GatewayFilter Factory</h2></div></div></div><p>The SecureHeaders GatewayFilter Factory adds a number of headers to the response at the reccomendation from <a class="link" href="https://blog.appcanary.com/2017/http-security-headers.html" target="_top">this blog post</a>.</p><div class="itemizedlist"><p class="title"><b>The following headers are added (allong with default values):</b></p><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><code class="literal">X-Xss-Protection:1; mode=block</code></li><li class="listitem"><code class="literal">Strict-Transport-Security:max-age=631138519</code></li><li class="listitem"><code class="literal">X-Frame-Options:DENY</code></li><li class="listitem"><code class="literal">X-Content-Type-Options:nosniff</code></li><li class="listitem"><code class="literal">Referrer-Policy:no-referrer</code></li><li class="listitem"><code class="literal">Content-Security-Policy:default-src 'self' https:; font-src 'self' https: data:; img-src 'self' https: data:; object-src 'none'; script-src https:; style-src 'self' https: 'unsafe-inline'</code></li><li class="listitem"><code class="literal">X-Download-Options:noopen</code></li><li class="listitem"><code class="literal">X-Permitted-Cross-Domain-Policies:none</code></li></ul></div><p>To change the default values set the appropriate property in the <code class="literal">spring.cloud.gateway.filter.secure-headers</code> namespace:</p><div class="itemizedlist"><p class="title"><b>Property to change:</b></p><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><code class="literal">xss-protection-header</code></li><li class="listitem"><code class="literal">strict-transport-security</code></li><li class="listitem"><code class="literal">frame-options</code></li><li class="listitem"><code class="literal">content-type-options</code></li><li class="listitem"><code class="literal">referrer-policy</code></li><li class="listitem"><code class="literal">content-security-policy</code></li><li class="listitem"><code class="literal">download-options</code></li><li class="listitem"><code class="literal">permitted-cross-domain-policies</code></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_setpath_gatewayfilter_factory" href="#_setpath_gatewayfilter_factory"></a>5.13&nbsp;SetPath GatewayFilter Factory</h2></div></div></div><p>The SetPath GatewayFilter Factory takes a path <code class="literal">template</code> parameter. It offers a simple way to manipulate the request path by allowing templated segments of the path. This uses the uri templates from Spring Framework. Multiple matching segments are allowed.</p><p><b>application.yml.&nbsp;</b>
+</p><p>For a request path of <code class="literal">/foo/bar</code>, this will set the path to <code class="literal">/bar</code> before making the downstream request. Notice the <code class="literal">$\</code> which is replaced with <code class="literal">$</code> because of the YAML spec.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_secureheaders_gatewayfilter_factory" href="#_secureheaders_gatewayfilter_factory"></a>5.13&nbsp;SecureHeaders GatewayFilter Factory</h2></div></div></div><p>The SecureHeaders GatewayFilter Factory adds a number of headers to the response at the reccomendation from <a class="link" href="https://blog.appcanary.com/2017/http-security-headers.html" target="_top">this blog post</a>.</p><div class="itemizedlist"><p class="title"><b>The following headers are added (allong with default values):</b></p><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><code class="literal">X-Xss-Protection:1; mode=block</code></li><li class="listitem"><code class="literal">Strict-Transport-Security:max-age=631138519</code></li><li class="listitem"><code class="literal">X-Frame-Options:DENY</code></li><li class="listitem"><code class="literal">X-Content-Type-Options:nosniff</code></li><li class="listitem"><code class="literal">Referrer-Policy:no-referrer</code></li><li class="listitem"><code class="literal">Content-Security-Policy:default-src 'self' https:; font-src 'self' https: data:; img-src 'self' https: data:; object-src 'none'; script-src https:; style-src 'self' https: 'unsafe-inline'</code></li><li class="listitem"><code class="literal">X-Download-Options:noopen</code></li><li class="listitem"><code class="literal">X-Permitted-Cross-Domain-Policies:none</code></li></ul></div><p>To change the default values set the appropriate property in the <code class="literal">spring.cloud.gateway.filter.secure-headers</code> namespace:</p><div class="itemizedlist"><p class="title"><b>Property to change:</b></p><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><code class="literal">xss-protection-header</code></li><li class="listitem"><code class="literal">strict-transport-security</code></li><li class="listitem"><code class="literal">frame-options</code></li><li class="listitem"><code class="literal">content-type-options</code></li><li class="listitem"><code class="literal">referrer-policy</code></li><li class="listitem"><code class="literal">content-security-policy</code></li><li class="listitem"><code class="literal">download-options</code></li><li class="listitem"><code class="literal">permitted-cross-domain-policies</code></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_setpath_gatewayfilter_factory" href="#_setpath_gatewayfilter_factory"></a>5.14&nbsp;SetPath GatewayFilter Factory</h2></div></div></div><p>The SetPath GatewayFilter Factory takes a path <code class="literal">template</code> parameter. It offers a simple way to manipulate the request path by allowing templated segments of the path. This uses the uri templates from Spring Framework. Multiple matching segments are allowed.</p><p><b>application.yml.&nbsp;</b>
 </p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">spring</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">  cloud</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">    gateway</span>:
@@ -123,7 +133,7 @@ KeyResolver userKeyResolver() {
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        - Path</span>=/foo/{segment<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">}</span>
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        filters</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        - SetPath</span>=/{segment<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">}</span></pre><p>
-</p><p>For a request path of <code class="literal">/foo/bar</code>, this will set the path to <code class="literal">/bar</code> before making the downstream request.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_setresponseheader_gatewayfilter_factory" href="#_setresponseheader_gatewayfilter_factory"></a>5.14&nbsp;SetResponseHeader GatewayFilter Factory</h2></div></div></div><p>The SetResponseHeader GatewayFilter Factory takes <code class="literal">name</code> and <code class="literal">value</code> parameters.</p><p><b>application.yml.&nbsp;</b>
+</p><p>For a request path of <code class="literal">/foo/bar</code>, this will set the path to <code class="literal">/bar</code> before making the downstream request.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_setresponseheader_gatewayfilter_factory" href="#_setresponseheader_gatewayfilter_factory"></a>5.15&nbsp;SetResponseHeader GatewayFilter Factory</h2></div></div></div><p>The SetResponseHeader GatewayFilter Factory takes <code class="literal">name</code> and <code class="literal">value</code> parameters.</p><p><b>application.yml.&nbsp;</b>
 </p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">spring</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">  cloud</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">    gateway</span>:
@@ -133,7 +143,7 @@ KeyResolver userKeyResolver() {
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        uri</span>: http://example.org
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        filters</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">        - SetResponseHeader</span>=X-Response-Foo<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">,</span> Bar</pre><p>
-</p><p>This GatewayFilter replaces all headers with the given name, rather than adding. So if the downstream server responded with a <code class="literal">X-Response-Foo:1234</code>, this would be replaced with <code class="literal">X-Response-Foo:Bar</code>, which is what the gateway client would receive.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_setstatus_gatewayfilter_factory" href="#_setstatus_gatewayfilter_factory"></a>5.15&nbsp;SetStatus GatewayFilter Factory</h2></div></div></div><p>The SetStatus GatewayFilter Factory takes a single <code class="literal">status</code> parameter. It must be a valid Spring <code class="literal">HttpStatus</code>. It may be the integer value <code class="literal">404</code> or the string representation of the enumeration <code class="literal">NOT_FOUND</code>.</p><p><b>application.yml.&nbsp;</b>
+</p><p>This GatewayFilter replaces all headers with the given name, rather than adding. So if the downstream server responded with a <code class="literal">X-Response-Foo:1234</code>, this would be replaced with <code class="literal">X-Response-Foo:Bar</code>, which is what the gateway client would receive.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="_setstatus_gatewayfilter_factory" href="#_setstatus_gatewayfilter_factory"></a>5.16&nbsp;SetStatus GatewayFilter Factory</h2></div></div></div><p>The SetStatus GatewayFilter Factory takes a single <code class="literal">status</code> parameter. It must be a valid Spring <code class="literal">HttpStatus</code>. It may be the integer value <code class="literal">404</code> or the string representation of the enumeration <code class="literal">NOT_FOUND</code>.</p><p><b>application.yml.&nbsp;</b>
 </p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">spring</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">  cloud</span>:
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-attribute">    gateway</span>:

spring-cloud-gateway.xml

@@ -352,6 +352,25 @@ for details on setting up your build system with the current Spring Cloud Releas
 </formalpara>
 <simpara>This will prefix <literal>/mypath</literal> to the path of all matching requests. So a request to <literal>/hello</literal>, would be sent to <literal>/mypath/hello</literal>.</simpara>
 </section>
+<section xml:id="_preservehostheader_gatewayfilter_factory">
+<title>PreserveHostHeader GatewayFilter Factory</title>
+<simpara>The PreserveHostHeader GatewayFilter Factory has not parameters. This filter, sets a request attribute that the routing filter will inspect to determine if the original host header should be sent, rather than the host header determined by the http client.</simpara>
+<formalpara>
+<title>application.yml</title>
+<para>
+<programlisting language="yaml" linenumbering="unnumbered">spring:
+  cloud:
+    gateway:
+      routes:
+      # =====================================
+      - id: preserve_host_route
+        uri: http://example.org
+        filters:
+        - PreserveHostHeader</programlisting>
+</para>
+</formalpara>
+<simpara>This will prefix <literal>/mypath</literal> to the path of all matching requests. So a request to <literal>/hello</literal>, would be sent to <literal>/mypath/hello</literal>.</simpara>
+</section>
 <section xml:id="_requestratelimiter_gatewayfilter_factory">
 <title>RequestRateLimiter GatewayFilter Factory</title>
 <simpara>The RequestRateLimiter GatewayFilter Factory takes three parameters: <literal>replenishRate</literal>, <literal>burstCapacity</literal> &amp; <literal>keyResolverName</literal>.</simpara>