Add support for dumping request and response in Go generated clients

[dnaeon]

The following change adds a new configuration setting, which
controls whether clients want to dump the HTTP request and response.

Useful when debugging API calls and clients.

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[dnaeon]

CC @antihax, @bvwells, @grokify, @kemokemo, @bkabrda

[wing328]

@dnaeon thanks for the PR. What about using a logger (e.g. https://github.com/google/logger) instead?

[dnaeon]

Hey @wing328,

I've tested it with a logger first, but the results weren't pretty, that's why I've left it using just fmt.Println.

[antihax]

This should really be done with middleware, not in the client directly. Is there a reason it cant be?

[wing328]

I've tested it with a logger first, but the results weren't pretty, that's why I've left it using just fmt.Println.

Can you please elaborate?

[wing328]

FYI. For other clients (e.g. Ruby), we also use a logger for debugging purposes.

[dnaeon]

I've tested it with a logger first, but the results weren't pretty, that's why I've left it using just fmt.Println.

Can you please elaborate?

@wing328 Here's one example.

https://play.golang.org/p/o5LE9R5iCpj

Basically the timestamp of the logger is attached to just the first line of the output, which makes it less pretty, IMO.

Also, I found fmt.Println to be less distractive for my use cases, but I can switch that over to a logger, if you think that's better.

This should really be done with middleware, not in the client directly. Is there a reason it cant be?

@antihax That should work I guess. Can you point me to an example middleware I can lookup?

Thanks!

[antihax]

Here is an example of two chained middleware for the API client.
Setup of the chain LimitedTransport and APICacheTransport.
https://github.com/antihax/evedata/blob/master/internal/apicache/apicache.go#L50

Here are the implementations:
https://github.com/antihax/evedata/blob/master/internal/apicache/limitedTransport.go
https://github.com/antihax/evedata/blob/master/internal/apicache/transport.go#L20

You would create another of these that would dump the request and response.

In the case here you would do something like this:

func (t *DumpTransport) RoundTrip(req *http.Request) (*http.Response, error) {
	reqb, _ := httputil.DumpRequest(req, true)
	res, err:= t.Transport.RoundTrip(req)
	resb, _ := httputil.DumpResponse(res, true)
        ... log the request and response ...
	return res, err
}

[wing328]

Basically the timestamp of the logger is attached to just the first line of the output, which makes it less pretty, IMO.

What about putting a "\n" at the beginning of the log?

[dnaeon]

Here is an example of two chained middleware for the API client.
Setup of the chain LimitedTransport and APICacheTransport.
https://github.com/antihax/evedata/blob/master/internal/apicache/apicache.go#L50

Here are the implementations:
https://github.com/antihax/evedata/blob/master/internal/apicache/limitedTransport.go
https://github.com/antihax/evedata/blob/master/internal/apicache/transport.go#L20

You would create another of these that would dump the request and response.

In the case here you would do something like this:

func (t *DumpTransport) RoundTrip(req *http.Request) (*http.Response, error) {
	reqb, _ := httputil.DumpRequest(req, true)
	res, err:= t.Transport.RoundTrip(req)
	resb, _ := httputil.DumpResponse(res, true)
        ... log the request and response ...
	return res, err
}

@antihax Thanks, that would work.

Basically the timestamp of the logger is attached to just the first line of the output, which makes it less pretty, IMO.

What about putting a "\n" at the beginning of the log?

@antihax, @wing328 I'll leave it to you whether it's worth merging this PR considering that we can have the same thing done with either a middleware or custom roundtripper.

[wing328]

@dnaeon the debug flag in other clients can be used not only for dumping request/response but also other troubleshooting (e.g. object serialization, etc).

so if you're using a logger with the debug flag, I'll be happy to merge this into master.

[dnaeon]

@dnaeon the debug flag in other clients can be used not only for dumping request/response but also other troubleshooting (e.g. object serialization, etc).

so if you're using a logger with the debug flag, I'll be happy to merge this into master.

@wing328, I can take care of updating the PR.

Which logger you'd prefer to have as part of the implementation?

https://github.com/google/logger or the builtin log.Logger?

[wing328]

Please start with the built-in one. Thanks 在 2019年11月23日週六 下午3:49，Marin Atanasov Nikolov <notifications@github.com> 寫道：

…

@dnaeon <https://github.com/dnaeon> the debug flag in other clients can be used not only for dumping request/response but also other troubleshooting (e.g. object serialization, etc). so if you're using a logger with the debug flag, I'll be happy to merge this into master. @wing328 <https://github.com/wing328>, I can take care of updating the PR. Which logger you'd prefer to have as part of the implementation? https://github.com/google/logger or the builtin log.Logger? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#4566?email_source=notifications&email_token=AAHEC5GYHQWUFJ2GI7EZJJLQVDOBHA5CNFSM4JQAIXC2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEE7P24I#issuecomment-557776241>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAHEC5E7Y3XUXR34ZKGHFCDQVDOBHANCNFSM4JQAIXCQ> .

[dnaeon]

@wing328 just pushed a new commit which uses log.Logger.

[wing328]

@dnaeon thanks for the PR, which looks good to me.

[wing328]

@dnaeon when you've time, I wonder if you can file the same PR for go-experimental generator as well. Thank you.

[dnaeon]

@wing328 Sure, here it is #4649