As other have suggested, Nebula (https://github.com/slackhq/nebula https://github.com/slackhq/nebula) is pretty elegant. It has groups-based access built in whi

As other have suggested, Nebula (https://github.com/slackhq/nebula https://github.com/slackhq/nebula) is pretty elegant. It has groups-based access built in which is extremely convenient. You can bolt-on SSO fairly easily - just create a certificate signing service. I created https://github.com/unreality/nebula-mesh-admin https://github.com/unreality/nebula-mesh-admin in a weekend, so its fairly easy to add a SSO flow in.