Spring boot admin Kubernetes Ingress

Question

I'm trying to add an spring boot admin interface to some microservice that are deployed in kubernetes cluster. the spring boot admin app has the following configuration:

spring:
        application:
          name: administrator-interface
        boot:
          admin:
            context-path: "/ui"
      server:
        use-forward-headers: true

The kubernetes cluster has an ingress that works as an api gateway:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: {{ template "fullname" . }}
  labels:
    app: {{ template "name" . }}
    chart: {{ .Chart.Name }}-{{ .Chart.Version | replace "+" "_" }}
    release: {{ .Release.Name }}
    heritage: {{ .Release.Service }}
  annotations:
    {{- range $key, $value := .Values.ingress.annotations }}
    {{ $key }}: {{ $value | quote }}
    {{- end }}
    nginx.ingress.kubernetes.io/rewrite-target: /$1
spec:
  rules:
    {{- range $host := .Values.ingress.hosts }}
    - host: {{ $host }}
      http:
        paths:
          - path: /admin/(.+)
            backend:
              serviceName: administrator-interface-back
              servicePort: 8080
    {{- end -}}
  {{- if .Values.ingress.tls }}
  tls:
{{ toYaml .Values.ingress.tls | indent 4 }}
  {{- end -}}
{{- end -}}

when I try to see the spring boot admin ui I had the following error:

URL in explorer: https://XXXXXX(thisisgivenBYDNS)/admin/ui

GET https://XXXXXX/ui/assets/css/chunk-common.6aba055e.css net::ERR_ABORTED 404

The URL is wrong because it should be https://XXXXXX/admin/ui/assets/css/chunk-common.6aba055e.css

It is not adding the /admin path that is given by the ingess

How can i solve this and configure an aditional path to serve the static content in the request from the right URL?

Thanks in advance

Answer 1

The problem is that your spring boot admin interface has no way to know that you're using "/admin" suburl.

nginx.ingress.kubernetes.io/rewrite-target: /$1 ask nginx to rewrite your url matching the second group. So when you're hitting: https://XXXXX/admin/ui nginx rewrite your url to https://XXXXXX/ui and then send it to spring boot.

I don't know well spring boot but you should have a way to provide him a suburl so instead of serving to /ui it server to /$BASE_URL/ui.

Then weather how it works you might need to change how nginx rewrite the url by something like:

• path: ^(/admin/)(.+)\
• nginx.ingress.kubernetes.io/rewrite-target: $1/$2

Answer 2

Finally I found the solution.

Spring boot admin has a tool for that called "public URL"

      spring:
        application:
          name: administrator-interface
        boot:
          admin:
            context-path: "/ui"
            ui:
              public-url: "https://XXX/admin/ui"
      server:
        use-forward-headers: true

whith such configuration I am telling spring boot admin that i want to connect with a context /ui but when trying to load resources it should make the request to /admin/ui.

Now i can connect with the interface trought https:/XXX/ui and is sending request to load resources from https://XXX/admin/ui adding the prefix set by ingress

Thank you @Noé