Error with docker-compose

[Fagerinfoco]

Same issue as AgustinPardo and jscalderon65 are reporting:

web_1 | Unable to connect to ES. Retrying in 5 secs...
web_1 | Unable to connect to ES. Retrying in 5 secs...
web_1 | Unable to connect to ES. Retrying in 5 secs...
web_1 | Out of retries. Bailing out...
web_1 | /usr/local/lib/python3.6/dist-packages/requests/init.py:91: RequestsDependencyWarning: urllib3 (1.26.4) or chardet (3.0.4) doesn't match a supported version!
web_1 | RequestsDependencyWarning)

I have also tried to watch the creation through Portainer logs and am seeing this error:

python3: can't open file 'app.py': [Errno 2] No such file or directory

docker-compose.yml
version: "3"
services:
es:
image: docker.elastic.co/elasticsearch/elasticsearch:6.3.2
container_name: es
environment:
- discovery.type=single-node
ports:
- 9200:9200
volumes:
- esdata1:/usr/share/elasticsearch/data
web:
image: bfager27/foodtrucks-web
command: python3 app.py
depends_on:
- es
ports:
- 5000:5000
volumes:
- ./flask-app:/opt/flask-app
volumes:
esdata1:
driver: local

Dockerfile:
//# start from base
FROM ubuntu:18.04

LABEL maintainer="Prakhar Srivastav prakhar@prakhar.me"

//# install system-wide deps for python and node
RUN apt-get -yqq update
RUN apt-get -yqq install python3-pip python3-dev curl gnupg
RUN curl -sL https://deb.nodesource.com/setup_10.x | bash
RUN apt-get install -yq nodejs

//# copy our application code
ADD flask-app /opt/flask-app
WORKDIR /opt/flask-app

//# fetch app specific deps
RUN npm install
RUN npm run build
RUN pip3 install -r requirements.txt

//# expose port
EXPOSE 5000

//# start app
CMD [ "python3", "./app.py" ]