Merge bitcoin/bitcoin#29433: contrib: rpcauth.py - Add new option (-json) to output text in json format

9adf949 contrib: rpcauth.py - Add new option (-j/--json) to output text in json format (bstin)

Pull request description:

  This is a simple change to rpcauth.py utility in order to output as json instead raw text.

  This is beneficial because integrating json output is simpler with multiple different forms of automation and tooling

ACKs for top commit:
  maflcko:
    ACK 9adf949
  achow101:
    ACK 9adf949
  willcl-ark:
    tACK 9adf949
  tdb3:
    ACK for 9adf949

Tree-SHA512: 2cdc3b2071fbe4fb32a84ce42ee8ad216cff96ed82aaef58daeb3991953ac137ae42d6898a7fdb6cbd1800e1f61ff8d292f0b150eaebdd2a3fd9d37ed7450787

Author: achow101

share/rpcauth/README.md

@@ -15,4 +15,5 @@ positional arguments:
 
 optional arguments:
   -h, --help  show this help message and exit
+  -j, --json   output data in json format
   ```

share/rpcauth/rpcauth.py

@@ -7,6 +7,7 @@
 from getpass import getpass
 from secrets import token_hex, token_urlsafe
 import hmac
+import json
 
 def generate_salt(size):
     """Create size byte hex salt"""
@@ -24,6 +25,7 @@ def main():
     parser = ArgumentParser(description='Create login credentials for a JSON-RPC user')
     parser.add_argument('username', help='the username for authentication')
     parser.add_argument('password', help='leave empty to generate a random password or specify "-" to prompt for password', nargs='?')
+    parser.add_argument("-j", "--json", help="output to json instead of plain-text", action='store_true')
     args = parser.parse_args()
 
     if not args.password:
@@ -35,9 +37,13 @@ def main():
     salt = generate_salt(16)
     password_hmac = password_to_hmac(salt, args.password)
 
-    print('String to be appended to bitcoin.conf:')
-    print(f'rpcauth={args.username}:{salt}${password_hmac}')
-    print(f'Your password:\n{args.password}')
+    if args.json:
+        odict={'username':args.username, 'password':args.password, 'rpcauth':f'{args.username}:{salt}${password_hmac}'}
+        print(json.dumps(odict))
+    else:
+        print('String to be appended to bitcoin.conf:')
+        print(f'rpcauth={args.username}:{salt}${password_hmac}')
+        print(f'Your password:\n{args.password}')
 
 if __name__ == '__main__':
     main()