Merge lp:~harlowja/cloud-init/cloud-init-fix-dnf into lp:~cloud-init-dev/cloud-init/trunk

[Joshua Harlow]

Enable usage of DNF for package management

DNF is the new YUM replacement so if it exists
or if its usage is forced try to use it instead
to install packages.

[lp:~harlowja/cloud-init/cloud-init-fix-dnf]

1249. By Joshua Harlow on 2016-07-13

Use util.which and always use dnf if it is around

1250. By Joshua Harlow on 2016-07-13

The os import is no longer needed

[Server Team CI bot (server-team-bot)]

PASSED: Continuous integration, rev:1250
https://server-team-jenkins.canonical.com/job/cloud-init-ci/39/
Executed test runs:
    None: https://server-team-jenkins.canonical.com/job/lp-vote-on-merge/13/console

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review: Approve (continuous-integration)

[Scott Moser (smoser)]

Hello,
Thank you for taking the time to contribute to cloud-init. Cloud-init has moved its revision control system to git. As a result, we are marking all bzr merge proposals as 'rejected'. If you would like to re-submit this proposal for review, please do so by following the current HACKING documentation at http://cloudinit.readthedocs.io/en/latest/topics/hacking.html .

I think this is actually already merged at
https://git.launchpad.net/cloud-init/commit/?id=a3daf184fd4

=== modified file 'cloudinit/distros/rhel.py'
--- cloudinit/distros/rhel.py	2016-06-15 23:11:24 +0000
+++ cloudinit/distros/rhel.py	2016-07-13 00:25:38 +0000
@@ -201,14 +201,22 @@
         if pkgs is None:
             pkgs = []
 
-        cmd = ['yum']
-        # If enabled, then yum will be tolerant of errors on the command line
-        # with regard to packages.
-        # For example: if you request to install foo, bar and baz and baz is
-        # installed; yum won't error out complaining that baz is already
-        # installed.
-        cmd.append("-t")
-        # Determines whether or not yum prompts for confirmation
+        dnf_bin = util.which("dnf")
+        if dnf_bin:
+            LOG.debug('Using DNF for package management')
+            cmd = [dnf_bin]
+        else:
+            LOG.debug('Using YUM for package management')
+            cmd = ['yum']
+            # If enabled, then yum will be tolerant of errors on the command
+            # line with regard to packages.
+            #
+            # For example: if you request to install foo, bar and baz and
+            # baz is installed; yum won't error out complaining that baz
+            # is already installed.
+            cmd.append("-t")
+
+        # Determines whether or not yum/dnf prompts for confirmation
         # of critical actions. We don't want to prompt...
         cmd.append("-y")