package update dependency cycles in puppet-tripleo

[James Slagle]

The way that packages.pp from puppet-tripleo is expressing dependency chains for the yum upgrade is not working.

What if your Puppet manifests/modules have something like:
  Service['my-service'] -> Package['my-package']

By this code, we're exposed to dependency cycles and we don't want that.
See this test with TripleO:
  Exec[package-upgrade] => Service[openvswitch] => Class[Vswitch::Ovs] => Class[Neutron::Agents::Ml2::Ovs] => Package[neutron-ovs-agent] => Exec[package-upgrade]

The problem here is that puppet-neutron says: "OVS service needs to run before installing+configuring Neutron OVS agent [1]. In short, we have:
  Service['ovs'] -> Package['neutron-ovs-agent']
because of the require "vswitch::ovs" in puppet-neutron.

We have two options I think:

    patch puppet-neutron to improve orchestration and be more cool with the requirements. There is a risk we have this situation in other modules!
    change this chain (L66) to make it more flexible with less risk of cycle dependency issue.

I'm about to provide a patch in master for solution #2, and I'll WIP it. Feel free to look.

[1] https://github.com/openstack/puppet-neutron/blob/master/manifests/agents/ml2/ovs.pp#L151

[James Slagle (james-slagle)]

proposed fix in puppet-tripleo: https://review.openstack.org/#/c/268388

[Doug Hellmann (doug-hellmann)]

This issue was fixed in the openstack/puppet-tripleo 0.4.0 release.

[Brad P. Crochet (brad-9)]

Reopening. Upon enabling puppet runs during minor update, a new dependency cycle was found.

Error: Failed to apply catalog: Found 1 dependency cycle:
(Exec[/usr/bin/systemctl daemon-reload] => Service[iptables] => Class[Firewall::Linux::Redhat] => Stage[setup] => Stage[main] => Class[Tripleo::Packages] => Exec[package-upgrade] => Service[iptables])

[Emilien Macchi (emilienm)]

Trying to fix it here: https://review.openstack.org/386637

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/puppet-tripleo 0.4.0 release.