Add more robust error handling to ConversionHost#get_conversion_state

app/models/conversion_host.rb

@@ -145,17 +145,18 @@ def kill_process(pid, signal = 'TERM')
  false
  end
 
- # Get the conversion state by reading from a remote json file at +path+
- # and return the parsed data.
- #--
- # TODO: This should be more clear on failure, since it could fail because
- # it's not found or because the contents were invalid.
+ # Retrieve the conversion state information from a remote file as a stream.
+ # Then parse and return the stream data as a hash using JSON.parse.
  #
  def get_conversion_state(path)
  json_state = connect_ssh { |ssu| ssu.get_file(path, nil) }
  JSON.parse(json_state)
- rescue => e
- raise "Could not get state file '#{path}' from '#{resource.name}' with [#{e.class}: #{e}"
+ rescue MiqException::MiqInvalidCredentialsError, MiqException::MiqSshUtilHostKeyMismatch => err
+ raise "Failed to connect and retrieve conversion state data from file '#{path}' with [#{err.class}: #{err}"
+ rescue JSON::ParserError
+ raise "Could not parse conversion state data from file '#{path}': #{json_state}"
+ rescue StandardError => err
+ raise "Error retrieving and parsing conversion state file '#{path}' from '#{resource.name}' with [#{err.class}: #{err}"
  end
 
  # Get and return the contents of the remote conversion log at +path+.

spec/models/conversion_host_spec.rb

@@ -309,4 +309,33 @@
  expect(conversion_host_vm.verify_credentials('v2v')).to be_truthy
  end
  end
+
+ context "#get_conversion_state" do
+ let(:vm) { FactoryBot.create(:vm_openstack) }
+ let(:conversion_host) { FactoryBot.create(:conversion_host, :resource => vm) }
+ let(:path) { 'some_path' }
+
+ it "works as expected if the connection is successful and the JSON is valid" do
+ allow(conversion_host).to receive(:connect_ssh).and_return({:alpha => {:beta => 'hello'}}.to_json)
+ expect(conversion_host.get_conversion_state(path)).to eql('alpha' => {'beta' => 'hello'})
+ end
+
+ it "works as expected if the connection is successful but the JSON is invalid" do
+ allow(conversion_host).to receive(:connect_ssh).and_return('bogus')
+ expected_message = "Could not parse conversion state data from file '#{path}': bogus"
+ expect { conversion_host.get_conversion_state(path) }.to raise_error(expected_message)
+ end
+
+ it "works as expected if the connection is unsuccessful" do
+ allow(conversion_host).to receive(:connect_ssh).and_raise(MiqException::MiqInvalidCredentialsError)
+ expected_message = "Failed to connect and retrieve conversion state data from file '#{path}'"
+ expect { conversion_host.get_conversion_state(path) }.to raise_error(/#{expected_message}/)
+ end
+
+ it "works as expected if an unknown error occurs" do
+ allow(conversion_host).to receive(:connect_ssh).and_raise(StandardError)
+ expected_message = "Error retrieving and parsing conversion state file '#{path}' from '#{vm.name}'"
+ expect { conversion_host.get_conversion_state(path) }.to raise_error(/#{expected_message}/)
+ end
+ end
 end