Question

We are planning on having a policy to prevent commits to trunk. All commits must happen against branches.

What should be my approach to get this done?

Answer 1

See the svn documentation. IT says both apache and svnserve support path-based authorization. Also, from the documentation:

Do you really need path-based access
control?

A lot of administrators setting up
Subversion for the first time tend to
jump into path-based access control
without giving it a lot of thought.
The administrator usually knows which
teams of people are working on which
projects, so it’s easy to jump in and
grant certain teams access to certain
directories and not others. It seems
like a natural thing, and it appeases
the administrator’s desire to maintain
tight control of the repository.

Note, though, that there are often
invisible (and visible!) costs
associated with this feature. In the
visible category, the server needs to
do a lot more work to ensure that the
user has the right to read or write
each specific path; in certain
situations, there’s very noticeable
performance loss. In the invisible
category, consider the culture you’re
creating. Most of the time, while
certain users shouldn’t be committing
changes to certain parts of the
repository, that social contract
doesn’t need to be technologically
enforced. Teams can sometimes
spontaneously collaborate with each
other; someone may want to help
someone else out by committing to an
area she doesn’t normally work on. By
preventing this sort of thing at the
server level, you’re setting up
barriers to unexpected collaboration.
You’re also creating a bunch of rules
that need to be maintained as projects
develop, new users are added, and so
on. It’s a bunch of extra work to
maintain.

Remember that this is a version
control system! Even if somebody
accidentally commits a change to
something they shouldn’t, it’s easy to
undo the change. And if a user commits
to the wrong place with deliberate
malice, then it’s a social problem
anyway, and that the problem needs to
be dealt with outside of Subversion.