Docker Cmd Exec-Form for Multiple Command Execution
Here Is a Silly Example of Running Multiple Commands via the Cmd Instruction in Shell-Form. I Would Prefer to Use the Exec-Form, but I Don't Know How to...
Here is a silly example of running multiple commands via the CMD instruction in shell-form. I would prefer to use the exec-form, but I don't know how to concatenate the instructions.
shell-form:
CMD mkdir -p ~/my/new/directory/ \
&& cd ~/my/new/directory \
&& touch new.file
exec-form:
CMD ["mkdir","-p","~/my/new/directory/"]
# What goes here?
Can someone provide the equivalent syntax in exec-form?
2 Answers
The short answer is, you cannot chain together commands in the exec form.
&& is a function of the shell, which is used to chain commands together. In fact, when you use this syntax in a Dockerfile, you are actually leveraging the shell functionality.
If you want to have multiple commands with the exec form, then you have do use the exec form to invoke the shell as follows...
CMD ["sh","-c","mkdir -p ~/my/new/directory/ && cd ~/my/new/directory && touch new.file"]
I would argue though that these commands should be execute with at a RUN step rather than CMD.
RUN mkdir -p ~/my/new/directory/ && \
cd ~/my/new/directory && \
touch new.file
Sarah Jenkins is a veteran tech journalist with over 12 years of experience covering artificial intelligence, mobile innovations, and digital ethics. Her insights have appeared in leading technology publications worldwide.
