# Path prefixes

> What pathPrefix and rewritePath do, and which to choose behind an Ingress, a Gateway or your own proxy.

Behind an Ingress or a Gateway, several apps often share one address, each under its own path. `pathPrefix` puts hello-kubernetes under a path such as `/app/hello`. `rewritePath` says which side removes that path: the proxy, or nobody.

## What each setting does

`rewritePath: false` (recommended)

1. Browser: asks for `/app/hello/`
2. Ingress or Gateway: passes on `/app/hello/`
3. App: serves at `/app/hello/`, and links its assets as `/app/hello/css/main.css`

`rewritePath: true`

1. Browser: asks for `/app/hello/`
2. Ingress or Gateway: strips the prefix, and passes on `/`
3. App: serves at `/`, and links its assets as `/app/hello/css/main.css`

In both cases, the page links its stylesheet and images under the prefix, so the browser asks the proxy for them by the full path.

| `rewritePath` | The proxy | Works with |
| - | - | - |
| `false` (recommended) | passes the path on unchanged | every Ingress controller and Gateway, with no annotations |
| `true` (the 1.x default) | strips the prefix | an HTTPRoute, which uses the standard `URLRewrite` filter. An Ingress needs your controller’s rewrite annotation. |

Choose `rewritePath=false` unless you have a reason not to. The default changes to `false` in 2.0, so set it now and nothing changes for you then.

## Set them

```bash
helm install hello oci://ghcr.io/paulbouwer/charts/hello-kubernetes \
  --set pathPrefix=/app/hello --set rewritePath=false \
  --set ingress.enabled=true --set ingress.className=traefik \
  --set service.type=ClusterIP
```

Leading and trailing slashes are optional: `app/hello`, `/app/hello` and `/app/hello/` are the same prefix. The chart sets the Ingress or HTTPRoute path, the app’s own path and the probes’ path together.

For the full steps, see [Behind an Ingress](https://paulbouwer.github.io/hello-kubernetes/docs/deploy/ingress.md) or [Behind a Gateway](https://paulbouwer.github.io/hello-kubernetes/docs/deploy/gateway.md). Without the chart, the app reads two [settings](https://paulbouwer.github.io/hello-kubernetes/docs/reference/app-settings.md): `HANDLER_PATH_PREFIX`, the path it serves under, and `RENDER_PATH_PREFIX`, the path its links use.

## Your own proxy

With your own proxy or Ingress, set `pathPrefix` and `rewritePath`, but leave `ingress.enabled` and `httpRoute.enabled` off. Point your proxy at the Service `hello-kubernetes-<release name>`, port `80`.