Fix grafana_dashboard py2/3 compatibility

[jqueuniet]

SUMMARY

Fix grafana_dashboard Python 2 compatibility

ISSUE TYPE

• Bugfix Pull Request

COMPONENT NAME

grafana_dashboard

ADDITIONAL INFORMATION

Merge request #47708 added a regression with Python 2, causing the following error:

failed: [grafana-infra-000] (item=['node_exporter.json', 'prometheus-infra-000']) => {"changed": false, "item": ["node_exporter.json", "prometheus-infra-000"], "msg": "error : descriptor 'split' requires a 'str' object but received a 'unicode'"}

Issue was the json.loads in the Grafana version check returned a unicode variable, incompatible with str.split.

I switched to using the split method from the returned object, either str.split or unicode.split depending on the type. The integer cast at the end of the function works with either type and normalizes the function output.

I also got the following error testing this fix for Python 3, also in the Grafana version check, and tried to correct it too:

failed: [grafana-infra-000] (item=['node_exporter.json', 'prometheus-infra-000']) => {"changed": false, "item": ["node_exporter.json", "prometheus-infra-000"], "msg": "error : the JSON object must be str, not 'bytes'"}

This time, it was the json.loads that was choking on a bytes object. I added a call to the to_text function to handle this issue, and added a case for UnicodeError in the exception handling.

Some data on my environment:

ansible 2.8.0.dev0 (fix_grafana_py2 7008e1bb47) last updated 2018/11/27 16:42:11 (GMT +200)
  config file = /etc/ansible/ansible.cfg
  configured module search path = ['/home/johann/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/johann/src/ansible/lib/ansible
  executable location = /home/johann/src/ansible/bin/ansible
  python version = 3.7.1 (default, Oct 22 2018, 10:41:28) [GCC 8.2.1 20180831]

[ansibot]

Hi @jqueuniet, thank you for submitting this pull-request!

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[remyleone]

@pilou- Could you review?

[ansibot]

cc @seuf
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[seuf]

I've tried both python2.7 and python 3 and it worked for me.
Thanks for your contribution 😃
LGTM

[gundalow]

rebuild_merge

Once merged please raise a backport PR including a changelog/fragment