Trying to git pull in my web repo directory

I'm using a wordpress with an ispconfig but i have some issue to update my repo by using git pull.

First, I noticed every files permissions by default are : web45 - client0
But when Wordpress generate some files or when I upload files, permissions are : www-data www-data
Is there something wrong here ?

1 - When I try to run "git reset --hard origin/master" have this errors :
fatal: cannot create directory at 'wp-content/cache/supercache/...': Permission denied
This file permission is www-data

2 - I tried to run "sudo -u www-data git pull origin master" but it ask me web45 user password ?

3 - I tried to run "chown -R web45:client0 /home/www/clients/client0/web45/web" but can't cause of www-data permissions files.

Can I force apache to use web45 user for every files except www-data ? Or this behavior normal ?
Or did i try to do something wrong ? What should I so to use git properly ?

(My website conf is : MOD-PHP // Suexec neable => I dont know if its important but give you also this information)

Need your help... Thanks very much !

 

Ok I think I solved my issue.

First : I set my website to PHP FAST-CGI in website setting of ISPCONFIG. Now every file are created by the correct user.
Second : I logged in with root in ssh and run : chown -R web45:client0 /home/www/clients/client0/web45/web
Third : run "git pull" with my normal ssh user

it works !
can you tell me if i'm doing the correct way.

Thanks