fix #230

[agcandil]

Fix PR: 231
Closes #230
Summary
The object __node_exporter_current_version_output.stderr_lines is an empty list which causes the following bug in the tasks/main.yml/install.yml conditional. This bug happens only after provisioning the role for the first time.

TASK [cloudalchemy.node_exporter : Create the node_exporter group] ***********************************************************
fatal: [infra-mon-1]: FAILED! => 
  msg: |-
    The conditional check '( not __node_exporter_is_installed.stat.exists ) or ( __node_exporter_current_version_output.stderr_lines[0].split(" ")[2] != node_exporter_version ) or ( node_exporter_binary_local_dir | length > 0 )' failed. The error was: error while evaluating conditional (( not __node_exporter_is_installed.stat.exists ) or ( __node_exporter_current_version_output.stderr_lines[0].split(" ")[2] != node_exporter_version ) or ( node_exporter_binary_local_dir | length > 0 )): list object has no element 0
  
    The error appears to be in '/home/dan/.ansible/roles/cloudalchemy.node_exporter/tasks/install.yml': line 2, column 3, but may
    be elsewhere in the file depending on the exact syntax problem.
  
    The offending line appears to be:
  
    ---
    - name: Create the node_exporter group
      ^ here

Added backward compatiblity checking stdout and stderr

[adamcstephens]

I can confirm this fixes the issue for me.

[SuperQ]

LGTM, thanks

[SuperQ]

If you rebase the change against HEAD, it should fix the test.

[agcandil]

Thanks, Tests fixed!!!

[vosdev]

@SuperQ Can you release a new version? The role is basically unusable until this PR is merged.

[rgdev]

Any updates on an eventual 2.0.1 release with this hotfix ? Role is unusable right now without manual yaml editing :/

[ben-wallis]

You can work around the lack of an official release by using the following in requirements.yml to install the role from the latest git commit:

  - src: git+https://github.com/cloudalchemy/ansible-node-exporter
    version: 5c049ffdd1918752d9d078193c2ddd003d5332ac

You'll also need to use ansible-node-exporter instead of cloudalchemy.node_exporter when importing the role to a playbook as the role name is different when sourced from git.

[SuperQ]

Sorry, I've been behind on debugging some issues with the release process.