Currently, 95% of the QA commands are executed in the same way: on the
master, based on a command list and with expectancies for succes:

    AssertEqual(StartSSH(master['primary'],
                         utils.ShellQuoteArgs(cmd)).wait(), 0)

The rest 5% are variations on this theme (maybe the command needs to
fail, or the node is different, etc.). Based on this, we can simplify
the code significantly if we abstract the common theme into a new
AssertCommand() function. This saves ~250 lines of code in the QA suite,
around 8% of the entire QA code size.

Additionally, the output was very cryptic before (the famous "QA error:
1 != 0" messages), whereas now we show a clear error message (node,
command, exit code and failure mode).

The patch replaces single quotes with double quotes in all the parts of
the code that I touch; let me know if that's not OK…

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

This would have prevented the bug fixed in the previous patch :(

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

This adds basic qa tests for gnt-os modify

Signed-off-by: René Nussbaumer <rn@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

Also, since Ganeti 2.1 will be compatible with both 10 and 15, change
the OS_API_VERSION constant to be an OS_API_VERSIONS set, and update the
places in the code that used that constat to use something else.

In particular:
  - in the qa for now we just create a fake version 10 OS
  - in the os environment we use the highest common version
    (which means we need to pass in the os to OSEnvironment)
  - when loading an OS any common version will do

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

To my knowledge they're used nowhere and it's at least slightly
confusing to people adding new QA checks.

Reviewed-by: ultrotter

Reviewed-by: iustinp

Reviewed-by: schreiberal

Make the code somewhat smaller. Disable disk failure test for master for now.

Reviewed-by: schreiberal

Reviewed-by: iustinp