replacing the haproxy error page in openshift origin

first, create a configmap secret which will contain the 503 page

apiVersion: v1
  error-page-503.http: |-
    HTTP/1.0 503 Service Unavailable
    Pragma: no-cache
    Cache-Control: private, max-age=0, no-cache, no-store
    Connection: close
    Content-Type: text/html

    <html><head><body>We'll be back!</body></head></html>
kind: ConfigMap
  name: haproxy-error-page
  namespace: default

then create it

oc -n default create -f haproxy-error-page.yml

now you need to add it as a volume

oc -n default set volume --add --configmap-name=haproxy-error-page dc/router -m /var/lib/haproxy/conf/error-page-503.http --name=haproxy-config-volume

and patch the router config (see for why this is necessary)

oc -n default patch dc router -p '{"spec":{"template":{"spec":{"containers":[{"volumeMounts":[{"mountPath":"/var/lib/haproxy/conf/error-page-503.http","subPath":"error-page-503.http","name":"haproxy-config-volume"}],"name":"router"}]}}}}

selinux also has to be disabled on the router box (for now)