After trying several technical approaches to either enable SSH traffic or tunnel SSH through HTTP, wstunnel was selected to redirect SSH traffic. While this requires additional installations and configurations on the part of the end user, an SSH tunnel via HTTP over port 80 was achieved.
This model – utilizing a CMS system embedded in a Google Cloud Run instance – is viable for a carefully selected subset of Pantheon’s customers. For example, it’s a good fit for high traffic sites that are mature and stable that want to control costs.