My goal is to run a Docker container that contains crontab, so I want, as a non-root user, to be able to run scheduled crontab jobs. I am running the following Docker image:

FROM openjdk:8
RUN apt-get update && apt-get -y install nano
RUN apt-get update && apt-get -y install cron
RUN service cron start # tried both
RUN cron               # tried both
ENV TZ="Europe/Rome"
RUN useradd -u 8877 myuser
USER myuser
CMD ["tail", "-f", "/dev/null"]

I deploy it in a Docker stack:

...
crontab:
  image: reg/image
  cap_drop:
  - cap_dac_override
deploy:
  mode: replicated
  replicas: 1
  restart_policy:
    condition: any
    delay: 3s
    window: 60s
  placement:
    constraints: [node.role == manager]
  update_config:
    delay: 2s
volumes:
  - v:/my/vol
environment:
  - PUID=8877
  - PGID=8877
...

When I docker exec -it <id> bash as myuser into the container, I execute service cron status and it outputs "cron is running." But if I try to crontab -e, the file I am writing appears with the red error message "Problems with history file". If I try to save it, others errors appear, as "no crontab for myuser - using an empty one touch: cannot touch '/home/myuser/.selected_editor': No such file or directory Unable to create directory /home/myuser/.local/share/nano/: No such file or directory It is required for saving/loading search history or cursor positions."

My goal is to run a Docker container that contains crontab. So I want, as a non-root user, to be able to run scheduled crontab jobs. I am running the following Docker image:

FROM openjdk:8
RUN apt-get update && apt-get -y install nano
RUN apt-get update && apt-get -y install cron
RUN service cron start # tried both
RUN cron               # tried both
ENV TZ="Europe/Rome"
RUN useradd -u 8877 myuser
USER myuser
CMD ["tail", "-f", "/dev/null"]

I deploy it in a Docker stack:

...
crontab:
  image: reg/image
  cap_drop:
  - cap_dac_override
deploy:
  mode: replicated
  replicas: 1
  restart_policy:
    condition: any
    delay: 3s
    window: 60s
  placement:
    constraints: [node.role == manager]
  update_config:
    delay: 2s
volumes:
  - v:/my/vol
environment:
  - PUID=8877
  - PGID=8877
...

When I run docker exec -it <id> bash as myuser into the container, I execute service cron status and it outputs "cron is running." But if I run crontab -e, the file I am writing appears with red error message "Problems with history file". If I try to save it others errors appear such as "no crontab for myuser - using an empty one touch: cannot touch '/home/myuser/.selected_editor': No such file or directory Unable to create directory /home/myuser/.local/share/nano/: No such file or directory It is required for saving/loading search history or cursor positions."