I had difficulty in understanding the difference between CMD and ENTRYPOINT in Dockerfile before I did the below experiment. Hope this will help someone like me who cannot understand the difference from the documentation or stackoverflow.
Consider the below docker file
[ythulasi@YTHULASI-M-C341 01.BusyboxWithCMD]$ cat Dockerfile FROM busybox:latest CMD ["cat", "/etc/passwd"]
Let's build an image and call it busy_cmd_image
[ythulasi@YTHULASI-M-C341 01.BusyboxWithCMD]$ docker build -t busy_cmd_image . Sending build context to Docker daemon 2.048 kB Step 1 : FROM busybox:latest ---> 2b8fd9751c4c Step 2 : CMD cat /etc/passwd ---> Using cache ---> e4df0d0c0d67 Successfully built e4df0d0c0d67
Now, we ...more ...