My docker container's crontab doesn't seem to be running - docker

Question

I'm fairly new to Docker so please bear with me:
I have a collection of 5 java applications that I'm trying to run inside a docker container (via cronjobs inside the container).
I've created my Dockerfile and a docker-compose file as well. I'm able to launch my docker container and I'm able to manually run my applications inside the container. The problem is, it doesn't seem to be running my stuff via the cron. To test, I added a cron entry to echo hello world to a file every minute. It doesn't seem to run. Here are my files:
Dockerfile
FROM ubuntu:latest
ENV LANG C.UTF-8
ENV TZ=EST
ENV DEBIAN_FRONTEND=noninteractive
RUN mkdir -p /wrds/ingesters/logs
WORKDIR /wrds/ingesters
RUN apt-get update && apt-get install -y \
tzdata \
apt-utils \
cron \
default-jdk \
bash \
postgresql \
bsd-mailx \
postfix \
vim
COPY *.jar /wrds/ingesters/
COPY run* /wrds/ingesters/
COPY *.properties /wrds/ingesters/
ADD ingester_cron /etc/cron.d/root
RUN chmod 0644 /etc/cron.d/root
RUN touch /var/log/cron.log
RUN crontab /etc/cron.d/root
RUN mkfifo /var/spool/postfix/public/pickup
RUN echo 'alias ll="ls -la"' >> ~/.bashrc
RUN echo 'stty erase ^H' >> ~/.bashrc
CMD cron -L15 && tail -f /var/log/cron.log
docker-compose.yml (anything in all caps is edited out by me for security issues)
version: '3.5'
services:
wrds_hylo_db_ingesters:
image: HOSTNAME/wrds/CONTAINERNAME
container_name: CONTAINERNAME
restart: always
env_file: env.dev-v2
volumes:
- /ingester_logs:/wrds/ingesters/logs
pid: host
ingester_cron
0 17 * * 1 root /wrds/ingesters/run_script1
0 20 * * 1 root /wrds/ingesters/run_script2
0 23 * * 1 root /wrds/ingesters/run_script3
0 2 * * 2 root /wrds/ingesters/run_script4
* * * * * root echo "Hello World" >> /var/log/cron.log 2>&1
When I run my docker container and ssh in, I get the following:
root#1b0d719feada:/var/log# service cron status
* cron is running
crontab -l
0 17 * * 1 root /wrds/ingesters/run_script1
0 20 * * 1 root /wrds/ingesters/run_script2
0 23 * * 1 root /wrds/ingesters/run_script3
0 2 * * 2 root /wrds/ingesters/run_script4
* * * * * root echo "Hello World" >> /var/log/cron.log 2>&1
Any help would be appreciated!

Answer 1

Maybe you take a look at the logs. Maybe you can see more of what your crons are doing.
Cron: */3 * * * * YOUR-CRON_BLABLA > /dev/stdout logs to the container output
ex.: docker-compose logs -f
I load my cron jobs like this:
COPY ./MY-CRON-FILE.cron /
RUN crontab /tmp/MY-CRON-FILE.cron
...
Depending on the application also sometimes with a certain user:
RUN crontab -u MY-USER /MY-CRON-FILE.cron