Docker multiple ports (frontend&backend) not working

Question

I'm very new to Docker and CI's so please be don't grill me:)

I'm on Linode and I would like to to run the frontend(react) and backend(python) on the same server. Both will be on separate ports, unless you tell me that this is a wrong approach.

Now, I'm running Jenkins on port 8081 and have two individual jobs:

Backend Jenkins:

IMAGE = "my_docker_flask:latest"
image = docker.build("${IMAGE}");
def container = image.run('-p 5000:5000')
def contport = container.port(5000)

Backend Dockerfile (flask):

FROM python:2.7
WORKDIR app
COPY . .
RUN pip install -r requirements.txt
ENTRYPOINT ["python"]
CMD ["app.py"]

Frontend Jenkins:

IMAGE = "reactapp"
image = docker.build("${IMAGE}")
def container = image.run('-p 6000:6000')
def contport = container.port(6000)

Frontend Dockerfile:

FROM nginx
COPY build /var/www

The backend works fine when I open my Linode's IP with port 5000 but the 6000 does not work. I even tried with 3333 but that does not work either and.

Here's my docker ps -a :

reactapp  "nginx -g 'daemon of…"   41 seconds ago      Up 40 seconds       80/tcp, 0.0.0.0:6000->6000/tcp
reactapp  "nginx -g 'daemon of…"   2 days ago          Up 2 days           80/tcp, 0.0.0.0:3333->3333/tcp
my_docker_flask:latest   "python app.py"   2 days ago          Up 2 days           0.0.0.0:5000->5000/tcp

Can please someone help me?

How can I run multiple apps on different ports using the same IP?

EDIT

I have fixed it but changing to the below:

COPY build /usr/share/nginx/html

and

def container = image.run('-p 5000:80')

Answer 1

80/tcp, 0.0.0.0:6000->6000/tcp

Looking at this carefully, we can know that your reactapp service is being served at port 80 within the container. But you are trying to map the port 6000 in the container to port 6000 outside. Certainly, you will not be able to access a service where it is not being served at all.

Also, the reason behind This site can't be reached - ERR_UNSAFE_PORT is because you are using the port 6000 which is restricted by the Chrome browser.

Solution:

• map the port 80 only and not any other port as it is being served at.
• stop all other services that are using port 80
• have only one instance of reactapp service, as we don't want the other instance to block the port.