rubykubernetessinatrarack

Sinatra On Kubernetes - Moved app to subdirectory, app assets fail to render in production (404) but work locally

My code: https://github.com/nullset2/smbdxfortunes

Hi. My setup is as follows:

  1. Sinatra app
  2. Ruby 2.7
  3. Kubernetes 1.17
  4. Traefik Ingress as "Reverse proxy"

I originally had this application working fine on the root of my server: nullset2.zapto.org (which resolves through DDNS to the IP of my router), and now I wish to move this application so it's served from nullset2.zapto.org/smbdxfortunes.

My sinatra app uses the convention that assets and static files should live in a ./public subdirectory, from where it reads a small landing page and listens to requests for another route, does a small query and returns an erb file.

I have configured the Ingress so it resolves to the correct applications depending on the route and rewritten the application code so it listens on the /smbdxfortunes route. For some reason the application will work perfectly locally, and render a page from public/index.html with all assets --however when I containerize it and deploy it on my kubernetes cluster, the app will work but all static files referenced in public/index.html will return HTTP 400. The website itself will be rendered, but with all broken images and no styles.

Things I've tried to no avail:

  1. Setting set :base_path, '/smbdxfortunes' in my fortune.rb sinatra module.
  2. Setting set :static, true in my fortune.rb.
  3. Modifying the actual paths that the assets are read from in my index.html to account for the subdirectory (e.g. img/vine.png becomes /smbdxfortunes/img/vine.png)
  4. Setting config.ru like this and changing the CMD statement in my dockerfile to use rackup:
require './fortune'
use Rack::Static, :urls => ['/css', '/js', '/img', '/wav'], :root => 'public'
run Sinatra::Application

Any help is appreciated.

Solution

  • Not an answer per-se, but a workaround: I managed to work around this problem by pointing both my / and /smbdxfortunes routes on my ingress to the same service, so all requests for static assets go to the sinatra public subdirectory, and requests to the root otherwise return a 404.

    ---
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: nullset2-ingress
  annotations:
    kubernetes.io/ingress.class: traefik
    cert-manager.io/cluster-issuer: letsencrypt-prod
    traefik.ingress.kubernetes.io/router.middlewares: default-redirect-https@kubernetescrd
    traefik.frontend.rule.type: PathPrefix
spec:
  rules:
  - http:
      paths:
      - path: /
        backend:
          serviceName: smbdxfortunes
          servicePort: 80
      - path: /smbdxfortunes
        backend:
          serviceName: smbdxfortunes
          servicePort: 80
      - path: /pixy
        backend:
          serviceName: pixy
          servicePort: 80
  tls:
    - secretName: nullset2-tls
      hosts:
        - ${DOMAIN}