Add helper files

src/settings.py

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+""" General settings """
+
+# Prefix to all the networks and containers created
+PREFIX = "testnw"
+
+# Container base installation path -- will be overlaid
+CONTAINER_BASE_ROOT = "/var/lib/machines/lxc-base-" + PREFIX
+
+# Overlayfs mount dir
+OVERLAYFS_MOUNT_DIR = "/tmp/{}-overlays/".format(PREFIX)
+
+# The ID of the whole generated network -- below 0xff
+NETWORK_ID = 132
+
+# IPv4 /16 range
+IPV4_RANGE = "10.{}".format(NETWORK_ID)
+
+# IPv6 /32 range
+IPV6_RANGE = "fd80:ba{:02x}".format(NETWORK_ID)

src/util.py

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+""" Various utils """
+
+import settings
+
+
+class NumberedClass:
+    """ A class that counts its current instance number """
+
+    next_id = 0
+
+    @classmethod
+    def get_id(cls):
+        out = cls.next_id
+        cls.next_id += 1
+        return out
+
+    def __init__(self):
+        self.id = self.get_id()
+
+
+class MACAddress:
+    """ A MAC address for a NIC or bridge """
+
+    def __init__(self, link_id, dev_id):
+        """ link_id: id of the current link
+            dev_id: id of the current NIC. If the device is a bridge, use None
+        """
+        if not dev_id:
+            dev_id = 0xFF
+
+        self.link_id = link_id
+        self.dev_id = dev_id
+
+    def __str__(self):
+        return "52:54:00:{nwid:02x}:{link_id:02x}:{dev_id:02x}".format(
+            nwid=settings.NETWORK_ID, link_id=self.link_id, dev_id=self.dev_id
+        )
+
+    def __repr__(self):
+        return str(self)
+
+
+class Addrv4:
+    """ An address in IPv4 """
+
+    def __init__(self, link_id, dev_id):
+        """ link_id: id of the current link
+            dev_id: id of the current NIC. Use None to get the base address
+        """
+        if not dev_id:
+            dev_id = 0
+
+        self.link_id = link_id
+        self.dev_id = dev_id
+        self.netmask = "255.255.255.0"
+        self.prefix = 24
+
+    def __str__(self):
+        return "{base_range}.{link_id}.{dev_id}".format(
+            base_range=settings.IPV4_RANGE, link_id=self.link_id, dev_id=self.dev_id
+        )
+
+    def __repr__(self):
+        return str(self)
+
+
+class Addrv6:
+    """ An address in IPv6 """
+
+    def __init__(self, link_id, dev_id):
+        """ link_id: id of the current link
+            dev_id: id of the current NIC. Use None to get the base address
+        """
+        if not dev_id:
+            dev_id = 0
+
+        self.link_id = link_id
+        self.dev_id = dev_id
+        self.prefix = 64
+
+    def __str__(self):
+        return "{base_range}:{link_id:04x}::{dev_id:04x}".format(
+            base_range=settings.IPV6_RANGE, link_id=self.link_id, dev_id=self.dev_id
+        )

src/xml_template.py

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+""" Reads an XML template from a file """
+
+import os
+
+
+class XMLTemplate:
+    """ Reads and instanciates a template from a file """
+
+    def __init__(self, path):
+        self.path = os.path.join(os.path.dirname(os.path.abspath(__file__)), path)
+        with open(self.path, "r") as handle:
+            self.template_str = handle.read()
+
+    def inst(self, *args, **kwargs):
+        """ instanciates the template """
+        return self.template_str.format(*args, **kwargs)