Initial commit of AthonetTools

services/local_net.py

@@ -0,0 +1,42 @@
+# services/local_net.py
+import subprocess
+import re
+
+def _sh(cmd):
+    out = subprocess.check_output(cmd, text=True)
+    return out
+
+def get_eth0_dhcp_snapshot():
+    """
+    Returns {'iface':'eth0','cidr':'X.X.X.X/YY','ip':'X.X.X.X','prefixlen':YY,'gw':'A.B.C.D'}
+    Raises on failure.
+    """
+    iface = "eth0"
+
+    # ip -o -4 addr show dev eth0 | awk '{print $4}'
+    addrs = _sh(["/sbin/ip", "-o", "-4", "addr", "show", "dev", iface]).strip()
+    if not addrs:
+        addrs = _sh(["ip", "-o", "-4", "addr", "show", "dev", iface]).strip()
+
+    m = re.search(r"\s(\d+\.\d+\.\d+\.\d+/\d+)\s", addrs)
+    if not m:
+        raise RuntimeError(f"No IPv4 address on {iface}")
+    cidr = m.group(1)
+    ip = cidr.split("/")[0]
+    prefixlen = int(cidr.split("/")[1])
+
+    # ip route show default dev eth0 | awk '/default/ {print $3}'
+    routes = _sh(["/sbin/ip", "route", "show", "default", "dev", iface])
+    if not routes:
+        routes = _sh(["ip", "route", "show", "default", "dev", iface])
+
+    m2 = re.search(r"default via (\d+\.\d+\.\d+\.\d+)", routes)
+    gw = m2.group(1) if m2 else ""
+
+    return {
+        "iface": iface,
+        "cidr": cidr,
+        "ip": ip,
+        "prefixlen": prefixlen,
+        "gw": gw
+    }