Update blockchain_explorer.py to be configurable (#145)

- Add CLI params for listen port, mobilecoind host and port
- Removes the need for using `flusk run` but that will still work as previously configured

mobilecoind/clients/python/blockchain_explorer.py

@@ -1,23 +1,49 @@
 # Copyright (c) 2018-2020 MobileCoin Inc.
 
+import argparse
 from mob_client import mob_client
 from flask import Flask, render_template
 from sys import getsizeof
 
-mob_client = mob_client('localhost:4444', False)
+client = mob_client('localhost:4444', False)
 app = Flask(__name__)
 
+def command_args():
+    parser = argparse.ArgumentParser(description='MobileCoin Block Explorer')
+    parser.add_argument(
+        '--port',
+        type=int,
+        required=False,
+        default=5000,
+        help='Block Explorer listen port'
+    )
+    parser.add_argument(
+        '--mobilecoind_port',
+        type=int,
+        required=False,
+        default=4444,
+        help='Port of mobilecoind service to connect to'
+    )
+    parser.add_argument(
+        '--mobilecoind_host',
+        type=str,
+        required=False,
+        default='localhost',
+        help='Hostname of mobilecoind service to connect to'
+    )
+    return parser.parse_args()
+
 @app.route('/')
 def index():
-    num_blocks, num_transactions = mob_client.get_ledger_info()
+    num_blocks, num_transactions = client.get_ledger_info()
 
     blocks = []
     for i in range(num_blocks - 1, max(num_blocks - 100, -1), -1):
-        _key_image_count, txo_count = mob_client.get_block_info(i)
+        _key_image_count, txo_count = client.get_block_info(i)
         # Will get ResourceExhausted if message larger than 4194304
         if txo_count > 20000:
             continue
-        block = mob_client.get_block(i)
+        block = client.get_block(i)
         size_of_block = getsizeof(block) * .001
         block_row = (i, txo_count, size_of_block, bytes.hex(block.block.contents_hash.data))
         blocks.append(block_row)
@@ -29,7 +55,7 @@ def index():
 
 @app.route('/block/<block_num>')
 def block(block_num):
-    block = mob_client.get_block(int(block_num))
+    block = client.get_block(int(block_num))
     size_of_block = getsizeof(block)
     return render_template('block.html',
         block_num=int(block_num),
@@ -39,3 +65,8 @@ def block(block_num):
         txos=block.txos,
         key_images=block.key_images,
         size_of_block=size_of_block)
+
+if __name__ == "__main__":
+    args = command_args()
+    client = mob_client(args.mobilecoind_host + ':' + str(args.mobilecoind_port), False) 
+    app.run(host='0.0.0.0', port=str(args.port))