Teller

Setup project

Prerequisites

• Have go1.8+ installed
• Have GOPATH env set
• Have btcd started
• Have skycoin node started

Summary of setup for development without btcd or skycoind

# Generate btc_addresses.json file. 'foobar' is an arbitrary seed, and 10 is an arbitrary number of addresses to generate
go run cmd/tool/tool.go -json newbtcaddress foobar 10 > /tmp/btc_addresses.json

# Run proxy, a pubkey will be printed to stdout, copy it
go run cmd/proxy/proxy.go

# In a new terminal, run teller in dummy mode, provide pubkey from proxy stdout, point addresses to addr file
cd cmd/teller/
go run teller.go -proxy-pubkey=<proxy pubkey> -dummy -btc-addrs=/tmp/btc_addresses.json

Proxy API is available on localhost:7071. API has two methods, /api/bind and /api/status, with one query arg skyaddr, e.g.:

wget http://localhost:7071/api/bind?skyaddr=<skycoin addr>

Start teller-proxy

Note: the proxy must be run from the repo root, in order to serve static content from ./web/dist

make proxy

Once the proxy starts, it will show a pubkey value in the log. Use this for the -proxy-pubkey argument in teller.

18:28:49 proxy.go:33: Pubkey: 03583bf0a6cbe7048023be5475aca693e192b4b5570bcc883c50f7d96f0a996eda

Start teller

Install skycoin-cli

make install-skycoin-cli

add pregenerated bitcoin deposit address list in btc_addresses.json.

{
    "btc_addresses": [
        "1PZ63K3G4gZP6A6E2TTbBwxT5bFQGL2TLB",
        "14FG8vQnmK6B7YbLSr6uC5wfGY78JFNCYg",
        "17mMWfVWq3pSwz7BixNmfce5nxaD73gRjh",
        "1Bmp9Kv9vcbjNKfdxCrmL1Ve5n7gvkDoNp"
    ]
}

use tool to pregenerate bitcoin address list:

cd cmd/tool
go run tool.go -json newbtcaddress $seed $num

Example:

go run tool.go -json newbtcaddress 12323 3

2Q5sR1EgTWesxX9853AnNpbBS1grEY1JXn3
2Q8y3vVAqY8Q3paxS7Fz4biy1RUTY5XQuzb
216WfF5EcvpVk6ypSRP3Lg9BxqpUrgBJBco

generate json file Example:

go run tool.go -json newbtcaddress 12323 3 > new_btc_addresses.json

teller's config is managed in config.json, need to set the wallet_path in skynode field to an absolute path of skycoin wallet file, and set up the btcd config in btc_rpc field, including server address, username, password and absolute path to the cert file.

config.json:

{
    "proxy_address": "127.0.0.1:7070",
    "reconnect_time": 5,
    "dial_timeout": 5,
    "ping_timeout": 5,
    "pong_timeout": 10,
    "exchange_rate": 500,
    "skynode": {
        "rpc_address": "127.0.0.1:6430",
        "wallet_path": "absolute path to the wallet file"
    },
    "btc_scan": {
        "check_period": 20,
        "deposit_buffer_size": 1024
    },
    "btc_rpc": {
        "server": "127.0.0.1:8334",
        "user": "",
        "pass": "",
        "cert": "absolute path to rpc cert file"
    },
    "sky_sender": {
        "request_buffer_size": 1024
    }
}

run teller service

go run teller.go -proxy-pubkey=$the_pubkey_of_proxy

Service apis

The HTTP API service is provided by the proxy and serve on port 7071 by default.

The API returns JSON for all 200 OK responses.

If the API returns a non-200 response, the response body is the error message, in plain text (not JSON).

Bind

Method: POST
Accept: application/json
Content-Type: application/json
URI: /api/bind
Request Body: {
    "skyaddr": "..."
}

Binds a skycoin address to a BTC address. A skycoin address can be bound to multiple BTC addresses. The default maximum number of bound addresses is 5.

Example:

curl -H  -X POST "Content-Type: application/json" -d '{"skyaddr":"..."}' http://localhost:7071/api/bind

response:

{
    "btc_address": "1Bmp9Kv9vcbjNKfdxCrmL1Ve5n7gvkDoNp"
}

Status

Method: GET
Content-Type: application/json
URI: /api/status
Query Args: skyaddr

Returns statuses of a skycoin address.

Since a single skycoin address can be bound to multiple BTC addresses the result is in an array. The default maximum number of BTC addresses per skycoin address is 5.

We cannot return the BTC address for security reasons so they are numbered and timestamped instead.

Possible statuses are:

• waiting_deposit - Skycoin address is bound, no deposit seen on BTC address yet
• waiting_send - BTC deposit detected, waiting to send skycoin out
• waiting_confirm - Skycoin sent out, waiting to confirm the skycoin transaction
• done - Skycoin transaction confirmed

Example:

curl http://localhost:7071/api/status?skyaddr=t5apgjk4LvV9PQareTPzWkE88o1G5A55FW

response:

{
    "statuses": [
        {
            "seq": 1,
            "update_at": 1501137828,
            "status": "done"
        },
        {
            "seq": 2,
            "update_at": 1501128062,
            "status": "waiting_deposit"
        },
        {
            "seq": 3,
            "update_at": 1501128063,
            "status": "waiting_deposit"
        },
    ]
}

Code linting

make install-linters
make lint

Run tests

make test

Database structure

Bucket: used_btc_address
File: btcaddrs/store.go

Maps: `btcaddr -> ""`
Note: Marks a btc address as used

Bucket: exchange_meta
File: exchange/store.go

Note: unused

Bucket: deposit_info
File: exchange/store.go

Maps: btcTx[%tx:%n] -> exchange.DepositInfo
Note: Maps a btc txid:seq to exchange.DepositInfo struct

Bucket: bind_address
File: exchange/store.go

Maps: btcaddr -> skyaddr
Note: Maps a btc addr to a sky addr

Bucket: sky_deposit_seqs_index
File: exchange/store.go

Maps: skyaddr -> [btcaddrs]
Note: Maps a sky addr to multiple btc addrs

Bucket: btc_txs
File: exchange/store.go

Maps: btcaddr -> [txs]
Note: Maps a btcaddr to multiple btc txns

Bucket: scan_meta
File: scanner/store.go

Maps: "last_scan_block" -> scanner.lastScanBlock[json]
Note: Saves scanner.lastScanBlock struct (as JSON) to "last_scan_block" key

Maps: "deposit_addresses" -> [btcaddrs]
Note: Saves list of btc addresss being scanned

Maps: "dv_index_list" -> [btcTx[%tx:%n]][json]
Note: Saves list of btc txid:seq (as JSON)

Bucket: deposit_value
File: scanner/store.go

Maps: btcTx[%tx:%n] -> scanner.DepositValue
Note: Maps a btc txid:seq to scanner.DepositValue struct