Waggle sign API server

[kompotkot]

Handle API requests for batch sign

Example of API request:

{
    "chain_id": 80001,
    "dropper": "0x4ec36E288E1b5d6914851a141cb041152Cf95328",
    "signer": "0x123c51488a18fc75d3b8993743f3c132316952c8",
    "requests": [
        {
            "dropId": "2",
            "requestID": "5",
            "claimant": "0x000000000000000000000000000000000000dEaD",
            "blockDeadline": "40000000",
            "amount": "3000000000000000000"
        },
        {
            "dropId": "2",
            "requestID": "6",
            "claimant": "0x000000000000000000000000000000000000dEaD",
            "blockDeadline": "40000000",
            "amount": "3000000000000000000"
        }
    ]
}

Example of response:

{
    "chain_id": 80001,
    "dropper": "0x4ec36E288E1b5d6914851a141cb041152Cf95328",
    "signer": "0x123c51488a18fc75d3b8993743f3c132316952c8",
    "sensible": false,
    "requests": [
        {
            "dropId": "2",
            "requestID": "5",
            "claimant": "0x000000000000000000000000000000000000dEaD",
            "blockDeadline": "40000000",
            "amount": "3000000000000000000",
            "signature": "1165f3f1edba760f570a833891ef238c9e40d2e2d1c6d66ab39904v1934c4bb9342e463bd24e0464cceb66a91ea96a48965bb7603d59dc6b859f1112d077a5e41b",
            "signer": "0x123c51488a18fc75d3b8993743f3c132316952c8"
        },
        {
            "dropId": "2",
            "requestID": "6",
            "claimant": "0x000000000000000000000000000000000000dEaD",
            "blockDeadline": "40000000",
            "amount": "3000000000000000000",
            "signature": "85127edfac02da74776d761f230dc8d1c361ec8fb400881224d8e6001b00b17326048930b0b6e4f03ce407993e12399f80b325cc0be075fad855a2c6168f3b221c",
            "signer": "0x123c51488a18fc75d3b8993743f3c132316952c8"
        }
    ]
}

[kompotkot]

Resolves #11

[kompotkot]

@bugout-dev check

• First merge PR Release build binaries #10

[zomglings]

I don't like availableSigners global variable. Left a few other comments and suggestions.

[zomglings]

Is this necessary?

[kompotkot]

Yes, if path will be passed acidently with trailing slash, like --config ~/config.json/

[zomglings]

I prefer to use:

configTemp := []ServerSignerConfig{}
unmarshalErr := json.Unmarshal(rawBytes, &configTemp)

This is the pattern we use everywhere else:

$ git grep Unmarshal
bugout.go:              parseErr := json.Unmarshal([]byte(result.Content), &reports[i])
cmd.go:                         parseErr := json.Unmarshal(batchRaw, &batch)
cmd.go:                                 rowParseErr := json.Unmarshal(jsonString, &batch[i])
cmd.go:                 parseErr := json.Unmarshal(messagesRaw, &messages)
moonstream.go:  unmarshalErr := json.Unmarshal(responseBody, &contracts)
moonstream.go:  unmarshalErr := json.Unmarshal(responseBody, &callRequests)
server.go:      err = json.Unmarshal(body, &req)
settings.go:    err = json.Unmarshal(rawBytes, configTemp)

[zomglings]

Two things:

1. Reference passed in json.Unmarshal call rather than declaring variable to be the reference.
2. Create a new error for unmarshalling to make the code more readable - unmarshalErr instead of err.

[kompotkot]

I used this, because nodebalancer, monitoring, etc code written in this way. If it is important, I can follow as you wish.

[kompotkot]

Also I am using err because:

func abc(someInts []*int) (int, error) {
  var num *int
  for _, si := range someInts {
    // Here I forced to use `:=` but I want to be asure to use variable `num` scope from func `abc`
    num, numErr := someOperation(si)
     ...
  }
}

So I prefer this code:

func abc(someInts []*int) (int, error) {
  var num *int
  var err error
  for _, si := range someInts {
    num, err = someOperation(si)
     ...
  }
}

[zomglings]

Can we rename it simpler? func Serve(...) error {}?

[kompotkot]

For me its is not clear naming, but ok

[zomglings]

This is the only big problem I have with this PR. Why does this need to be a global variable?

Can't you pass it as an argument to the server?

This should definitely be an argument to ServerRun(host string, port int, availableSigners map[string]AvailableSigner).

You can create a WaggleServer struct and define the handlers on that struct if you want, so that they have access to the availableSigners member.

[zomglings]

We should avoid these kind of global variables. It limits how waggle can be used (e.g. you can't instantiate multiple waggle servers in the same process)`.

[kompotkot]

Problem not in passing to ServerRun but in passing variable in each mux

serveMux := http.NewServeMux()
serveMux.HandleFunc("/ping", pingRoute)
serveMux.HandleFunc("/sign/dropper", signDropperRoute)

[kompotkot]

Not sure how I ll pass in signDropperRoute

[zomglings]

Maybe better to have:

• waggle server configure (replacing waggle accounts config)
• waggle server run

[zomglings]

lgtm