Go

18_1_Accessing_Bitcoind_with_Go.md

@@ -0,0 +1,337 @@
+# 18.1: Accessing Bitcoind with NodeJS
+
+## Set up Go
+
+First, install curl if you haven't already:
+
+```
+$ sudo apt install curl
+```
+
+Then, look at the [Go downloads page](https://golang.org/dl/) and get the link for the latest download:
+
+```
+$ curl -O https://dl.google.com/go/go1.14.4.linux-amd64.tar.gz
+```
+
+Once it finishes downloading, compare the hash of the download to the hash on the [Go downloads page](https://golang.org/dl/):
+
+```
+$ sha256sum go1.14.4.linux-amd64.tar.gz
+aed845e4185a0b2a3c3d5e1d0a35491702c55889192bb9c30e67a3de6849c067  /home/user1/go1.14.4.linux-amd64.tar.gz
+```
+
+The hashes should match. Now we can extract the tarball and install Go on our system:
+
+```
+$ tar xvf go1.12.5.linux-amd64.tar.gz
+$ sudo chown -R root:root ./go
+$ sudo mv go /usr/local
+```
+
+Now we need to create a Go path to specify our environment. Open the ```~/.profile``` file with an editor of your choice and add the following to the end of it:
+
+```
+export GOPATH=$HOME/work
+export PATH=$PATH:/usr/local/go/bin:$GOPATH/bin
+```
+
+Then, refresh your profile:
+
+```
+$ source ~/.profile
+```
+
+Lastly, create the directory for your Go workspace:
+
+```
+$ mkdir $HOME/work
+```
+
+## Setup btcd rpcclient
+
+We will be using the rpcclient that comes with btcd, a Bitcoin implementation written in Go. We can use ```go get``` to download it:
+
+```
+$ go get github.com/btcsuite/btcd/rpcclient
+```
+
+To test that it works, navigate to the directory with the Bitcoin core examples:
+
+```
+$ cd $GOPATH/src/github.com/btcsuite/btcd/rpcclient/examples/bitcoincorehttp
+```
+
+Modify the ```main.go``` file and enter the details associated with your Bitcoin core setup:
+
+```
+		Host:         "localhost:18332",
+		User:         "bitcoinrpc",
+		Pass:         "d8340efbcd34e312044c8431c59c792c",
+```
+
+Now run:
+
+```
+$ go run main.go
+```
+
+You should see the block count printed:
+
+```
+2020/06/24 20:41:01 Block count: 1773552
+```
+
+### Print the latest block
+
+Leave the btcd directory and create a new Go project:
+
+```
+$ mkdir -p ~/work/src/myproject/bitcoin
+$ cd ~/work/src/myproject/bitcoin
+```
+
+In this directory, create a file called ```main.go``` and enter the following in it:
+
+```
+package main
+
+import (
+	"log"
+	"fmt"
+	"github.com/btcsuite/btcd/rpcclient"
+)
+
+func main() {
+	connCfg := &rpcclient.ConnConfig{
+		Host:         "localhost:18332",
+		User:         "bitcoinrpc",
+		Pass:         "431451790e3eee1913115b9dd2fbf0ac",
+		HTTPPostMode: true,
+		DisableTLS:   true,
+	}
+	client, err := rpcclient.New(connCfg, nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer client.Shutdown()
+
+	blockCount, err := client.GetBlockCount()
+	if err != nil {
+		log.Fatal(err)
+	}
+	blockHash, err := client.GetBlockHash(blockCount)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Printf("%d\n", blockCount)
+	fmt.Printf("%s\n", blockHash.String())
+}
+```
+
+Make sure to change your username and password to those from your ```~/.bitcoin/bitcoin.conf``` file. When you run this:
+
+```
+$ go run main.go
+1773561
+00000000000000346bab4126f418a5820692c9a7de7ef79717bebfccebacad61
+```
+
+The latest block number along with its hash should be printed out.
+
+### Getting your wallet balance
+
+Since the btcd rpcclient is quite limited, we can't make a use the ```getwalletinfo``` functino, however we can get the balance of our wallet:
+
+```
+package main
+
+import (
+	"log"
+	"fmt"
+	"github.com/btcsuite/btcd/rpcclient"
+)
+
+func main() {
+	connCfg := &rpcclient.ConnConfig{
+		Host:         "localhost:18332",
+		User:         "bitcoinrpc",
+		Pass:         "431451790e3eee1913115b9dd2fbf0ac",
+		HTTPPostMode: true,
+		DisableTLS:   true,
+	}
+	client, err := rpcclient.New(connCfg, nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer client.Shutdown()
+
+	wallet, err := client.GetBalance("*")
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Println(wallet)
+}
+```
+
+You should get an output similar to this:
+
+```
+0.000689 BTC
+```
+
+### Get amount received by an address
+
+We can retrieve the amount of Bitcoin received by a specific address:
+
+```
+package main
+
+import (
+	"log"
+	"fmt"
+	"github.com/btcsuite/btcd/rpcclient"
+	"github.com/btcsuite/btcutil"
+	"github.com/btcsuite/btcd/chaincfg"
+)
+
+func main() {
+	connCfg := &rpcclient.ConnConfig{
+		Host:         "localhost:18332",
+		User:         "bitcoinrpc",
+		Pass:         "431451790e3eee1913115b9dd2fbf0ac",
+		HTTPPostMode: true,
+		DisableTLS:   true,
+	}
+	client, err := rpcclient.New(connCfg, nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer client.Shutdown()
+
+	defaultNet := &chaincfg.TestNet3Params
+	addr, err := btcutil.DecodeAddress("mpGpCMX6SuUimDZKiVViuhd7EGyVxkNnha", defaultNet)
+	if err != nil {
+		log.Fatal(err)
+	}
+	wallet, err := client.GetReceivedByAddress(addr)
+
+	fmt.Println(wallet)
+}
+```
+
+The defaultNet variable is used to specify whether our Bitcoin node is on testnet or on mainnet.
+
+### Sending Bitcoin to an address
+
+```
+package main
+
+import (
+	"log"
+	"fmt"
+	"github.com/btcsuite/btcd/rpcclient"
+	"github.com/btcsuite/btcutil"
+	"github.com/btcsuite/btcd/chaincfg"
+)
+
+func main() {
+	connCfg := &rpcclient.ConnConfig{
+		Host:         "localhost:18332",
+		User:         "bitcoinrpc",
+		Pass:         "431451790e3eee1913115b9dd2fbf0ac",
+		HTTPPostMode: true,
+		DisableTLS:   true,
+	}
+	client, err := rpcclient.New(connCfg, nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer client.Shutdown()
+
+	defaultNet := &chaincfg.TestNet3Params
+	addr, err := btcutil.DecodeAddress("n2eMqTT929pb1RDNuqEnxdaLau1rxy3efi", defaultNet)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	sent, err := client.SendToAddress(addr, btcutil.Amount(1e4))
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Println(sent)
+}
+```
+
+This outputs the txid of the transaction.
+
+### Lookup a transaction
+
+```
+package main
+
+import (
+	"log"
+	"fmt"
+	"github.com/btcsuite/btcd/rpcclient"
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
+)
+
+func main() {
+	connCfg := &rpcclient.ConnConfig{
+		Host:         "localhost:18332",
+		User:         "bitcoinrpc",
+		Pass:         "431451790e3eee1913115b9dd2fbf0ac",
+		HTTPPostMode: true,
+		DisableTLS:   true,
+	}
+	client, err := rpcclient.New(connCfg, nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer client.Shutdown()
+
+	chash, err := chainhash.NewHashFromStr("1661ce322c128e053b8ea8fcc22d17df680d2052983980e2281d692b9b4ab7df")
+	if err != nil {
+		log.Fatal(err)
+	}
+	transactions, err := client.GetTransaction(chash)
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Println(transactions)
+}
+```
+
+This prints out the details associated with a transaction, such as its amount and how many times it has been confirmed:
+
+```
+{
+  "amount": 0.00100000,
+  "confirmations": 4817,
+  "blockhash": "000000006628870b0a8a66abea9cf0d4e815c491f079e3fa9e658a87b5dc863a",
+  "blockindex": 117,
+  "blocktime": 1591857418,
+  "txid": "1661ce322c128e053b8ea8fcc22d17df680d2052983980e2281d692b9b4ab7df",
+  "walletconflicts": [
+  ],
+  "time": 1591857343,
+  "timereceived": 1591857343,
+  "bip125-replaceable": "no",
+  "details": [
+    {
+      "address": "mpGpCMX6SuUimDZKiVViuhd7EGyVxkNnha",
+      "category": "receive",
+      "amount": 0.00100000,
+      "label": "",
+      "vout": 0
+    }
+  ],
+  "hex": "02000000000101e9e8c3bd057d54e73baadc60c166860163b0e7aa60cab33a03e89fb44321f8d5010000001716001435c2aa3fc09ea53c3e23925c5b2e93b9119b2568feffffff02a0860100000000001976a914600c8c6a4abb0a502ea4de01681fe4fa1ca7800688ac65ec1c000000000017a91425b920efb2fde1a0277d3df11d0fd7249e17cf8587024730440220403a863d312946aae3f3ef0a57206197bc67f71536fb5f4b9ca71a7e226b6dc50220329646cf786cfef79d60de3ef54f702ab1073694022f0618731902d926918c3e012103e6feac9d7a8ad1ac6b36fb4c91c1c9f7fff1e7f63f0340e5253a0e4478b7b13f41fd1a00"
+}
+```
+
+## Summary: Accessing Bitcoind with Node
+
+Although the btcd rpcclient is quite limited, we can still perform a lot of the main rpc commands in Go. 

18_3_Accessing_Bitcoind_with_NodeJS.md

@@ -201,9 +201,9 @@ You should get an output similar to this:
 }
 ```
 
-### Get address balance
+### Get Amount Received by an Address
 
-A useful function when accepting Bitcoin is checking the balance of a specific address in your wallet. For example, if you were running an online store accepting Bitcoin, for each payment from a customer, you would generate a new address (as we did with ```getNewAddress``` function), show that address to the customer, then check the balance of the address after some time, to make sure the correct amount has been received:
+A useful function when accepting Bitcoin is checking the received Bitcoin of a specific address in your wallet. For example, if you were running an online store accepting Bitcoin, for each payment from a customer, you would generate a new address (as we did with ```getNewAddress``` function), show that address to the customer, then check the balance of the address after some time, to make sure the correct amount has been received:
 
 ```
 agent.getReceivedByAddress('mpGpCMX6SuUimDZKiVViuhd7EGyVxkNnha', function (err, addressInfo) {

README.md

@@ -104,9 +104,9 @@ _This section is currently a messy set of older writings which are being reorgan
    * 17.4: Integrating Libwally and Scripts
 * 17.0: Talking to Lightningd with C
 * 18.0: Talking to Bitcoind with Other Languages
-  * [18.1: Accessing Bitcoind with Go]
+  * [18.1: Accessing Bitcoind with Go](18_1_Accessing_Bitcoind_with_Go.md)
   * [18.2: Accessing Bitcoind with Java](18_2_Accessing_Bitcoind_with_Java.md) — Needs Rewrite + Editing
-  * [18.3: Accessing Bitcoind with Node JS](18_3_Accessing_Bitcoind_with_NodeJS.md)  — Needs Rewrite + Editing
+  * [18.3: Accessing Bitcoind with Node JS](18_3_Accessing_Bitcoind_with_NodeJS.md)
   * [18.4: Accessing Bitcoind with Python]
   * [18.5: Accessing Bitcoind with Rust]
   * [18.6: Accessing Bitcoind with Swift]