Consider having capability to install another command that is not natively installed

[naonaonao316]

While I was adding tests using commandunit, one of them requires curl command to be installed.
However, the docker image used for commandunit (You can see it here, which is originated in the image in jq-front).

I also got below error when I was trying to install curl command in the docker image that is launched by commandunit --debug-shell command.

I have no name!@8e93788c6fc1:/$ apt-get install curl E: Could not open lock file /var/lib/dpkg/lock-frontend - open (13: Permission denied) E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), are you root?

If I add sudo to the beginning, I got this.

I have no name!@8e93788c6fc1:/$ sudo apt-get install curl bash: sudo: command not found

I'm not sure whether curl should be natively installed, but at least I'd like to have a capability to install another command required for the test.

[dakusui]

Since the commandunit is a tool to execute test, it is valid to integrate the commands necessary for test execution of a target product in general (as long as it can be considered general enough)
In your case, accessing a Web end-point through curl in a test is a general enough use-case.
So please include the command in Dockerfile, rather than trying to install it during a test execution.