For openSUSE Leap 42.3 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/isv:ownCloud:devel:obs-2.9/openSUSE_Leap_42.3/isv:ownCloud:devel:obs-2.9.repo
zypper refresh
zypper install dpkg
For openSUSE Leap 42.2 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/isv:ownCloud:devel:obs-2.9/openSUSE_Leap_42.2/isv:ownCloud:devel:obs-2.9.repo
zypper refresh
zypper install dpkg
For openSUSE Leap 42.1 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/isv:ownCloud:devel:obs-2.9/openSUSE_Leap_42.1/isv:ownCloud:devel:obs-2.9.repo
zypper refresh
zypper install dpkg