create a tunnel with port-forward, add route to virtual interface, like tun0, forward traffic though tunnel to remote traffic manager.
base on connect mode, inject a container to controller, use iptables to block all inbound traffic and forward to local though tunnel.
┌──────────┐ ┌─────────┌──────────┐ ┌──────────┐
│ ServiceA ├───►│ sidecar │ ServiceB │ ┌─►│ ServiceC │
└──────────┘ └────┌────┘──────────┘ │ └──────────┘
│ │
│ │ cloud
─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ┘─ ─ ─ ─ ─ ─ ─ ─ ─┘ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─
│ │ local
┌───┘──────┐ │
│ ServiceB'├──────────┘
└──────────┘
base on reverse mode, using envoy as proxy, if headers have special key-value pair, it will route to local machine, if not, use origin service.
┌──────────┐ ┌─────────┌────────────┐ ┌──────────┐
│ ServiceA ├───►│ sidecar ├─► ServiceB │─►┌─►│ ServiceC │
└──────────┘ └────┌────┘────────────┘ │ └──────────┘
│ │ cloud
─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─┘─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ┘ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─
│ │ local
header: foo=bar │
┌───┘──────┐ │
│ ServiceB'├─────────────┘
└──────────┘