atomic: fix errors in display option

[chuanchang]

atomic install with --display doestn't work, and atomic run still preview the command without --display option, the patch will fix them.

Signed-off-by: Alex Jia ajia@redhat.com

[rhatdan]

@chuanchang We have always been displaying the command before executing. The new code was just to allow a "test" run where it would only display the message but not actually run it.

We could open a discussion on whether we should continue to display the command before executing it.

[chuanchang]

@rhatdan, got it, good to know this, thanks.

[chuanchang]

@rhatdan, there are two questions are mentioned in this PR, except above one, I think we should fix issue for atomic install with --display doestn't work.

[rhatdan]

@chuanchang Could you fix your patch for install --display then and I will merge

@sallyom ^^

[sallyom]

thanks for the fix @chuanchang

from Options: section of 'man atomic install'
--display Display the image's install options and environment variables populated into the install command. The install command will not execute if --display is specified. If --display is not specified the install command will execute.

[chuanchang]

@rhatdan, @sallyom, done, you're welcome :)

[rhatdan]

LGTM

[willmtemple]

@rhatdan This has a test failure due to a runtime exception. There's a code path in which cmd is never set.

In addition atomic install now seems to be mostly broken on images with INSTALL labels.

++ /usr/bin/coverage run --source=./Atomic/ --branch --append atomic install --display -n TEST2 atomic-test-1
Traceback (most recent call last):
  File "atomic", line 306, in <module>
    sys.exit(args.func())
  File "/home/wtemple/Development/atomic/Atomic/atomic.py", line 599, in install
    self.display(cmd)
UnboundLocalError: local variable 'cmd' referenced before assignment

@chuanchang What exactly was the problem with the command prior to this PR? atomic install --display is not supposed to modify the state of the machine. Perhaps the name of the flag is confusing. --dry-run would be better maybe?

[chuanchang]

@willmtemple, oh, I forgot to declare 'cmd' variable before if statement, for the name of the flag, I have no idea, @rhatdan, what do you think? thx

[rhatdan]

I think this is the correct way.

#109