Create function that accepts function

I have a function that runs some fairly generic code that does a lot of work connection to a database and setting up different configuration variables. Lets not get into the ethics of this, please bare with me. I have within a couple of if statements of this top-level function code that I run that is actually different from function to function.

This is how it looks now.

function get_users(){
   // config
   // set application keys
   // connect to database
   // retrieve user data
   // authentication to foreign api
   if(something){
     // some more red-tape
     if(something){
       //more more
       if(something){
         /* finally the good stuff */
 
         // the code here varies from function to function
         // eg. get users
         // probably will run: inner_get_users();
 
       }
     }
   }
 }
 
 function get_data(){
   // config
   // set application keys
   // connect to database
   // retrieve user data
   // authentication to foreign api
   if(something){
     // some more red-tape
     if(something){
       //more more
       if(something){
         /* finally the good stuff */
 
         // the code here varies from function to function
         // eg. get data
         // probably will run: inner_get_data();
 
       }
     }
   }
 }
 

How I want it to work:

function instance($inner){
   // config
   // set application keys
   // connect to database
   // retrieve user data
   // authentication to foreign api
   if(something){
     // some more red-tape
     if(something){
       //more more
       if(something){
         /* finally the good stuff */
 
         Call inner
 
       }
     }
   }
 }
 
 function get_data(){
 
 
   instance(function(
     // get the data
   ));
 
 }
 

or maybe

function get_users(){
 
   $var = function(
     // get the users
   );
 
   instance($var);
 
 }
 

I'm looking for better, dryer, and more maintainable code.

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