How to configure domain name-based and path-based forwarding rules - Global Accelerator

Global Accelerator (GA) listeners support domain name-based and path-based forwarding rules. This topic describes how to configure domain name-based and path-based forwarding conditions. This topic also describes how to configure paths for rewrites and redirects.

Configure domain names in forwarding conditions

You can specify a specific domain name, a wildcard domain name, or a regular expression as the forwarding condition in a domain name-based forwarding rule. For more information about how to add a forwarding rule, see Add a forwarding rule.

Match type	Description
Exact match and wildcard match	Match conditions Exact match: The requested domain name must be the same as the specified domain name. Wildcard match: The requested domain name must match the wildcard pattern of the specified domain name. Requirements The domain name must be 3 to 128 characters in length and can contain only letters, digits, `hyphens (-), and periods (.)`. You can use asterisks (``) and question marks (`?`) as wildcard characters. Examples* Requested domain name: www.example.com Exact match: matches only if `www.example.com` is specified in the forwarding rule. Wildcard match: matches if `.example.com` or `www.example.` is specified in the forwarding rule.
Regular expression match (case-insensitive)	Match conditions The requested domain name must match the specified regular expression. Requirements The domain name must be 3 to 128 characters in length and can contain only letters, digits, and the following special characters: `. - ? = ~ _ + / \ ^ * ! $ & \| ( ) [ ]` Examples Requested domain name: www.Example.com Matches if `^www.example.com$` is specified in the forwarding rule.

Configure paths in forwarding conditions

You can specify a specific path, a wildcard path, or a regular expression as the match condition in a path-based forwarding rule. For more information about how to add a forwarding rule, see Add a forwarding rule.

Match type	Description
Exact match and wildcard match	Match conditions Exact match: The requested path must be the same as the specified path. Wildcard match: The requested path must match the wildcard pattern of the specified path. Requirements The path must be 1 to 128 characters in length and must start with a hyphen (`/`). The path can contain only letters, digits, and the following special characters: `$ - _ . + / & ~ @ : '`. You can use asterisks (``) and question marks (`?`) as wildcard characters. Examples* Requested path: /example/text Exact match: matches only if `/example/text` is specified in the forwarding rule. Wildcard match: matches if `/example/` is specified in the forwarding rule. Note* The path matching rules of Global Accelerator are different from the rules of NGINX. Global Accelerator does not support the longest prefix match rule. For example, a common path configured for NGINX is `location /abc`. The longest prefix match rule is used to match the path. To perform longest prefix match, Global Accelerator uses wildcard characters. You can configure `/abc/*` in Global Accelerator to perform longest prefix match.
Regular expression match (case-sensitive)	Match conditions The requested path matches the specified regular expression. Requirements The regular expression can contain letters, digits, and the following special characters: `. - _ / \ = ? ~ ^ * $ : ( ) [ ] + \| " ' @` Examples Requested path: `/sys/aaa/HOST` Matches if `^/sys/(.*)/HOST$` is specified in the forwarding rule.

Configure paths for rewrites and redirects

If you specify a regular expression as the match condition in a rewrite or redirect rule, the regular expression is overwritten by the path to which requests are redirected or rewritten. For more information about how to add a forwarding rule, see Add a forwarding rule.

Note

For more information about how to configure regular expressions in path-based forwarding conditions, see the Configure paths in forwarding conditions section of this topic.

Precautions
- The number of capture groups, defined by parentheses (( )), must be the same as the number of variables, defined by dollar signs ($), in the path to which requests are rewritten or redirected.
- You can use up to three variables (${1}, ${2}, and ${3}) to form the path that overwrites the original path. The variables cannot be replaced with other characters.

Procedure

Path matching: The client sends a request and matches the regular expression in a path-based forwarding rule.
Extraction and replacement: The content extracted from the capture groups, defined by parentheses (( )), are written to ${1}, ${2}, and ${3}. The content is used in the path to which requests are rewritten or redirected.
Concatenation: The variables ${1}, ${2}, and ${3} are replaced with actual values. The values are concatenated to form the actual path.

No.	Step	Example
1	Configure the forwarding condition and forwarding action in the forwarding rule.	Path in forwarding condition: `/sys/(.)/(.)/aaa` Path to which requests are rewritten or redirected: `/${1}/${2}`
2	A client request matches the path in a forwarding rule.	Requested path: `/sys/ccc/bbb/aaa` Matched path: `/sys/(.)/(.)/aaa`
3	The system extracts values from the regular expression and replaces the variables with the values.	`ccc` and `bbb` are extracted from `(.*)` in the regular expression and replace the variables ${1} and ${2} in the path to which requests are rewritten or redirected. `${1}` is replaced by `ccc`. `${2}` is replaced by `bbb`.
4	The values are concatenated to form the actual path.	The path received by the backend server is `/ccc/bbb`.

Examples

You can create forwarding rules in the GA console based on the preceding usage notes and procedure The following examples show how to configure forwarding rules.

Example 1: Configure a rule whose actions are Rewrite and Forward

路径-重写示例png.png

Parameter		Description
If (Matching All Conditions)	Path: Regular Expression Match(Case-sensitive)	Match conditions The requested path matches the specified regular expression. Requirements The regular expression can contain letters, digits, and the following special characters: `. - _ / \ = ? ~ ^ * $ : ( ) [ ] + \| " ' @` Examples Requested path: `/sys/ccc/bbb/aaa` The requested path is matched if `/sys/(.)/(.)/aaa` is specified as the forwarding condition.
Then	Rewrite	Domain Name: `${host}` Path: `/${1}/${2}` Search: `${query}`
Then	Forward	Select a virtual endpoint group from the drop-down list.

Example 2: Configure a forwarding rule whose action is Redirect

路径-重定向示例 .png

Parameter		Description
If (Matching All Conditions)	Path: Regular Expression Matching (Case-sensitive)	Match conditions The requested path matches the specified regular expression. Requirements The regular expression can contain letters, digits, and the following special characters: `. - _ / \ = ? ~ ^ * $ : ( ) [ ] + \| " ' @` Examples Requested path: `/sys/ccc/bbb/aaa` The requested path is matched if `/sys/(.)/(.)/aaa` is specified as the forwarding condition.
Then	Redirect	Protocol: `$protocol` Hosts: `${host}` Port: `${port}` Path: `/${1}/${2}` Search: `${query}` Status Code: `301`