The ngx_http_server_redirect_module is a custom nginx module designed to facilitate dynamic server redirection based on configurable rules. It allows users to redirect incoming requests to different servers conditionally.
This Nginx module is currently considered experimental. Issues and PRs are welcome if you encounter any problems.
To use theses modules, configure your nginx branch with --add-module=/path/to/ngx_http_server_redirect_module.
To enable named conditions, build ngx_condition_module and this module statically in the same nginx configuration.
Conditional syntax is selected at compile time:
- With
ngx_condition_module, use namedconditionexpressions and placeserver_redirectinside a server-levelwhenblock.if=andif!=parameters are rejected. - Without
ngx_condition_module,whenis unavailable and legacyif=/if!=parameters remain supported.if=matches a non-empty value other than"0";if!=matches an empty value or"0".
If a condition does not match, that redirect rule is skipped and the next rule can be evaluated.
Redirect all requests to newserver.com unconditionally.
http {
server {
listen 80;
server_name example.com;
server_redirect newserver.com;
location / {
proxy_pass http://newserver.com;
}
}
server {
listen 80;
server_name newserver.com;
# You can get original host from this variable.
add_header x-original-host $server_redirect_original_host;
location / {
proxy_pass http://upstream.com;
}
}
}Redirect requests based on the presence of a specific header.
http {
server {
listen 80;
server_name example.com;
# With ngx_condition_module.
condition redirect_enabled is_not_empty $http_x_redirect;
when redirect_enabled {
server_redirect newserver.com;
}
# Without ngx_condition_module, use this instead:
# server_redirect newserver.com if=$http_x_redirect;
# This module takes effect after the real_ip module,
# Therefore, the real_ip module's directives will take effect on the server before server redirect.
# real_ip_header x-client-ip;
location / {
proxy_pass http://newserver.com;
}
}
server {
listen 80;
server_name newserver.com;
# You can get original host from this variable.
add_header x-original-host $server_redirect_original_host;
location / {
proxy_pass http://upstream.com;
}
}
}Redirect the current request to another server from the first request path.
If request http://example.com/newserver.com/test?arg=1, it will be redirect to http:///newserver.com/test?arg=1. This process is internal and no 302 redirection will occur.
http {
server {
listen 80;
server_name example.com;
# Enable schedule redirection.
schedule_redirect on;
# Requests will not arrive here unless the first path in the request path does not exist or the host in the first path is invalid.
return 400 "request path invalid";
}
server {
listen 80;
server_name newserver.com;
# You can get original host from this variable.
add_header x-original-host $server_redirect_original_host;
location / {
proxy_pass http://upstream.com;
}
}
}Syntax: server_redirect target_host;
Default: -
Context: server, server when
Redirect the current request to another server. The target server must have the same listening port as the current server.
The target_host value should be a specific host name just like the host in the request header. Even if the target server you want to redirect to is a wildcard domain or a regular expression. The target_host value can contain variables. If target_host value is empty, it will be skipped.
If the target server cannot be found, the request will be redirected to the default server.
The legacy if= and if!= parameters are available only when ngx_condition_module is not built.
Here is an example:
condition redirect_enabled is_not_empty $http_server_redirect;
when redirect_enabled {
server_redirect newserver.com;
}This example redirects requests to newserver.com if the Server-Redirect header has value and value is not 0.
Syntax: schedule_redirect on | off
Default: schedule_redirect off
Context: server
Redirect the current request to another server from the first request path.
If enabled, when accessing http://a.com/b.com/, the request will be redirected to http://b.com/. If the target server cannot be found, it will be redirected to the default server.
When server_redirect directive exists and meets the redirection conditions, server_redirect will be executed first.
If the request path does not have the first path (such as the home page), no redirection will be made.
After redirection, even $request_uri will be cleared of the first path. You can only find the original request path in the request line variable $request.
Keeps the original value of variable $host before redirection occurs.
Hanada im@hanada.info
This Nginx module is licensed under BSD 2-Clause License.