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本文主要研究spring cloud gateway的XForwardedHeadersFilter
GatewayAutoConfiguration
spring-cloud-gateway-core-2.0.0.RC1-sources.jar!/org/springframework/cloud/gateway/config/GatewayAutoConfiguration.java
@Configuration
@ConditionalOnProperty(name = "spring.cloud.gateway.enabled", matchIfMissing = true)
@EnableConfigurationProperties
@AutoConfigureBefore(HttpHandlerAutoConfiguration.class)
@AutoConfigureAfter({GatewayLoadBalancerClientAutoConfiguration.class, GatewayClassPathWarningAutoConfiguration.class})
@ConditionalOnClass(DispatcherHandler.class)
public class GatewayAutoConfiguration {
//......
@Bean
@ConditionalOnProperty(name = "spring.cloud.gateway.x-forwarded.enabled", matchIfMissing = true)
public XForwardedHeadersFilter xForwardedHeadersFilter() {
return new XForwardedHeadersFilter();
}
//......
}
默认注册了XForwardedHeadersFilter
XForwardedHeadersFilter
spring-cloud-gateway-core-2.0.0.RC1-sources.jar!/org/springframework/cloud/gateway/filter/headers/XForwardedHeadersFilter.java
@ConfigurationProperties("spring.cloud.gateway.x-forwarded")
public class XForwardedHeadersFilter implements HttpHeadersFilter, Ordered {
//......
@Override
public HttpHeaders filter(HttpHeaders input, ServerWebExchange exchange) {
ServerHttpRequest request = exchange.getRequest();
HttpHeaders original = input;
HttpHeaders updated = new HttpHeaders();
original.entrySet().stream()
.forEach(entry -> updated.addAll(entry.getKey(), entry.getValue()));
if (isForEnabled()) {
String remoteAddr = request.getRemoteAddress().getAddress().getHostAddress();
List<String> xforwarded = original.get(X_FORWARDED_FOR_HEADER);
// prevent duplicates
if (remoteAddr != null &&
(xforwarded == null || !xforwarded.contains(remoteAddr))) {
write(updated, X_FORWARDED_FOR_HEADER, remoteAddr, isForAppend());
}
}
String proto = request.getURI().getScheme();
if (isProtoEnabled()) {
write(updated, X_FORWARDED_PROTO_HEADER, proto, isProtoAppend());
}
if (isPortEnabled()) {
String port = String.valueOf(request.getURI().getPort());
if (request.getURI().getPort() < 0) {
port = String.valueOf(getDefaultPort(proto));
}
write(updated, X_FORWARDED_PORT_HEADER, port, isPortAppend());
}
if (isHostEnabled()) {
String host = toHostHeader(request);
write(updated, X_FORWARDED_HOST_HEADER, host, isHostAppend());
}
return updated;
}
//......
}
- 如果spring.cloud.gateway.x-forwarded.for-enabled为true，则会写入X-Forwarded-For
- 如果spring.cloud.gateway.x-forwarded.proto-enabled为true，则会写入X-Forwarded-Proto
- 如果spring.cloud.gateway.x-forwarded.port-enabled为true，则会写入X-Forwarded-Port
- 如果spring.cloud.gateway.x-forwarded.host-enabled为true，则会写入X-Forwarded-Host
每个enable属性都有一个append属性，用来决定是否是添加还是追加
private void write(HttpHeaders headers, String name, String value, boolean append) {
if (append) {
headers.add(name, value);
// these headers should be treated as a single comma separated header
List<String> values = headers.get(name);
String delimitedValue = StringUtils.collectionToCommaDelimitedString(values);
headers.set(name, delimitedValue);
} else {
headers.set(name, value);
}
}
如果是append，则逗号分隔写入headers，如果不是则是采取set操作。
配置
{
"sourceType": "org.springframework.cloud.gateway.filter.headers.XForwardedHeadersFilter",
"defaultValue": true,
"name": "spring.cloud.gateway.x-forwarded.enabled",
"description": "If the XForwardedHeadersFilter is enabled.",
"type": "java.lang.Boolean"
},
{
"sourceType": "org.springframework.cloud.gateway.filter.headers.XForwardedHeadersFilter",
"defaultValue": true,
"name": "spring.cloud.gateway.x-forwarded.for-append",
"description": "If appending X-Forwarded-For as a list is enabled.",
"type": "java.lang.Boolean"
},
{
"sourceType": "org.springframework.cloud.gateway.filter.headers.XForwardedHeadersFilter",
"defaultValue": true,
"name": "spring.cloud.gateway.x-forwarded.for-enabled",
"description": "If X-Forwarded-For is enabled.",
"type": "java.lang.Boolean"
},
{
"sourceType": "org.springframework.cloud.gateway.filter.headers.XForwardedHeadersFilter",
"defaultValue": true,
"name": "spring.cloud.gateway.x-forwarded.host-append",
"description": "If appending X-Forwarded-Host as a list is enabled.",
"type": "java.lang.Boolean"
},
{
"sourceType": "org.springframework.cloud.gateway.filter.headers.XForwardedHeadersFilter",
"defaultValue": true,
"name": "spring.cloud.gateway.x-forwarded.host-enabled",
"description": "If X-Forwarded-Host is enabled.",
"type": "java.lang.Boolean"
},
{
"sourceType": "org.springframework.cloud.gateway.filter.headers.XForwardedHeadersFilter",
"defaultValue": 0,
"name": "spring.cloud.gateway.x-forwarded.order",
"description": "The order of the XForwardedHeadersFilter.",
"type": "java.lang.Integer"
},
{
"sourceType": "org.springframework.cloud.gateway.filter.headers.XForwardedHeadersFilter",
"defaultValue": true,
"name": "spring.cloud.gateway.x-forwarded.port-append",
"description": "If appending X-Forwarded-Port as a list is enabled.",
"type": "java.lang.Boolean"
},
{
"sourceType": "org.springframework.cloud.gateway.filter.headers.XForwardedHeadersFilter",
"defaultValue": true,
"name": "spring.cloud.gateway.x-forwarded.port-enabled",
"description": "If X-Forwarded-Port is enabled.",
"type": "java.lang.Boolean"
},
{
"sourceType": "org.springframework.cloud.gateway.filter.headers.XForwardedHeadersFilter",
"defaultValue": true,
"name": "spring.cloud.gateway.x-forwarded.proto-append",
"description": "If appending X-Forwarded-Proto as a list is enabled.",
"type": "java.lang.Boolean"
},
{
"sourceType": "org.springframework.cloud.gateway.filter.headers.XForwardedHeadersFilter",
"defaultValue": true,
"name": "spring.cloud.gateway.x-forwarded.proto-enabled",
"description": "If X-Forwarded-Proto is enabled.",
"type": "java.lang.Boolean"
}
小结
spring cloud gateway提供了XForwardedHeadersFilter，用来决定进行路由转发的时候转发哪些X-Forwarded相关的header，同时提供append选项，用来控制是否是追加还是覆盖到header中。
