Comment 0 for bug 1693192

Patch [1] enabled etcd3 by default in devstack. Patch [2] adds the ability to disable etcd3 - this gets s390x devstack working again when the following line is in local.conf

  disable_service etcd3

But this is just a circumvention. The root cause is NOT that etcd3 is not working on s390x (it is working!! [5]), but that devstack downloads the (architecture dependent) binaries directly from github.com, e.g. [3]. But etcd does not provide binaries for s390x on github.
Devstack does so, as most distros do not yet have the etcd3.x version available (e.g. with ubutnu 16 it's 2.x).

I opened an issue against etcd to figure out what would need to be done to get that going [4].

Alternatively the following approaches are thinkable:

- Enhance devstack to download the binary and compile it
- Enhance devstack to check whether etcd3 is already installed and use it - otherwise fail for s390x

[1] https://github.com/openstack-dev/devstack/commit/546656fc0543ec2bc5b422fd9eee17f1b8122758
[2] https://review.openstack.org/467597
[3] https://github.com/coreos/etcd/releases/tag/v3.2.0-rc.1
[4] https://github.com/coreos/etcd/issues/7978
[5] https://github.com/linux-on-ibm-z/docs/wiki/Building-etcd?cm_mc_uid=&cm_mc_sid_50200000=1490870911