docker container nginx start but keeps hanging - bash

Question

my dockerfile:
FROM AWS_ECR_IMAGE
RUN apt-get update && apt-get install -y \
cron \
python-dev \
git \
zlib1g-dev \
libffi-dev \
libssl-dev \
autotools-dev \
automake \
libbz2-dev \
libaio-dev \
libsasl2-dev \
python-pip
RUN pip install boto boto3 awscli
# Install Nginx.
RUN \
add-apt-repository -y ppa:nginx/stable && \
apt-get update && \
apt-get install -y nginx && \
rm -rf /var/lib/apt/lists/* && \
echo "\ndaemon off;" >> /etc/nginx/nginx.conf && \
chown -R www-data:www-data /var/lib/nginx
# Define mountable directories.
VOLUME ["/etc/nginx/sites-enabled", "/etc/nginx/certs", "/etc/nginx/conf.d", "/var/log/nginx", "/var/www/html"]
# Define working directory.
WORKDIR /etc/nginx
# Define default command.
CMD ["nginx"]
COPY nginx_conf /etc/nginx/sites-available/default
# Start service, replace server name, update web ui
COPY main.sh /opt/annotation-pipeline-docs/main.sh
RUN chmod 0755 /opt/annotation-pipeline-docs/main.sh
ENTRYPOINT [ "sh", "-c", "/opt/annotation-pipeline-docs/main.sh" ]
# Expose ports.
EXPOSE 80
And my entrypoint bash file (I need to update the server name first when the container runs) is:
#!/bin/bash -e
/usr/local/bin/aws s3 sync s3://${S3_Bucket}/docs/${ENVIRONMENT}/HEAD/ /var/www/html/
if [ "$ENVIRONMENT" == "prod" ]
then
sed -i.bak "s/REPLACE_ME/example.com/g" /etc/nginx/sites-available/default
else
sed -i.bak "s/REPLACE_ME/example-$ENVIRONMENT.com/g" /etc/nginx/sites-available/default
fi
nginx
while true; do
sleep 60
echo "s3 sync again:"
/usr/local/bin/aws s3 sync s3://${S3_Bucket}/docs/${ENVIRONMENT}/HEAD/ /var/www/html/
done
The issue is when
nginx
runs, it will hanging forever in the terminal:
and the while loop will never get called. Anyone know why is hanging and how to resolve it? Please help, tks in advanced.

Answer 1

The reason for my issue is waiting for the traffic, the while loop will never get called until Nginx start free the bash. However, Nginx will be running in the foreground and not release the focus.
The solution I tried is instead of letting Nginx running as a foreground service, I changed it run in the background. Since this is the only service in my container, should have no problem to do it.
the code changed is simply removed below line in my dockerfile:
echo "\ndaemon off;" >> /etc/nginx/nginx.conf
which will make Nginx as a foreground service