How to use both ngx.print() and error_page?

[eeeeeunjung]

i am using this configuration:
proxy_intercept_errors on;
error_page 404 /errors/404.html;

but in the location
I configured content_by_lua_file '/nginx_content_phase.luac';
becauser nginx_content_phase.luac contains the ngx.print() directive，error_page doesn't work,

GET /test/123 HTTP/1.1
User-Agent: curl/7.37.0
Host:10.10.15.15:443
Accept: /

HTTP/1.1 404 Not Found
Server product only is not blacklisted
Server: product only
Date: Tue, 11 Jun 2019 01:11:25 GMT
Content-Type: application/octet-stream
Transfer-Encoding: chunked
Connection: keep-alive

it cann't redirect to 404.html,how can i use both ngx.print() and error_page?

[alwaysused]

I think ngx.print() is not relative to the output of server but only does some logging.Using error pages if or not determined by what you do in content_by_lua,such as using coroutines.

[thibaultcha]

If you wish to run Lua code in an error handler location, then don't make error_page point to a static HTML page. Point it to another location block (e.g. error_page ... /my_error_handler) and implement *_by_lua* directives in this new location block, e.g.:

error_page 404 /my_error_handler;

location / {
    proxy_intercept_errors on;
    proxy_pass ...;
}

location = /my_error_handler {
    internal;

    content_by_lua_block {
        ngx.say("my error response")
    }
}

My advice is to use an internal, non-named location block. Named location blocks don't play well with error_page when NGINX didn't parse the URI yet (e.g. when NGINX produces HTTP 414). Unless you define multiple error location blocks for various error scenarios.

Best of luck,