Add ingress-nginx migration docs

[tr0njavolta]

Description

Updates docs for ingress-nginx to Envoy for Spaces. https://docs.google.com/document/d/1ZfE7kZTAmKKjHkt6dFNRzki9S6wRnpHbzXa86LVcDw0/edit?tab=t.0#heading=h.valiw6ek06tp

Type of change

• Bug fix (typo, broken link, incorrect info)
• Content update (new info, clarification, reorganization)
• New content (new page, section, or guide)

Checklist

• I ran make lint locally (or will fix Vale suggestions in review)
• Links work and point to the right places
• If this adds new content, I tested the examples/instructions

Additional notes

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Project	Deployment	Actions	Updated (UTC)
docs	Ready	Preview, Comment	Jan 29, 2026 8:21pm

[cbuto]

FYI we wrote up a project around how to handle this in Spaces - https://linear.app/upbound/project/migrate-away-from-ingress-nginx-in-spaces-4f46a7c99c3f/overview

I'd like us to understand our options a bit more, specifically around what we are suggesting for the Gateway API implementation i.e. envoy gateway.

[cbuto]

thanks @tr0njavolta, left some comments 👍

[cbuto]

the GatewayClass would remain consistent between cloud providers, but the underlying EnvoyProxy config resource would change accordingly

[cbuto]

might be worth not defining an explicit version here, so we don't have to update it later on?

[cbuto]

Similar to an above comment, the GatewayClass would remain consistent between clouds but the underlying EnvoyProxy config would differ.

we could show different configs per cloud, then just always have the same GatewayClass applied

[cbuto]

I think we should point users towards using the helm values first, so they aren't manually creating these resources and later find these are included in the helm chart.

After creating the GatewayClass and EnvoyProxy config, they can do a helm upgrade with the values referenced in the section below

ingress:
  provision: false

gatewayAPI:
  host: proxy.example.com  # Must match your current ingress.host
  gateway:
    provision: true
    name: spaces
    className: spaces  # Must match your GatewayClass name
  spacesRouterRoute:
    provision: true
  # Labels for NetworkPolicy - must match your gateway controller's pods
  podLabels:
    app.kubernetes.io/name: envoy
    app.kubernetes.io/component: proxy
    app.kubernetes.io/managed-by: envoy-gateway
  namespaceLabels:
    kubernetes.io/metadata.name: envoy-gateway-system

[cbuto]

starting in Spaces 1.16, we'll want to update this to default to load balancer service.

then we could optionally point users to docs/manuals/spaces/howtos/self-hosted/ingress.md if they need Gateway or Ingress.

[cbuto]

should we have details around how to use Gateway API here?

similar to what we have in the installation docs 🤔