For future travellers, on the off chance like us you're trying to deploy juju 2.8 + openstack from charmstore to reproduce upgrades.
To work around this issue, first deploy a juju 2.8.13 controller using the 2.8.13 client. But then switch back to 2.9/stable (2.9.43) before deploying the model/bundle - then it will deploy fine to the 2.8 controller without the "bad metadata: resource missing filename" error for policyd-override on the various charms (cinder/glance/etc). That part seems fixed on the client side and 2.9.43 client works fine against a 2.8.13 controller.
"juju deploy glance" also works fine, it only fails when using a bundle/bundle including overlays. Manually doing 'juju deploy' steps is another possible workaround.
For future travellers, on the off chance like us you're trying to deploy juju 2.8 + openstack from charmstore to reproduce upgrades.
To work around this issue, first deploy a juju 2.8.13 controller using the 2.8.13 client. But then switch back to 2.9/stable (2.9.43) before deploying the model/bundle - then it will deploy fine to the 2.8 controller without the "bad metadata: resource missing filename" error for policyd-override on the various charms (cinder/ glance/ etc). That part seems fixed on the client side and 2.9.43 client works fine against a 2.8.13 controller.
"juju deploy glance" also works fine, it only fails when using a bundle/bundle including overlays. Manually doing 'juju deploy' steps is another possible workaround.