Making an RPM which sets POSIX files capabilities

Question

How does one make an RPM which sets the POSIX capabilities of a file? If I try doing rpmbuild as a non-root user then I get an error when my makefile's install hooks try to run setcap, but if I don't run setcap how will rpmbuild copy the capabilities? There doesn't seem to be any way to set the capability from within the RPM spec file.

Judithjuditha

Answer 1

There is a spec file macro for setting capabilities, %caps; for some reason this seems to be mainly documented in the release notes and changelogs, so it took a while for me to find it.

It's used like this in the spec file:

%caps(cap_net_admin=pe) %{_sbindir}/foobar

To get make install to use setcap only when invoked by root, you can do something like this:

@if test `id -u` -eq 0; then \
    setcap cap_net_admin=pe $(DEST_SBINDIR)/foobar ; \
fi

Judithjuditha

I wasn't able to get the %caps directive to work. Was getting syntax error near unexpected token `cap_net_raw+ep'. Found another solution using %post as described in this issue: github.com/schweikert/fping/issues/24#issue-5647305 – Pep

Hopefully undocumented for not too much longer. – Takeo