fixed issue 1716: No third party error handling in loading plugin RES…

[candysmurf]

Fixes #1716

Summary of changes:

• Added default loading plugin error response

Testing done:

• small, medium and legacy

@intelsdi-x/snap-maintainers

[mkleina]

Tested your changes (regenerated client-go and CLI) and it seems that go-swagger have some bug (I am using latest swagger release 0.11.0).

When no response code provided, default response code is 200, so the client returns LoadPluginDefault{} type (load_plugin_responses.go):

...
default:
    result := NewLoadPluginDefault(response.Code())
    if err := result.readResponse(response, consumer, o.formats); err != nil {
        return nil, err
    }
    if response.Code()/100 == 2 {
        return result, nil <---------------- HERE
    }
    return nil, result
}

but in LoadPlugin method it casts all results to LoadPluginCreated{} (plugins_client.go):

func (a *Client) LoadPlugin(params *LoadPluginParams, authInfo runtime.ClientAuthInfoWriter) (*LoadPluginCreated, error) {
	// TODO: Validate the params before sending
	if params == nil {
		params = NewLoadPluginParams()
	}

	result, err := a.transport.Submit(&runtime.ClientOperation{
		ID:                 "loadPlugin",
		Method:             "POST",
		PathPattern:        "/plugins",
		ProducesMediaTypes: []string{"application/json"},
		ConsumesMediaTypes: []string{"multipart/form-data"},
		Schemes:            []string{"http", "https"},
		Params:             params,
		Reader:             &LoadPluginReader{formats: a.formats},
		AuthInfo:           authInfo,
		Context:            params.Context,
		Client:             params.HTTPClient,
	})
	if err != nil {
		return nil, err
	}
	return result.(*LoadPluginCreated), nil <--------------- HERE
}

In result, when something go wrong, CLI will throw:

panic: interface conversion: interface {} is *plugins.LoadPluginDefault, not *plugins.LoadPluginCreated

goroutine 1 [running]:
github.com/intelsdi-x/snap-cli/vendor/github.com/intelsdi-x/snap-client-go/client/plugins.(*Client).LoadPlugin(0xc42042df60, 0xc4200a4f00, 0x0, 0x0, 0x0, 0xbf72e0, 0x1)
        /home/mkleina/workspace/go/src/github.com/intelsdi-x/snap-cli/vendor/github.com/intelsdi-x/snap-client-go/client/plugins/plugins_client.go:209 +0x39a
github.com/intelsdi-x/snap-cli/snaptel.loadPlugin(0xc4200949a0, 0x0, 0x0)
        /home/mkleina/workspace/go/src/github.com/intelsdi-x/snap-cli/snaptel/plugin.go:75 +0xa99
github.com/intelsdi-x/snap-cli/vendor/github.com/urfave/cli.HandleAction(0x8a7400, 0x964a90, 0xc4200949a0, 0xc42009a000, 0x0)
        /home/mkleina/workspace/go/src/github.com/intelsdi-x/snap-cli/vendor/github.com/urfave/cli/app.go:490 +0xd4
github.com/intelsdi-x/snap-cli/vendor/github.com/urfave/cli.Command.Run(0x944b0b, 0x4, 0x0, 0x0, 0x0, 0x0, 0x0, 0x962691, 0x76, 0x0, ...)
        /home/mkleina/workspace/go/src/github.com/intelsdi-x/snap-cli/vendor/github.com/urfave/cli/command.go:210 +0xb6e
github.com/intelsdi-x/snap-cli/vendor/github.com/urfave/cli.(*App).RunAsSubcommand(0xc4200fba00, 0xc420094000, 0x0, 0x0)
        /home/mkleina/workspace/go/src/github.com/intelsdi-x/snap-cli/vendor/github.com/urfave/cli/app.go:379 +0xacf
github.com/intelsdi-x/snap-cli/vendor/github.com/urfave/cli.Command.startApp(0x946778, 0x6, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
        /home/mkleina/workspace/go/src/github.com/intelsdi-x/snap-cli/vendor/github.com/urfave/cli/command.go:298 +0x8fa
github.com/intelsdi-x/snap-cli/vendor/github.com/urfave/cli.Command.Run(0x946778, 0x6, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
        /home/mkleina/workspace/go/src/github.com/intelsdi-x/snap-cli/vendor/github.com/urfave/cli/command.go:98 +0x13f3
github.com/intelsdi-x/snap-cli/vendor/github.com/urfave/cli.(*App).Run(0xc4200fb380, 0xc42000ea00, 0x4, 0x4, 0x0, 0x0)
        /home/mkleina/workspace/go/src/github.com/intelsdi-x/snap-cli/vendor/github.com/urfave/cli/app.go:255 +0x76f
main.main()
        /home/mkleina/workspace/go/src/github.com/intelsdi-x/snap-cli/main.go:49 +0x376

[candysmurf]

@mkleina, thanks for the review. May I know the steps to reproduce the error you had?