Is it safe to add repositories?

Question

ubuntu

Interested in whether it is safe to add third-party repositories to a development/production server running ubuntu server?
For example, I found a repository with PHP7, is everything ok there? Is there a way to install this?

Answer 1

Depends on the repository =)
In general, in the general case - no, if only verified and publicly recognized (as, for example, debian backports used to be).
Dotdeb also seems to be publicly recognized, and outright viruses are unlikely to get there, but they don’t always try to collect packages there, they collect them "as best they can".

Answer 2

Sources are open - check
You can build yourself a package from the git

Answer 3

any repository you add at your own peril and risk
, there is no way to check it, except to compile the package yourself