Merge pull request #134 from Permissionless-Software-Foundation/ct-unstable

feat(send transaction): Allowing specific node for broadcasting txs

src/routes/v4/full-node/rawtransactions.js

@@ -140,7 +140,7 @@ class RawTransactions {
       const options = _this.routeUtils.getAxiosOptions()
 
       // Loop through each height and creates an array of requests to call in parallel
-      const promises = hexes.map(async hex => {
+      const promises = hexes.map(async (hex) => {
         options.data.id = 'decoderawtransaction'
         options.data.method = 'decoderawtransaction'
         options.data.params = [hex]
@@ -152,7 +152,7 @@ class RawTransactions {
       const axiosResult = await _this.axios.all(promises)
 
       // Retrieve the data part of the result.
-      const result = axiosResult.map(x => x.data.result)
+      const result = axiosResult.map((x) => x.data.result)
 
       res.status(200)
       return res.json(result)
@@ -254,7 +254,7 @@ class RawTransactions {
       const options = _this.routeUtils.getAxiosOptions()
 
       // Loop through each hex and create an array of promises
-      const promises = hexes.map(async hex => {
+      const promises = hexes.map(async (hex) => {
         options.data.id = 'decodescript'
         options.data.method = 'decodescript'
         options.data.params = [hex]
@@ -267,7 +267,7 @@ class RawTransactions {
       const resolved = await Promise.all(promises)
 
       // Retrieve the data from each resolved promise.
-      const result = resolved.map(x => x.data.result)
+      const result = resolved.map((x) => x.data.result)
 
       res.status(200)
       return res.json(result)
@@ -348,7 +348,7 @@ class RawTransactions {
       }
 
       // Loop through each txid and create an array of promises
-      const promises = txids.map(async txid =>
+      const promises = txids.map(async (txid) =>
         _this.getRawTransactionsFromNode(txid, verbose)
       )
 
@@ -436,7 +436,8 @@ class RawTransactions {
         return res.json({ error: 'hex must be an array' })
       }
 
-      const options = _this.routeUtils.getAxiosOptions()
+      let options = _this.routeUtils.getAxiosOptions()
+      options = _this.sendTxOptions(options)
 
       // Enforce array size rate limits
       if (!_this.routeUtils.validateArraySize(req, hexes)) {
@@ -536,7 +537,8 @@ class RawTransactions {
         })
       }
 
-      const options = _this.routeUtils.getAxiosOptions()
+      let options = _this.routeUtils.getAxiosOptions()
+      options = _this.sendTxOptions(options)
 
       // RPC call
       options.data.id = 'sendrawtransaction'
@@ -557,6 +559,28 @@ class RawTransactions {
       return _this.errorHandler(err, res)
     }
   }
+
+  // This method modifies the default axios options. It attempts to inject
+  // a specific full node to use when broadcasting transactions. This is useful
+  // because it leverages the built-in protections that a full node has against
+  // accidental double spends. It mitigates a corner-case when rapidly spending
+  // TXs on load balanced nodes. By piping all TX sends through a single node,
+  // accidental double spends can be reduced.
+  sendTxOptions (options) {
+    try {
+      if (process.env.RPC_SENDURL) {
+        console.log(`original options: ${JSON.stringify(options, null, 2)}`)
+        options.baseURL = process.env.RPC_SENDURL
+
+        console.log(`modified options: ${JSON.stringify(options, null, 2)}`)
+      }
+
+      return options
+    } catch (err) {
+      wlogger.error('Error in rawtransactions.js/sendTxOptions()')
+      throw err
+    }
+  }
 }
 
 module.exports = RawTransactions

start-dev-example.sh

@@ -15,6 +15,11 @@ export RPC_BASEURL=http://$RPC_IP/
 export RPC_USERNAME=bitcoin
 export RPC_PASSWORD=password
 
+# (optional) If load-balancing multiple full nodes, it's best to pick a single
+# one for broadcasting transactions to the network. Prevents accidental
+# double spends.
+#export RPC_SENDURL=http://$RPC_IP/
+
 # SLPDB
 export SLPDB_PASS_GP=somelongpassword
 export SLPDB_URL=http://<SLPDB IP>:12300/

test/v4/raw-transactions.js

@@ -1047,10 +1047,12 @@ describe('#Raw-Transactions', () => {
       // Save the existing RPC URL.
       const savedUrl = process.env.BITCOINCOM_BASEURL
       const savedUrl2 = process.env.RPC_BASEURL
+      const savedUrl3 = process.env.RPC_SENDURL
 
       // Manipulate the URL to cause a 500 network error.
       process.env.BITCOINCOM_BASEURL = 'http://fakeurl/api/'
       process.env.RPC_BASEURL = 'http://fakeurl/api/'
+      process.env.RPC_SENDURL = 'http://fakeurl/api/'
 
       req.params.hex =
         '020000000136697692fed77bc4f5b6885295d0c56d1d0280fb578f445ce42be4eb6db381f2010000006a4730440220473adba0e7da14f0abf4817bbd591741ecb8da6544b998f10341f6704f5f05280220405221c626cb7edcf333367ebd469aff3f5a2169e37ee58eebb811ffc2fbc9e0412102202ff86325c5d903171fa5a2895c4efb3765105115460dc96f113048ddb69b47feffffff027a621b00000000001976a914e0a8ffc3b91e35f46618d6db90f66397989abf0588ac38041300000000001976a914a741f282af390bc7ea8c4375a3a56401d668564288ac2c330900'
@@ -1060,6 +1062,7 @@ describe('#Raw-Transactions', () => {
       // Restore the saved URL.
       process.env.BITCOINCOM_BASEURL = savedUrl
       process.env.RPC_BASEURL = savedUrl2
+      process.env.RPC_SENDURL = savedUrl3
 
       assert.isAbove(
         res.statusCode,