Add missing charmhelper

hooks/charmhelpers/contrib/network/ip.py

@@ -0,0 +1,69 @@
+import sys
+
+from charmhelpers.fetch import apt_install
+from charmhelpers.core.hookenv import (
+    ERROR, log,
+)
+
+try:
+    import netifaces
+except ImportError:
+    apt_install('python-netifaces')
+    import netifaces
+
+try:
+    import netaddr
+except ImportError:
+    apt_install('python-netaddr')
+    import netaddr
+
+
+def _validate_cidr(network):
+    try:
+        netaddr.IPNetwork(network)
+    except (netaddr.core.AddrFormatError, ValueError):
+        raise ValueError("Network (%s) is not in CIDR presentation format" %
+                         network)
+
+
+def get_address_in_network(network, fallback=None, fatal=False):
+    """
+    Get an IPv4 address within the network from the host.
+
+    :param network (str): CIDR presentation format. For example,
+        '192.168.1.0/24'.
+    :param fallback (str): If no address is found, return fallback.
+    :param fatal (boolean): If no address is found, fallback is not
+        set and fatal is True then exit(1).
+
+    """
+
+    def not_found_error_out():
+        log("No IP address found in network: %s" % network,
+            level=ERROR)
+        sys.exit(1)
+
+    if network is None:
+        if fallback is not None:
+            return fallback
+        else:
+            if fatal:
+                not_found_error_out()
+
+    _validate_cidr(network)
+    for iface in netifaces.interfaces():
+        addresses = netifaces.ifaddresses(iface)
+        if netifaces.AF_INET in addresses:
+            addr = addresses[netifaces.AF_INET][0]['addr']
+            netmask = addresses[netifaces.AF_INET][0]['netmask']
+            cidr = netaddr.IPNetwork("%s/%s" % (addr, netmask))
+            if cidr in netaddr.IPNetwork(network):
+                return str(cidr.ip)
+
+    if fallback is not None:
+        return fallback
+
+    if fatal:
+        not_found_error_out()
+
+    return None