What happens to entrypoint of Docker parent image when child defines another one?

inheritance docker entry-point
Bernhard picture Bernhard · Nov 14, 2016 · Viewed 13k times · Source

Let's say I've got the Docker image parent built by this Dockerfile:

FROM ubuntu
ENTRYPOINT ["parent-entry"]

Now I inherit from this parent image in my child image built with this code:

FROM parent
ENTRYPOINT ["child-entry"]

As far as I have tested it the entrypoint of the child image overwrites the one in the parent image.

But since I am new to Docker I am not sure about this. My research also hasn't yet resulted in a satisfying answer. So is the assumption above correct?

Answer

user2915097 picture user2915097 · Nov 14, 2016

The last entrypoint is used, only the last one.

You can check, put several lines with different ENTRYPOINT in your Dockerfile, and check what happens.

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