Add type check for the context root in ContentProvider

[shzhou12]

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Complete Description of Additions/Changes:

ccx-ocp-core added a new execution context recently and the context root is not a string but a dictionary. This pull request adds type checks for the context root in class ContentProvider to avoid the TypeError exceptions.

[shzhou12]

The exception detail when executing the insights run command:

  INFO:insights.core.dr:Trying insights.specs.default.DefaultSpecs.redhat_release
  WARNING:insights.core.dr:Traceback (most recent call last):
    File "/builds/ccx/ccx-rules-ocp/.tox/functional-py38/lib/python3.8/site-packages/insights/core/dr.py", line 967, in run
      result = DELEGATES[component].process(broker)
    File "/builds/ccx/ccx-rules-ocp/.tox/functional-py38/lib/python3.8/site-packages/insights/core/dr.py", line 686, in process
      return self.invoke(broker)
    File "/builds/ccx/ccx-rules-ocp/.tox/functional-py38/lib/python3.8/site-packages/insights/core/plugins.py", line 90, in invoke
      return self.component(broker)
    File "/builds/ccx/ccx-rules-ocp/.tox/functional-py38/lib/python3.8/site-packages/insights/core/spec_factory.py", line 569, in __call__
      return self.kind(ctx.locate_path(self.path), root=ctx.root, ds=self, ctx=ctx)
    File "/builds/ccx/ccx-rules-ocp/.tox/functional-py38/lib/python3.8/site-packages/insights/core/spec_factory.py", line 171, in __init__
      self.file_name = os.path.basename(self.path)
    File "/builds/ccx/ccx-rules-ocp/.tox/functional-py38/lib/python3.8/site-packages/insights/core/spec_factory.py", line 112, in path
      return os.path.join(self.root, self.relative_path)
    File "/usr/lib64/python3.8/posixpath.py", line 76, in join
      a = os.fspath(a)
  TypeError: expected str, bytes or os.PathLike object, not dict

[shzhou12]

@xiangce Could you please help to review this pull request?

[ryan-blakley]

@shzhou12 Could you provide more information on this issue, if it's a link to a jira if you'll email it to me? I feel like this is just covering up/ignoring the real issue that needs to be addressed. Because I can't think of a spec that would return a dict for the root or relative path.

[ryan-blakley]

I think this can be closed, as the issue can be stopped by using the parameter added in pr #3434.

[ryan-blakley]

Closing this as the issue was fixed by adding the --no-load-default parameter in 3434.