use dns resolver to get account key

examples/dump.py

@@ -10,9 +10,10 @@
 from loguru import logger
 
 sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
-from pythclient.pythclient import PythClient, V2_PROGRAM_KEY, V2_FIRST_MAPPING_ACCOUNT_KEY  # noqa
+from pythclient.pythclient import PythClient  # noqa
 from pythclient.ratelimit import RateLimit  # noqa
 from pythclient.pythaccounts import PythPriceAccount  # noqa
+from pythclient.utils import get_key # noqa
 
 logger.enable("pythclient")
 
@@ -32,9 +33,11 @@ def set_to_exit(sig: Any, frame: Any):
 async def main():
     global to_exit
     use_program = len(sys.argv) >= 2 and sys.argv[1] == "program"
+    v2_first_mapping_account_key = get_key("devnet", "mapping")
+    v2_program_key = get_key("devnet", "program")
     async with PythClient(
-        first_mapping_account_key=V2_FIRST_MAPPING_ACCOUNT_KEY,
-        program_key=V2_PROGRAM_KEY if use_program else None,
+        first_mapping_account_key=v2_first_mapping_account_key,
+        program_key=v2_program_key if use_program else None,
     ) as c:
         await c.refresh_all_prices()
         products = await c.get_products()
@@ -57,7 +60,7 @@ async def main():
         await ws.connect()
         if use_program:
             print("Subscribing to program account")
-            await ws.program_subscribe(V2_PROGRAM_KEY, await c.get_all_accounts())
+            await ws.program_subscribe(v2_program_key, await c.get_all_accounts())
         else:
             print("Subscribing to all prices")
             for account in all_prices:
@@ -88,7 +91,7 @@ async def main():
 
         print("Unsubscribing...")
         if use_program:
-            await ws.program_unsubscribe(V2_PROGRAM_KEY)
+            await ws.program_unsubscribe(v2_program_key)
         else:
             for account in all_prices:
                 await ws.unsubscribe(account)

pythclient/pythclient.py

@@ -14,17 +14,13 @@
 from .pythaccounts import PythAccount, PythMappingAccount, PythProductAccount, PythPriceAccount
 from . import exceptions, config, ratelimit
 
-V1_FIRST_MAPPING_ACCOUNT_KEY = "ArppEFcsybCLE8CRtQJLQ9tLv2peGmQoKWFuiUWm4KBP"
-V2_FIRST_MAPPING_ACCOUNT_KEY = "BmA9Z6FjioHJPpjT39QazZyhDRUdZy2ezwx4GiDdE2u2"
-V2_PROGRAM_KEY = "gSbePebfvPy7tRqimPoVecS2UsBvYv46ynrzWocc92s"
-
 
 class PythClient:
     def __init__(self, *,
                  solana_client: Optional[SolanaClient] = None,
                  solana_endpoint: str = SOLANA_DEVNET_HTTP_ENDPOINT,
                  solana_ws_endpoint: str = SOLANA_DEVNET_WS_ENDPOINT,
-                 first_mapping_account_key: str = V1_FIRST_MAPPING_ACCOUNT_KEY,
+                 first_mapping_account_key: str,
                  program_key: Optional[str] = None,
                  aiohttp_client_session: Optional[aiohttp.ClientSession] = None) -> None:
         self._first_mapping_account_key = SolanaPublicKey(first_mapping_account_key)

pythclient/utils.py

@@ -0,0 +1,35 @@
+import ast
+import dns.resolver
+from loguru import logger
+from typing import Optional
+
+DEFAULT_VERSION = "v2"
+
+
+# Retrieving keys via DNS TXT records should not be considered secure and is provided as a convenience only.
+# Accounts should be stored locally and verified before being used for production.
+def get_key(network: str, type: str, version: str = DEFAULT_VERSION) -> Optional[str]:
+    """
+    Get the program or mapping keys from dns TXT records.
+
+    Example dns records:
+
+        devnet-program-v2.pyth.network
+        mainnet-program-v2.pyth.network
+        testnet-mapping-v2.pyth.network
+    """
+    url = f"{network}-{type}-{version}.pyth.network"
+    try:
+        answer = dns.resolver.resolve(url, "TXT")
+    except dns.resolver.NXDOMAIN:
+        logger.error("TXT record for {} not found", url)
+        return ""
+    if len(answer) != 1:
+        logger.error("Invalid number of records returned for {}!", url)
+        return ""
+    # Example of the raw_key:
+    #     "program=FsJ3A3u2vn5cTVofAjvy6y5kwABJAqYWpe4975bi2epH"
+    raw_key = ast.literal_eval(list(answer)[0].to_text())
+    # program=FsJ3A3u2vn5cTVofAjvy6y5kwABJAqYWpe4975bi2epH"
+    _, key = raw_key.split("=", 1)
+    return key

tests/test_pyth_client.py

@@ -6,7 +6,7 @@
     _ACCOUNT_HEADER_BYTES, _VERSION_2, PythMappingAccount, PythPriceType, PythProductAccount, PythPriceAccount
 )
 
-from pythclient.pythclient import PythClient, V2_FIRST_MAPPING_ACCOUNT_KEY, V2_PROGRAM_KEY, WatchSession
+from pythclient.pythclient import PythClient, WatchSession
 from pythclient.solana import (
     SolanaClient,
     SolanaCommitment,
@@ -16,14 +16,17 @@
 
 from pytest_mock import MockerFixture
 
-from mock import AsyncMock
+from mock import AsyncMock, Mock
 
 
 # Using constants instead of fixtures because:
 # 1) these values are not expected to be mutated
 # 2) these values are used in get_account_info_resp() and get_program_accounts_resp()
 #    and so if they are passed in as fixtures, the functions will complain for the args
 #    while mocking the respective functions
+V2_FIRST_MAPPING_ACCOUNT_KEY = 'BmA9Z6FjioHJPpjT39QazZyhDRUdZy2ezwx4GiDdE2u2'
+V2_PROGRAM_KEY = 'gSbePebfvPy7tRqimPoVecS2UsBvYv46ynrzWocc92s'
+
 BCH_PRODUCT_ACCOUNT_KEY = '89GseEmvNkzAMMEXcW9oTYzqRPXTsJ3BmNerXmgA1osV'
 BCH_PRICE_ACCOUNT_KEY = '4EQrNZYk5KR1RnjyzbaaRbHsv8VqZWzSUtvx58wLsZbj'