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

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	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	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

Parameter		Description
If (Matching All Conditions)	Path is 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: Specifies the domain name to which requests are rewritten. If you leave this parameter empty, the original domain name is retained. Path: Specifies the path to which requests are rewritten. If you leave this parameter empty, the original path is retained. For more information about path enhancement, see the Configure paths for rewrites and redirects section. Search: Specifies the query string to which requests are rewritten. If you leave this parameter empty, the original query string is retained.
Then	Forward	Select a virtual endpoint group from the drop-down list.

Example 2: Configure a forwarding rule whose action is Redirect

Parameter		Description
If (Matching All Conditions)	Path is 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	Redirect	Protocol: Specifies the protocol for redirection. Valid values: HTTP and HTTPS. If you leave this parameter empty, the default value HTTP is used. Domain Name: Specifies the domain name for redirection. If you leave this parameter empty, the original domain name is retained. Port: Specifies the port for redirection. If you leave this parameter empty, the default value is 80 for HTTP listeners and 443 for HTTPS listeners. Path: Specifies the path for redirection. If you leave this parameter empty, the original path is retained. For more information about path enhancement, see the Configure paths for rewrites and redirects section. Search: Specifies the query string for redirection. If you leave this parameter empty, the original query string is retained. Status Code: `301`