add python script which generates an ini config snippet to pin edges

takes in multiple wallet addresses as arguments and outputs to stdout
a config snippet that manually pins all snodes from those opers.

contrib/snode-pin.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python3
+#
+# a script to generate a lokinet ini file that pins your edges to use only snodes run under the wallet addresses of a whitelist of opers.
+#
+# usage: ./snode-pin.py walletaddr1 walletaddr2 ... walletaddrN > 00-edges.ini
+#
+# then copy 00-edges.ini into /var/lib/lokinet/conf.d/
+# create that dir if it does not exist.
+#
+
+import oxenc
+import binascii
+import sys
+import requests
+
+from collections import defaultdict
+
+addrs = sys.argv[1:]
+snodes = defaultdict(set)
+jreq = {
+    "jsonrpc": "2.0",
+    "id": "0",
+    "method": "get_service_nodes",
+    "params": {"service_node_pubkeys": []},
+}
+
+# collect all snodes
+resp = requests.post("https://public.loki.foundation/json_rpc", json=jreq)
+for snode in resp.json().get("result").get("service_node_states", []):
+    addr = snode.get("operator_address", None)
+    if addr in addrs:
+        snodes[addr].add(snode.get("pubkey_ed25519"))
+
+# print the config snippet to stdout
+for oper in snodes:
+    print(f"# pin edges to use oper {oper}")
+    print("[network]")
+    for addr in snodes.get(oper):
+        # convert base16 (hex) to zbase32 and add .snode suffix
+        print(
+            "strict-connect={}.snode".format(
+                oxenc.to_base32z(binascii.unhexlify(addr.strip()))
+            )
+        )