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 +1,40 @@
+#!/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
+
+for addr in sys.argv[1:]:
+    snode_pubkeys = set()
+    jreq = {
+        "jsonrpc": "2.0",
+        "id": "0",
+        "method": "get_service_nodes",
+        "params": {"service_node_pubkeys": []},
+    }
+
+    # collect all snodes for this oper
+    resp = requests.post("https://public.loki.foundation/json_rpc", json=jreq)
+    for snode in resp.json().get("result").get("service_node_states", []):
+        if snode.get("operator_address") == addr:
+            snodes.add(snode.get("pubkey_ed25519"))
+
+    # print the config snippet to stdout
+    print(f"# pin edges to use oper {addr}")
+    print("[network]")
+    for line in snodes:
+        # convert base16 (hex) to zbase32 and add .snode suffix
+        print(
+            "strict-connect={}.snode".format(
+                oxenc.to_base32z(binascii.unhexlify(line.strip()))
+            )
+        )