podman - How to Start a Process in a Containerfile? - process

Question

I have put a script with an endless loop inside a Containerfile.
When I go inside the container and run that script in the background I can see that the process is running by doing a ps -ef.
But when I try to start the process inside the Containerfile it is not running, even though the podman build and podman run commands are without error.
I am using rootless podman.
This is my Containerfile:
$ cat Containerfile
FROM alpine
RUN apk update
RUN apk add vim
RUN apk add bash
COPY ./useless_process.sh /home
RUN bash /home/useless_process.sh &
# how to build:
# podman build . -t "manualpihimage"
# how to run:
# podman run -it --name "manualpihcontainer" manualpihimage
I have also tried using the CMD and the ENTRYPOINT commands but the process did not start.
The expectation was that the process would run in the background.

Answer 1

I have tried it with Containerfile as follows. Note that I removed the useless & - makes no sense in the context of the container and used CMD because we don't want to run it while building the image but when we start the container.
FROM alpine
RUN apk update
RUN apk add vim
RUN apk add bash
COPY ./useless_process.sh /home
CMD bash /home/useless_process.sh
I created useless_process.sh with:
#!/bin/sh
while `/bin/true`; do
date
sleep 1
done
Then podman build . -t=image1 and podman run -d --name=container1 image1 to start it detached.
$ podman ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
0744f29bec7c localhost/image1:latest /bin/sh -c bash /... 22 seconds ago Up 23 seconds ago container1
And we can see our useless process is running
$ podman exec -it container1 /bin/sh
/ # ps
PID USER TIME COMMAND
1 root 0:00 bash /home/useless_process.sh
188 root 0:00 /bin/sh
197 root 0:00 sleep 1
198 root 0:00 ps