Running a React Dockerfile gives me an error in ubuntu 18 - reactjs

Question

Dockerfile
FROM node:latest AS builder
WORKDIR /app
COPY ./app/
COPY package.json ./
COPY package-lock.json ./
RUN npm install
COPY . ./
RUN npm run build
RUN npm install react-scripts#3.0.1 -g --silent
CMD ["npm", "run", "start"]
docker-compose
webapp:
container_name: webapp
build:
context: ..
dockerfile: app/Dockerfile
ports:
- "3000:3000"
I am trying to build a react project in docker. I can't understand why it can't find index.html? Should it work without nginx?

Answer 1

So it worked
docker-compose
webapp:
container_name: webapp
build:
context: ../zhyvedotnet.auctionthings.webapp
dockerfile: Dockerfile
ports:
- 4200:80
Dockerfile
FROM node:10-alpine as builder
COPY package.json package-lock.json ./
RUN npm install && mkdir /react-ui && mv ./node_modules ./react-ui
WORKDIR /react-ui
COPY . .
RUN npm run build
FROM nginx:alpine
COPY ./nginx/nginx.conf /etc/nginx/nginx.conf
RUN rm -rf /usr/share/nginx/html/*
COPY --from=builder /react-ui/build /usr/share/nginx/html
EXPOSE 3000 80
ENTRYPOINT ["nginx", "-g", "daemon off;"]
nginx.conf
worker_processes 4;
events { worker_connections 1024; }
http {
server {
listen 80;
root /usr/share/nginx/html;
include /etc/nginx/mime.types;
location /appui {
try_files $uri /index.html;
}
}
}