hello-world.evil does not work as an example of the app confinement

[Nobuto Murata]

hello-world.evil succeeds, it should work as an example of blocked by the confinement.

(RaspberryPi2)ubuntu@snappy:~$ hello-world.evil
Hello Evil World!
This example demonstrates the app confinement
You should see a permission denied error next
If you see this line the confinement is not working correctly, please file a bug

(RaspberryPi2)ubuntu@snappy:~$ cat /tmp/myevil.txt
Haha

(RaspberryPi2)ubuntu@snappy:~$ snappy list -v
Name Date Version Developer
ubuntu-core 2015-06-11 3 ubuntu*
ubuntu-core 2015-06-11 3 ubuntu
hello-world 2015-06-19 1.0.17 canonical*
webdm 2015-06-11 0.9 *
pi2 2015-06-11 0.13 *

[Jamie Strandboge (jdstrand)]

This was introduced with the new /tmp handling. See:
echo "Haha" > /tmp/myevil.txt

A simple fix is to use /var/tmp/myevil.txt instead.

[Leo Arias (elopio)]

Reproduced on beagle bone black rev C 15.04 edge #94.
We need a test for this, should be easy to write as part of the selftests.

[Jamie Strandboge (jdstrand)]

Fixed in 1.0.18

$ sudo snappy update hello-world.canonical
Installing hello-world (1.0.18)
Starting download of hello-world
21.60 KB / 21.60 KB [==========================================] 100.00 % 82.91 KB/s
Done
Name Date Version Developer
hello-world 1-01-01 1.0.18 canonical
$ hello-world.evil
Hello Evil World!
This example demonstrates the app confinement
You should see a permission denied error next
/apps/hello-world.canonical/1.0.18/bin/evil: 9: /apps/hello-world.canonical/1.0.18/bin/evil: cannot create /var/tmp/myevil.txt: Permission denied