nginx:读取NJS子请求的响应头

Question

我正在尝试使用nginx的njs模块和子请求将两个请求链接在一起。我可以看到在响应头中返回了special_value，但是我不知道如何使用proxy_set_header来读取值。以下代码将导致X-Special-Value中的值为空值

nginx.conf：

location ~* /step_one {
  js_content njs_func;
}

location ~* /step_two {
  proxy_pass       http://some_other/api;
  proxy_set_header X-Special-Value      $http_special_val;
}

http.js

function njs_func(r) {
    r.headersOut['special_val'] = '42';
    r.subrequest('/step_two')
     .then(reply => r.return(reply.status, reply.responseBody));
}

Answer 1

你可以这样做：

nginx.conf

set $specialValue "";

location ~* /step_one {
  js_content njs_func;
}

location ~* /step_two {
  proxy_pass       http://some_other/api;
  proxy_set_header X-Special-Value      $specialValue;
}

https.js

function njs_func(r) {
    r.variables.specialValue = '42';
    r.subrequest('/step_two')
     .then(reply => r.return(reply.status, reply.responseBody));
}