rsync will just use whatever user it is being run as, which for SitePush means the user your web server runs under for any given site. If your dev site and live site are running under different users then this is always going to be a bit tricky.
If you can, set things up so that live and dev sites run under the same user. Alternatively if that’s not possible, you could set it so both users are members of the same group, and make sure that all files on both sites are group writeable.
Whether or not any of this is possible really depends on your server setup. If you are on a shared server managed by a hosting company it’s possible they won’t let you do any of that.
Two other things to consider if you are on shared hosting:-
- make the dev site a subdomain install of the live site. Sometimes subdomains have the same user/permissions as the main site.
- have both dev and live sites on the same vhost as described in SitePush docs – there are some disadvantages to that setup, but at least file permissions won’t be an issue.
Do let me know how you get on.