Hi Stuart,

thanks for the reply - I got a similar tip on the keycloak-user list however if I configure the default-response-code=503
on the (single) host element of the undertow subsystem in Wildfly (10.1.0) and restart the server then I get a 
404 but never a 503 when I access paths of an web app (keycloak) that is not fully initialized yet.

Seems that I'm seeing the same behaviour as those folks:
https://developer.jboss.org/thread/257526

Is there anything else that one needs to configure to make this work?

In the meantime I played a bit with alternative approaches e.g.: https://github.com/thomasdarimont/undertow-extensions

Cheers,
Thomas

2017-01-30 22:09 GMT+01:00 Stuart Douglas <sdouglas@redhat.com>:
You can add the default-response-code attribute in the host element of
the undertow subsystem to make it return 503 by default.

Stuart

On Mon, Jan 30, 2017 at 9:34 PM, Thomas Darimont
<thomas.darimont@googlemail.com> wrote:
> Hello group,
>
> (coss-post from keycloak-user Mailing List)
>
> the undertow servlet-container is started pretty early during the startup of
> the
> wildfly application server. However the initialization of the keycloak
> server
> application might take a while to complete. Within this period requests that
> are
> sent to the keycloak endpoints result in responses with HTTP Status Code
> 404.
>
> Is it possible to configure undertow to return a HTTP Status Code 503
> (Service Unvailable)
> until the keycloak application startup has completed?
>
> This would ease configuring load-balancers and to avoid showing a file not
> found
> to users during server restarts.
>
> Cheers,
> Thomas
>
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