Accessing xpra html5 client behind a ingress controller - reverse-proxy

Question

I am trying to host and remotely access kicad(pcb software) on a kubernetes cluster using html5 client .
dockerfile:
FROM python:3.9.0-slim-buster
RUN apt-get update && apt install -y \
software-properties-common \
wget \
gnupg2
#install xpra
RUN wget -q https://xpra.org/gpg.asc -O- | apt-key add - && \
add-apt-repository "deb https://xpra.org/ buster main" && \
apt-get update && apt-get install -y --no-install-recommends xpra xvfb xterm
##install dependencies
RUN apt-get update && apt install -y \
libx11-dev libxcomposite-dev libxdamage-dev \
libxkbfile-dev \
openssh-client \
sshpass \
python3-paramiko \
dbus-x11 \
python3-requests \
xpra-html5
#install kicad
RUN apt-get update && add-apt-repository -y ppa:kicad/kicad-5.1-releases && \
apt-get install -y --no-install-recommends kicad \
&& rm -rf /var/lib/apt/lists/*
ENV DISPLAY=:0
EXPOSE 8051
CMD xpra start --start=kicad --no-pulseaudio --bind-tcp=0.0.0.0:8051 --html=on && tail -f /dev/null
deployment file:
apiVersion: apps/v1
kind: Deployment
metadata:
name: kicad-deployment
labels:
app: kicad
spec:
replicas: 2
selector:
matchLabels:
app: kicad
template:
metadata:
labels:
app: kicad
spec:
containers:
- name: kicad
image: syashfr/kicad:1.0.0
ports:
- containerPort: 8051
service file:
apiVersion: v1
kind: Service
metadata:
name: kicad-service
spec:
type: LoadBalancer
selector:
app: kicad
ports:
- port: 80
targetPort: 8051
ingress file:
kind: Ingress
metadata:
name: kicad-ingress
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /
spec:
rules:
- http:
paths:
- path: /kicad
backend:
serviceName: kicad-service
servicePort: 80
I assume proxy_pass should be automatically on applying ingress.yaml, therefore I have not made changes to nginx.conf (ingress controller) as stated in https://xpra.org/trac/wiki/Nginx
However when I try to access the application: http://ingress_address/kicad, I get the following page instead of the application UI:
It does seem that I am routed to my service, but not to the expected UI. I can however, access the kicad UI through external IP of the service. What am I missing with ingress ?

Answer 1

I've reproduced your issue and solved it by slightly modifying the ingress resource. My ingress object manifest:
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
name: kicad-ingress
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /$1
kubernetes.io/ingress.class: nginx
spec:
rules:
- http:
paths:
- path: /kicad/?(.*)
backend:
serviceName: kicad-service
servicePort: 80
Deployment and service yamls remained untouched. When you try to access <ingress-IP>/kicad/ you will see expected UI.