For SLE 12 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/systemsmanagement:chef:master/SLE_12/systemsmanagement:chef:master.repo
zypper refresh
zypper install gecode
For SLE 11 SP3 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/systemsmanagement:chef:master/SLE_11_SP3/systemsmanagement:chef:master.repo
zypper refresh
zypper install gecode
For SLE 11 SP2 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/systemsmanagement:chef:master/SLE_11_SP2/systemsmanagement:chef:master.repo
zypper refresh
zypper install gecode