Run script on docker init

Dockerfile

FROM ubuntu

COPY script.sh /tmp/script.sh
RUN chmod +x /tmp/script.sh

CMD ["bash", "-c", "/tmp/script.sh"]

log.txt

 docker build -t local/test .
Sending build context to Docker daemon  4.096kB
Step 1/4 : FROM ubuntu
 ---> ba6acccedd29
Step 2/4 : COPY script.sh /tmp/script.sh
 ---> f3f4498bf017
Step 3/4 : RUN chmod +x /tmp/script.sh
 ---> Running in fca78ee43c96
Removing intermediate container fca78ee43c96
 ---> 60e3a72ae0a9
Step 4/4 : CMD ["bash", "-c", "/tmp/script.sh"]
 ---> Running in e15ae71ebfce
Removing intermediate container e15ae71ebfce
 ---> 6c136346a3af
Successfully built 6c136346a3af
Successfully tagged local/test:latest

 docker run local/test
hello!
Sat Mar 12 03:02:53 UTC 2022
This is a message

script.sh

#!/bin/bash
echo "hello!"
echo "This is a message" > aa
echo $(date)
cat aa