Cp-docker-images: Make URL's in Confluent Control-Center front-end UI relative iso absolute

Created on 13 Jan 2018 · 8Comments · Source: confluentinc/cp-docker-images

Hi all,

I am using the docker images of confluent to deploy the confluent stack (kafka, zookeeper, schema-registry, rest-proxy and control-center) on Kubernetes. I am using an nginx ingress controller to expose the control center's dashboard (using path routing):

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: ingress-control-center
  annotations:
    ingress.kubernetes.io/rewrite-target: /
    ingress.kubernetes.io/add-base-url: "true"
spec:
  rules:
  - http:
      paths:
      - path: /control-center
        backend:
          serviceName: control-center-svc
          servicePort: 9021

The ingress.kubernetes.io/add-base-url ensures that in the HTML returned, a base-url header is injected in order for later scripts/urls to be correctly resolvable over the path based ingress controller. The result looks like this:

<!DOCTYPE html>
<html>
  <head><base href="https://kubernetes-ingress.mydomain.com/control-center/">
    <meta http-equiv="Content-type" content="text/html; charset=utf-8">
    <title>Control Center</title>
  <link rel="shortcut icon" href="/dist/favicon.ico"><link href="/dist/main-14ed7341cd326a596d21.css" rel="stylesheet"></head>
  <body>
    <div id="controlcenter" style="height: 100%"></div>
  <script type="text/javascript" src="/dist/manifest.js"></script><script type="text/javascript" src="/dist/vendor.js"></script><script type="text/javascript" src="/dist/main.js"></script></body>
</html>

As one can see, the links however all are using absolute URL's, which is why the page is not properly loading behind this nginx reverse proxy.

I was wondering if you would be willing to switch the URL's to be relative (I would try to change this myself using some linux _sed_ magic, but it seems that the code is embedded in a jar).

REF: https://github.com/kubernetes/ingress-nginx/blob/master/docs/annotations.md

PS: not sure this is the right repo, but I could not find a control-center specific one.
PPS: the result of the port-confluent-to-kubernetes exercise (I had to extend the docker images of Kafka and Zookeeper to make it work FYI):

# kubectl version
Client Version: version.Info{Major:"1", Minor:"9", GitVersion:"v1.9.1", GitCommit:"3a1c9449a956b6026f075fa3134ff92f7d55f812", GitTreeState:"clean", BuildDate:"2018-01-04T19:58:48Z", GoVersion:"go1.9.2", Compiler:"gc", Platform:"darwin/amd64"}
Server Version: version.Info{Major:"1", Minor:"8", GitVersion:"v1.8.6", GitCommit:"6260bb08c46c31eea6cb538b34a9ceb3e406689c", GitTreeState:"clean", BuildDate:"2017-12-21T06:23:29Z", GoVersion:"go1.8.3", Compiler:"gc", Platform:"linux/amd64"}

# kubectl get pods -o wide
NAME                              READY     STATUS              RESTARTS   AGE       IP              NODE
control-center-ff6995d6-l2pbd     1/1       Running             0          1h        172.24.38.205   node-172-16-24-36
kafka-0                           1/1       Running             0          1h        172.24.27.107   node-172-16-24-24
kafka-1                           1/1       Running             0          1h        172.24.28.23    node-172-16-24-28
kafka-2                           1/1       Running             0          1h        172.24.38.192   node-172-16-24-36
kafka-connect-6c7f78cf4f-lwjn5    1/1       Running             0          16m       172.24.39.107   node-172-16-24-36
rest-proxy-578494fd86-b4cmg       1/1       Running             0          11m       172.24.39.117   node-172-16-24-36
schema-registry-b8996c9b5-xj4qj   1/1       Running             0          1h        172.24.27.114   node-172-16-24-24
zookeeper-0                       1/1       Running             0          1h        172.24.38.180   node-172-16-24-36
zookeeper-1                       1/1       Running             0          1h        172.24.27.100   node-172-16-24-24
zookeeper-2                       1/1       Running             0          1h        172.24.21.14    node-172-16-24-20

Source

boeboe

👍12

Most helpful comment

Can we get this fixed quickly? Not good for an enterprise tool!!

Durairaj on 28 Feb 2020

👍3

All 8 comments

Do you mind share you're experience with kubernetes ? Stability etc...

Patafix on 19 Mar 2018

We didn't see stability issues so far. Partitioning/replication in combo with a flexible scalable kubernetes platform is an ideal combo.

boeboe on 19 Mar 2018

We are running into the same issue; actually we run 2 CP releases on one k8s cluster and like to route both control-center UI's over one ingress-controller. We use the sub_filter to rewrite paths in the response but it doesn't work for .js packages being send back that initialize the frontend.

What is needed is support for proxy on a path by the app itself.

annotations:
  kubernetes.io/ingress.class: "nginx"
  nginx.ingress.kubernetes.io/force-ssl-redirect: "true"
  nginx.ingress.kubernetes.io/rewrite-target: /$2
  nginx.ingress.kubernetes.io/use-regex: "true"
  nginx.ingress.kubernetes.io/auth-type: basic
  nginx.ingress.kubernetes.io/auth-secret: basic-auth-admin
  nginx.ingress.kubernetes.io/auth-realm: "Authentication Required"
  nginx.ingress.kubernetes.io/configuration-snippet: |
    proxy_set_header Accept-Encoding "";
    sub_filter_once off;
    sub_filter 'href="/dist/' 'href="/control-center/dist/';
    sub_filter 'src="/dist/' 'src="/control-center/dist/';

Alternatives would be to distinguish on host or port on the ingress and leave the control-center in the root (but both are not an option for us).

Paul424 on 18 Dec 2019

It should be a simple change in the jar file, but that's up to Confluent team to take this issue serious.

boeboe on 18 Dec 2019

👍3

Can we get this fixed quickly? Not good for an enterprise tool!!

Durairaj on 28 Feb 2020

👍3

Was looking for the setting to do this and found it doesn't yet exist! This feature is a must have for our deployment.

thejml on 2 Sep 2020

Because of security it should be possible to access the control center through kubectl proxy instead of an ingress but this isn't possible because of the absolute urls.