HttpHeadersFilters (HTTP header filter) will be applied to the request before sending it to the downstream service, such as in NettyRoutingFilter.
Introduction
HttpHeadersFilters (HTTP header filter) is a component that processes and converts the header information of the request before the gateway routes the request to the downstream service. These filters allow developers to modify, add or delete request headers to meet specific needs and business scenarios.
In a distributed system, a gateway plays an important role in receiving requests from clients and routing them to the appropriate downstream services. In this process, the header information plays a key role, including metadata and control information related to the request. However, sometimes it is necessary to customize the header information to meet specific requirements or follow some standard specifications.
HttpHeadersFilters provide a flexible and customizable way to process request headers. By defining and configuring different filters, various operations on the request header can be realized. Here are some common functions and uses of HttpHeadersFilters:
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Adding header information: Filters can be used to add additional header information to the request, such as authentication credentials, security tokens, tracking identifiers, etc. This information can help downstream services authenticate, authorize, or track the processing flow of requests.
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Modify header information: Sometimes it is necessary to modify some fields of the request header, such as changing the source address of the request, modifying the content type, setting cache control, etc. Filters can be used to modify the specified header field to ensure that the request is correctly processed by the downstream service.
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Remove header information: In some cases, it may be necessary to remove specific header fields from the request. For example, removing sensitive information, removing irrelevant header fields, or following certain protocol specifications. HttpHeadersFilters provides the function of removing specified header fields to ensure that the header information of the request is as expected.
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Conversion of header information: Sometimes it is necessary to convert the format of the request header to adapt to the following