support other upgradeTypes then just websocket

[foosinn]

Description:

Currently this section is automatically added to all dynamic https routes:

[...]
"upgradeConfigs": [
  {
    "upgradeType": "websocket"
  }
]
[...]

I was unable to find a way to modify that. For some tools (in my case https://github.com/juanfont/headscale) it's required to change this value.

It would be awesome to have that configurable. Thanks!

[foosinn]

Found a workaround 🎉

1. Enable EnvoyPatchPolicy: https://gateway.envoyproxy.io/latest/tasks/extensibility/envoy-patch-policy/#enable-envoypatchpolicy

2. Apply the policy to the cluster (replace the Gateway in targetRef and the underscored domain in jsonPath with your values)

---
apiVersion: gateway.envoyproxy.io/v1alpha1
kind: EnvoyPatchPolicy
metadata:
  name: headscale
  namespace: envoy-gateway-system
spec:
  targetRef:
    group: gateway.networking.k8s.io
    kind: Gateway
    name: default
  type: JSONPatch
  jsonPatches:
    - type: "type.googleapis.com/envoy.config.route.v3.RouteConfiguration"
      name: envoy-gateway-system/default/https
      operation:
        op: replace
        jsonPath: "..virtual_hosts[?match(@.name, '.*vpn_example_org')].routes[0].route.upgrade_configs[0]"
        path: upgrade_type
        value: tailscale-control-protocol

[guydc]

Two additional use cases:

• Support an opt-out option for websockets using this mechanism
• Also required by HTTP2 Connect support #3663