Race condition when later modules override files from earlier modules

[blee]

Files that get overridden by later modules in a recipe should never get installed to the filesystem.

For example, consider the sudoers file.

Recipe "base" does not allow the use of sudo:

base/usr/local/etc/sudoers

But recipe "sudo-wheel" allows members of group wheel to run sudo:

sudo-wheel/usr/local/etc/sudoers

And a sample recipe r:

base
sudo-wheel

Running 'confman commit' on a machine using recipe r will leave the machine in a broken state, since the base sudoers file will prevent confman commit from proceeding.

This may have rather unexpected effects for files other than sudoers as well (e.g. nsswitch.conf).

[ccowart]

(In [543]) WIP: Fixing race condition.

Overall design change:

• Commit modules in _reverse_ order
• Keep a list of "committed" files and don't re-commit if we encounter the same filesystem path in a later module

I need some help reviewing this change, especially as it relates to the
install operation; I'm not convinced the implementation is complete yet.

See #120.

[ccowart]

(In [544]) Reverting change; accidentally went into the 1.9 branch instead of trunk.

See #120.

[ccowart]

(In [545]) WIP: Fixing race condition. And committing to the right place (trunk).

Overall design change:

• Commit modules in _reverse_ order
• Keep a list of "committed" files and don't re-commit if we encounter the same filesystem path in a later module

I need some help reviewing this change, especially as it relates to the
install operation; I'm not convinced the implementation is complete yet.

See #120.

[ccowart]

(In [546]) Have to use whole-line matching to prevent substring matches.

See #120.

[blee]

(In [547]) Set statefile in confman inst and shift the right number of variables
in conf_install for function signature change.

See #120

[blee]

(In [548]) Also reverse the recipe in confaudit for consistency.

See #120

[blee]

(In [549]) Move the file conf_get_prop calls in conf_rollout into the conditional
to be consistent with the directory calls. This is also a minor
performance optimization when a file is duplicated in a large number
of modules.

See #120

[blee]

(In [550]) Also reverse the recipe in confsync.

See #120

[blee]

(In [551]) Also add statefile creation to confman audit.

See #120

[blee]

(In [552]) Add debug messages to indicate when files and directories are being
ignored because a higher-priority module already installed them.

See #120

[blee]

(In [553]) Correct typo in variable name.

See #120

[blee]

(In [568]) Merge fix for #120 into confman-1.9.

Closes #120