I am trying to adopt a git branching strategy in our office, but it requires that all merges are made without using fast forward. Since we all use different tools to work with git, I would like to know if it's possible to configure Gitolite to prohibit pushes with fast forward merges? Is it even possible to detect that kind of merge?
git config merge.ff false
See https://git-scm.com/docs/git-config#git-config-mergeff
No, it's not possible to detect because it's not a merge at all.