diff --git a/docs/root/configuration/http/http_filters/cdn_loop_filter.rst b/docs/root/configuration/http/http_filters/cdn_loop_filter.rst index 5b81d1be2522..400f462f68c1 100644 --- a/docs/root/configuration/http/http_filters/cdn_loop_filter.rst +++ b/docs/root/configuration/http/http_filters/cdn_loop_filter.rst @@ -1,56 +1,49 @@ .. _config_http_filters_cdn_loop: -CDN-Loop header +CDN-Loop 头部 =============== -The CDN-Loop header filter participates in the cross-CDN loop detection protocol specified by `RFC -8586 `_. The CDN-Loop header filter performs two actions. -First, the filter checks to see how many times a particular CDN identifier has appeared in the -CDN-Loop header. Next, if the check passes, the filter then appends the CDN identifier to the -CDN-Loop header and passes the request to the next upstream filter. If the check fails, the filter -stops processing on the request and returns an error response. +CDN-Loop 头部过滤器参与 `RFC 8586 `_ 定义的 cross-CDN 循环检测协议。 +CDN-Loop 头部过滤器有两个作用。首先，过滤器会检测 CDN-Loop 头部中特定的 CDN 标识出现过的次数。 +其次，在通过第一步校验后，过滤器会在 CDN-Loop 头部中追加一个 CDN 标识，然后将请求传递给下游过滤器。如果校验失败， +过滤器会终止该请求的处理并返回一个包含错误信息的响应。 -RFC 8586 is particular in how the CDN-Loop header should be modified. As such: +RFC 8586 在如何修改 CDN-Loop 头部方面有特别的规定。例如： -* other filters in the filter chain should not modify the CDN-Loop header and -* the HTTP route configuration's :ref:`request_headers_to_add - ` or - :ref:`request_headers_to_remove - ` fields should - not contain the CDN-Loop header. +* 在过滤器链路上的的其他过滤器不能修改 CDN-Loop 头部，且 +* HTTP 路由配置的 :ref:`请求头部增加 + ` + 或 :ref:`请求头部删除 ` + 应不包含 CDN-Loop 头部。 -The filter will coalesce multiple CDN-Loop headers into a single, comma-separated header. +过滤器会将多个 CDN-Loop 头部合并成一个，以逗号分隔。 -Configuration +配置 ------------- -The filter is configured with the name *envoy.filters.http.cdn_loop*. +此过滤器的名称应该被配置为 *envoy.filters.http.cdn_loop* 。 -The `filter config `_ has two fields. +`过滤器配置 `_ 有两个字段。 -* The *cdn_id* field sets the identifier that the filter will look for within and append to the - CDN-Loop header. RFC 8586 calls this field the "cdn-id"; "cdn-id" can either be a pseudonym or a - hostname the CDN provider has control of. The *cdn_id* field must not be empty. -* The *max_allowed_occurrences* field controls how many times *cdn_id* can appear in the CDN-Loop - header on downstream requests (before the filter appends *cdn_id* to the header). If the *cdn_id* - appears more than *max_allowed_occurrences* times in the header, the filter will reject the - downstream's request. Most users should configure *max_allowed_occurrences* to be 0 (the - default). +* *cdn_id* 字段设置过滤器查找和追加在 CDN-Loop 头部中的标识； RFC 8586 称该字段为 "cdn-id"; + "cdn-id" 可以是 CDN 提供的、可控的化名或主机名。*cdn_id* 字段必须非空。 -Response Code Details +* *max_allowed_occurrences* 字段控制下游请求 CDN-Loop 头部中 *cdn_id* 可以出现的次数。 + （在过滤器追加 *cdn_id* 到头部前） 如果头部中 *cdn_id* 出现的次数大于 *max_allowed_occurrences*， + 过滤器将拒绝此次下游请求。大多数用户应将 *max_allowed_occurrences* 设置为 0 （默认值）。 + +响应码详情 --------------------- .. list-table:: :header-rows: 1 - * - Name - - HTTP Status - - Description + * - 名称 + - HTTP 状态 + - 描述 * - invalid_cdn_loop_header - - 400 (Bad Request) - - The CDN-Loop header in the downstream is invalid or unparseable. + - 400 （错误的请求） + - 下游系统的 CDN-Loop 头部无效或无法转义。 * - cdn_loop_detected - - 502 (Bad Gateway) - - The *cdn_id* value appears more than *max_allowed_occurrences* in the CDN-Loop header, - indicating a loop between CDNs. - + - 502 （错误网关） + - CDN-Loop 头部中 *cdn_id* 的值超过了 *max_allowed_occurrences*，说明在 CDN 中存在循环。 \ No newline at end of file