[V2V] Add extra error handling for the ConversionHost#run_conversion method

app/models/conversion_host.rb

@@ -144,7 +144,7 @@ def ipaddress(family = 'ipv4')
   def apply_task_limits(path, limits = {})
     connect_ssh { |ssu| ssu.put_file(path, limits.to_json) }
   rescue MiqException::MiqInvalidCredentialsError, MiqException::MiqSshUtilHostKeyMismatch => err
-    raise "Failed to connect and apply limits in file '#{path}' with [#{err.class}: #{err}"
+    raise "Failed to connect and apply limits in file '#{path}' with [#{err.class}: #{err}]"
   rescue JSON::GeneratorError => err
     raise "Could not generate JSON from limits '#{limits}' with [#{err.class}: #{err}]"
   rescue StandardError => err
@@ -154,8 +154,12 @@ def apply_task_limits(path, limits = {})
   def run_conversion(conversion_options)
     result = connect_ssh { |ssu| ssu.shell_exec('/usr/bin/virt-v2v-wrapper.py', nil, nil, conversion_options.to_json) }
     JSON.parse(result)
-  rescue => e
-    raise "Starting conversion failed on '#{resource.name}' with [#{e.class}: #{e}]"
+  rescue MiqException::MiqInvalidCredentialsError, MiqException::MiqSshUtilHostKeyMismatch => err
+    raise "Failed to connect and run conversion using options #{conversion_options} with [#{err.class}: #{err}]"
+  rescue JSON::ParserError
+    raise "Could not parse result data after running virt-v2v-wrapper.py using options: #{conversion_options}. Result was: #{result}."
+  rescue StandardError => err
+    raise "Starting conversion failed on '#{resource.name}' with [#{err.class}: #{err}]"
   end
 
   # Kill a specific remote process over ssh, sending the specified +signal+, or 'TERM'

spec/models/conversion_host_spec.rb

@@ -444,6 +444,36 @@
     end
   end
 
+  context "#run_conversion" do
+    let(:vm) { FactoryBot.create(:vm_openstack) }
+    let(:conversion_host) { FactoryBot.create(:conversion_host, :resource => vm) }
+    let(:conversion_options) { {:foo => 1, :bar => 'hello' } }
+
+    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.run_conversion(conversion_options)).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 result data after running virt-v2v-wrapper.py using "\
+        "options: #{conversion_options}. Result was: bogus."
+      expect { conversion_host.run_conversion(conversion_options) }.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 run conversion using options #{conversion_options}"
+      expect { conversion_host.run_conversion(conversion_options) }.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 = "Starting conversion failed on '#{vm.name}'"
+      expect { conversion_host.run_conversion(conversion_options) }.to raise_error(/#{expected_message}/)
+    end
+  end
+
   context "#get_conversion_state" do
     let(:vm) { FactoryBot.create(:vm_openstack) }
     let(:conversion_host) { FactoryBot.create(:conversion_host, :resource => vm) }