Initial commit of AthonetTools

services/net_info.py

@@ -0,0 +1,43 @@
+# services/net_info.py
+import subprocess
+import json
+
+def _run(cmd: list[str]) -> str:
+    return subprocess.check_output(cmd, text=True).strip()
+
+def _first_ipv4_cidr_from_ip_json(ip_json: dict) -> str | None:
+    # Find first IPv4 on the interface
+    for addr in ip_json.get("addr_info", []):
+        if addr.get("family") == "inet" and addr.get("local") and addr.get("prefixlen") is not None:
+            return f'{addr["local"]}/{addr["prefixlen"]}'
+    return None
+
+def get_iface_cidr(iface: str) -> str | None:
+    # ip -j addr show dev eth0
+    raw = _run(["ip", "-j", "addr", "show", "dev", iface])
+    data = json.loads(raw)
+    if not data:
+        return None
+    return _first_ipv4_cidr_from_ip_json(data[0])
+
+def get_default_gw_for_iface(iface: str) -> str | None:
+    lines = _run(["ip", "route", "show", "default", "dev", iface]).splitlines()
+    for line in lines:
+        parts = line.split()
+        if parts and parts[0] == "default":
+            try:
+                idx = parts.index("via")
+                return parts[idx + 1]
+            except ValueError:
+                continue
+            except IndexError:
+                continue
+    return None
+
+def get_eth0_dhcp_snapshot() -> dict:
+    iface = "eth0"
+    cidr = get_iface_cidr(iface) or ""
+    gw   = get_default_gw_for_iface(iface) or ""
+    if not cidr or not gw:
+        raise RuntimeError("Could not determine eth0 CIDR and/or default gateway")
+    return {"iface": iface, "cidr": cidr, "gw": gw}