If you want to rewrite the HTTP headers in a back-to-origin request URL, you can customize HTTP request headers in the Alibaba Cloud Content Delivery Network (CDN) console. This topic describes how to customize an HTTP request header.

Background information

HTTP headers are components of the header section of request and response messages that are transmitted over HTTP.

HTTP headers include general headers, request headers, and response headers.

Customize an HTTP request header
Note
  • A back-to-origin request is an HTTP message that is transmitted by Alibaba Cloud CDN to an origin server of a specific accelerated domain name.
  • Custom HTTP request headers are used only in the back-to-origin requests that are sent to the origin server. The back-to-origin settings do not change the HTTP responses from Alibaba Cloud CDN to end clients.
  • Custom HTTP request headers do not support wildcard domain names.

Procedure

  1. Log on to the Alibaba Cloud CDN console.
  2. In the left-side navigation pane, click Domain Names.
  3. On the Domain Names page, find the domain name that you want to manage and click Manage in the Actions column of the domain name.
  4. In the management pane of the domain name, click Back-to-origin.
  5. Click Custom Request Headers (New).
  6. On the Custom Request Headers (New) tab, click Customize.
  7. Set the parameters in the Back-to-origin Request Headers dialog box.
    Notice If different operations are performed on the same request header at the same time, these operations have different priorities. The operations are prioritized in the following order: Replace > Add > Change or Delete. For example, if you perform the Add and Delete operations on the same request header at the same time, the request header is added and then deleted.
    • Parameters of the Add operationCustomize an HTTP request header
      Parameter Example Description
      Operation Add Adds a specific request header to the back-to-origin HTTP request.
      Request Header Custom Back-to-origin Request Headers You can use the default value, or select Custom Request Header from the Request Header drop-down list to add a custom request header.
      Header Name x-code Adds a custom request header named x-code.
      Header Value key1 You can specify one or more values for a request header. Separate multiple values with commas (,).
      key1, key2
      Allow Duplicates Yes If Allow Duplicates is set to Yes, you can add duplicate request headers. For example, x-code:key1 and x-code:key2 can coexist.
      No If Allow Duplicates is set to No, the new header value overwrites the existing one that uses the same header name. For example, if you add x-code:key1 and then add x-code:key2, the final header name-value pair is x-code:key2.
    • Parameters of the Delete operationDelete
      Parameter Example Description
      Operation Delete Deletes all request headers that match the values of the Request Header and Header Name parameters. Duplicate request headers are also deleted.
      Request Header Custom Back-to-origin Request Headers You can use the default value, or select Custom Request Header from the Request Header drop-down list to delete custom request headers.
      Header Name x-code Deletes custom request headers named x-code.
    • Parameters of the Change operationChange
      Parameter Example Description
      Operation Change You can perform the Change operation only if no duplicate request header exists.
      Request Header Custom Back-to-origin Request Headers You can use the default value, or select Custom Request Header from the Request Header drop-down list to change a custom request header.
      Header Name x-code Changes the custom request header named x-code.
      Change Value To key1, key3 You can specify one or more values for a request header. Separate multiple values with commas (,).
    • Parameters of the Replace operationReplace
      Parameter Example Description
      Operation Replace You can perform the Replace operation only if no duplicate request header exists.
      Request Header Custom Back-to-origin Request Headers You can use the default value, or select Custom Request Header from the Request Header drop-down list to replace a custom request header.
      Header Name x-code Replaces the custom request header named x-code.
      Find key Allows you to use regular expressions to search for the value that you want to replace.
      Replace With abc Allows you to use regular expressions to replace matching values.
      Match Match All If Match is set to Match All, all matching values will be replaced. For example, if you use a regular expression to replace all the "key" in x-code:key1,key2,key3 with "abc", the name-value pair is changed tox-code:abc1,abc2,abc3.
      Match the First Only If Match is set to Match the First Only, only the first matching value will be replaced. For example, if you use a regular expression to replace the first "key" in x-code:key1,key2,key3 with "abc", the name-value pair is changed to x-code:abc1,key2,key3.
  8. Click OK.