ApsaraVideo VOD:Configure HTTP request headers

Notes

• An outgoing request is an HTTP message that is sent from CDN to an origin server. Modifying the outgoing request header configuration affects only HTTP messages that are sent from CDN to an origin server. This configuration does not affect HTTP messages that are served directly from CDN POPs to users.

• You cannot modify outgoing request headers for a wildcard domain name.

• ApsaraVideo VOD forwards the following back-to-origin HTTP request headers by default. No additional configuration is required.

  Origin HTTP header	Description	Example
  Ali-Cdn-Real-Ip	The real IP address of the client connecting to a CDN or POP.	Ali-Cdn-Real-Ip:192.168.0.1
  X-Forwarded-For	The IP addresses of the client and all intermediate CDN or POPs in the path of the origin request.	X-Forwarded-For:192.168.0.1, 172.16.0.1
  X-Client-Scheme	The application-layer protocol, such as HTTP or HTTPS, that a client uses to send a request to a CDN or POP.	X-Client-Scheme:http
  Host	The domain name of the origin website that is accessed by the origin request.	Host:example.com
  Via	The names of all CDN or POPs that the client request passes through.	Via:cn2546-10.l1, cache1.cn2546-10, l2cn2547-7.l2, cache1.l2cn2547-7

Procedure

1. Log on to the ApsaraVideo VOD console.

2. In the left-side navigation pane, choose Configuration Management > CDN Configuration > Domain Names.

3. Find the desired domain name and click Configure in the Actions column.

4. In the domain's left-side navigation pane, click Back-to-Origin.

5. Click the Back-to-origin HTTP Request Header tab.

6. Click Add and configure the header settings.

   Important

   If you configure different operations for the same origin request header, a conflict occurs, and the highest-priority operation is executed. The priority order is: Replace > Add > Change and Delete.

   Add header

   Parameter	Example	Description
   Operation	Add	Adds the specified request header to origin requests.
   Request Header	Custom Origin Request Header	Select Custom Back-to-origin Request Headers or a preset request header.
   Header Name	x-code	Specifies the custom request header name as x-code.
   Header Value	key1, key2	You can configure multiple values for a request header. Separate multiple values with a comma (,).
   Allow Duplicates	Yes	Yes: Allows duplicate request headers to be added. For example, x-code:key1 and x-code:key2. No: If you add a header with the same name, the new value overwrites the existing one. For example, if you first add x-code:key1 and then add x-code:key2, the final value is x-code:key2.
   Rule Condition	Do not use	Rule conditions identify various parameters in user requests to determine whether a configuration applies to a specific request. Important When you use a rule condition, matching is based on the priority of the associated rule condition, not the configuration order of the feature itself. Do not use: No rule condition is used. To add or edit a rule condition, go to the rules engine.

   Delete header

   Parameter	Example	Description
   Operation	Delete	Deletes all headers that match the specified name, including duplicates.
   Request Header	Custom Origin Request Header	Select Custom Back-to-origin Request Headers or a preset request header.
   Header Name	x-code	Specifies the custom request header name as x-code.
   Rule Condition	Do not use	A rule condition allows a rule to be applied only when a request meets specific criteria. Do not use: Disables conditional rules. You can add or edit conditional rules in the Rules engine.

   Change header

   Parameter	Example	Description
   Operation	Change	Changes a header's value. This operation is not allowed if duplicate headers with the same name exist.
   Request Header	Custom Origin Request Header	Select Custom Back-to-origin Request Headers or a preset request header.
   Header Name	x-code	Specifies the custom request header name as x-code.
   Change Value To	key1, key3	You can configure multiple values for a request header. Separate multiple values with a comma (,).
   Rule Condition	Do not use	A rule condition allows a rule to be applied only when a request meets specific criteria. Do not use: Disables conditional rules. You can add or edit conditional rules in the Rules engine.

   Replace header

   Parameter	Example	Description
   Operation	Replace	Replaces a header's value. This operation is not allowed if duplicate headers with the same name exist.
   Request Header	Custom Origin Request Header	Select Custom Back-to-origin Request Headers or a preset request header.
   Header Name	x-code	Specifies the custom request header name as x-code.
   Find	key	A regular expression to find the value to replace.
   Replace With	abc	The replacement value.
   Match	Match All	Match All: Replaces all matched values. For example, for the header x-code:key1,key2,key3, if you use a regular expression to match "key" and replace it with "abc", the result is x-code:abc1,abc2,abc3. Match the First Only: Replaces only the first matched value. For example, for the header x-code:key1,key2,key3, if you use a regular expression to match "key" and replace it with "abc", the result is x-code:abc1,key2,key3.
   Rule Condition	Do not use	A rule condition allows a rule to be applied only when a request meets specific criteria. Do not use: Disables conditional rules. You can add or edit conditional rules in the Rules engine.

7. Click OK to complete the configuration.

Examples

Example 1

Scenario: Add the X-Forwarded-For header to back-to-origin requests to pass the client IP and intermediate proxy server IPs to the origin server.

ApsaraVideo VOD includes the X-Forwarded-For header in back-to-origin requests by default. No configuration is needed unless you want to change the header name.

• Custom request header name: X-Forwarded-For.

• Request header value: $proxy_add_x_forwarded_for.

Example 2

Scenario: Add a header to back-to-origin requests to pass the real client IP address to the origin server.

ApsaraVideo VOD includes the Ali-Cdn-Real-Ip header in back-to-origin requests by default. This header contains the real client IP address. No configuration is needed unless you want to change the header name.

Example 3

Scenario: Add a header to back-to-origin requests to pass the client's real port to the origin server.

ApsaraVideo VOD includes the Ali-Cdn-Real-Port header in back-to-origin requests by default. This header contains the real client port. No configuration is needed unless you want to change the header name.

Related documents

Configure domain names in batches