Move the current rendering to a debian distro file

This format allows for rendering to work in other distros
and clearly separates the API needed to do this (it also
moves the klibc parsing into its own module so that the
leftover code in net/__init__.py is smaller and only focused
on util code).

2 files changed, 401 insertions, 0 deletions

diff --git a/cloudinit/net/distros/__init__.py b/cloudinit/net/distros/__init__.py
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/cloudinit/net/distros/__init__.py
diff --git a/cloudinit/net/distros/debian.py b/cloudinit/net/distros/debian.py
new file mode 100644
index 00000000..3ab0483e
--- /dev/null
+++ b/cloudinit/net/distros/debian.py
@@ -0,0 +1,401 @@
+# vi: ts=4 expandtab
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License version 3, as
+#    published by the Free Software Foundation.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import glob
+import os
+import re
+
+from cloudinit.net import LINKS_FNAME_PREFIX
+from cloudinit.net import ParserError
+from cloudinit.net.udev import generate_udev_rule
+from cloudinit import util
+
+
+NET_CONFIG_COMMANDS = [
+    "pre-up", "up", "post-up", "down", "pre-down", "post-down",
+]
+
+NET_CONFIG_BRIDGE_OPTIONS = [
+    "bridge_ageing", "bridge_bridgeprio", "bridge_fd", "bridge_gcinit",
+    "bridge_hello", "bridge_maxage", "bridge_maxwait", "bridge_stp",
+]
+
+NET_CONFIG_OPTIONS = [
+    "address", "netmask", "broadcast", "network", "metric", "gateway",
+    "pointtopoint", "media", "mtu", "hostname", "leasehours", "leasetime",
+    "vendor", "client", "bootfile", "server", "hwaddr", "provider", "frame",
+    "netnum", "endpoint", "local", "ttl",
+]
+
+
+# TODO: switch valid_map based on mode inet/inet6
+def _iface_add_subnet(iface, subnet):
+    content = ""
+    valid_map = [
+        'address',
+        'netmask',
+        'broadcast',
+        'metric',
+        'gateway',
+        'pointopoint',
+        'mtu',
+        'scope',
+        'dns_search',
+        'dns_nameservers',
+    ]
+    for key, value in subnet.items():
+        if value and key in valid_map:
+            if type(value) == list:
+                value = " ".join(value)
+            if '_' in key:
+                key = key.replace('_', '-')
+            content += "    {} {}\n".format(key, value)
+
+    return content
+
+
+# TODO: switch to valid_map for attrs
+def _iface_add_attrs(iface):
+    content = ""
+    ignore_map = [
+        'control',
+        'index',
+        'inet',
+        'mode',
+        'name',
+        'subnets',
+        'type',
+    ]
+    if iface['type'] not in ['bond', 'bridge', 'vlan']:
+        ignore_map.append('mac_address')
+
+    for key, value in iface.items():
+        if value and key not in ignore_map:
+            if type(value) == list:
+                value = " ".join(value)
+            content += "    {} {}\n".format(key, value)
+
+    return content
+
+
+def _iface_start_entry(iface, index):
+    fullname = iface['name']
+    if index != 0:
+        fullname += ":%s" % index
+
+    control = iface['control']
+    if control == "auto":
+        cverb = "auto"
+    elif control in ("hotplug",):
+        cverb = "allow-" + control
+    else:
+        cverb = "# control-" + control
+
+    subst = iface.copy()
+    subst.update({'fullname': fullname, 'cverb': cverb})
+
+    return ("{cverb} {fullname}\n"
+            "iface {fullname} {inet} {mode}\n").format(**subst)
+
+
+def _parse_deb_config_data(ifaces, contents, src_dir, src_path):
+    """Parses the file contents, placing result into ifaces.
+
+    '_source_path' is added to every dictionary entry to define which file
+    the configration information came from.
+
+    :param ifaces: interface dictionary
+    :param contents: contents of interfaces file
+    :param src_dir: directory interfaces file was located
+    :param src_path: file path the `contents` was read
+    """
+    currif = None
+    for line in contents.splitlines():
+        line = line.strip()
+        if line.startswith('#'):
+            continue
+        split = line.split(' ')
+        option = split[0]
+        if option == "source-directory":
+            parsed_src_dir = split[1]
+            if not parsed_src_dir.startswith("/"):
+                parsed_src_dir = os.path.join(src_dir, parsed_src_dir)
+            for expanded_path in glob.glob(parsed_src_dir):
+                dir_contents = os.listdir(expanded_path)
+                dir_contents = [
+                    os.path.join(expanded_path, path)
+                    for path in dir_contents
+                    if (os.path.isfile(os.path.join(expanded_path, path)) and
+                        re.match("^[a-zA-Z0-9_-]+$", path) is not None)
+                ]
+                for entry in dir_contents:
+                    with open(entry, "r") as fp:
+                        src_data = fp.read().strip()
+                    abs_entry = os.path.abspath(entry)
+                    _parse_deb_config_data(
+                        ifaces, src_data,
+                        os.path.dirname(abs_entry), abs_entry)
+        elif option == "source":
+            new_src_path = split[1]
+            if not new_src_path.startswith("/"):
+                new_src_path = os.path.join(src_dir, new_src_path)
+            for expanded_path in glob.glob(new_src_path):
+                with open(expanded_path, "r") as fp:
+                    src_data = fp.read().strip()
+                abs_path = os.path.abspath(expanded_path)
+                _parse_deb_config_data(
+                    ifaces, src_data,
+                    os.path.dirname(abs_path), abs_path)
+        elif option == "auto":
+            for iface in split[1:]:
+                if iface not in ifaces:
+                    ifaces[iface] = {
+                        # Include the source path this interface was found in.
+                        "_source_path": src_path
+                    }
+                ifaces[iface]['auto'] = True
+        elif option == "iface":
+            iface, family, method = split[1:4]
+            if iface not in ifaces:
+                ifaces[iface] = {
+                    # Include the source path this interface was found in.
+                    "_source_path": src_path
+                }
+            elif 'family' in ifaces[iface]:
+                raise ParserError(
+                    "Interface %s can only be defined once. "
+                    "Re-defined in '%s'." % (iface, src_path))
+            ifaces[iface]['family'] = family
+            ifaces[iface]['method'] = method
+            currif = iface
+        elif option == "hwaddress":
+            ifaces[currif]['hwaddress'] = split[1]
+        elif option in NET_CONFIG_OPTIONS:
+            ifaces[currif][option] = split[1]
+        elif option in NET_CONFIG_COMMANDS:
+            if option not in ifaces[currif]:
+                ifaces[currif][option] = []
+            ifaces[currif][option].append(' '.join(split[1:]))
+        elif option.startswith('dns-'):
+            if 'dns' not in ifaces[currif]:
+                ifaces[currif]['dns'] = {}
+            if option == 'dns-search':
+                ifaces[currif]['dns']['search'] = []
+                for domain in split[1:]:
+                    ifaces[currif]['dns']['search'].append(domain)
+            elif option == 'dns-nameservers':
+                ifaces[currif]['dns']['nameservers'] = []
+                for server in split[1:]:
+                    ifaces[currif]['dns']['nameservers'].append(server)
+        elif option.startswith('bridge_'):
+            if 'bridge' not in ifaces[currif]:
+                ifaces[currif]['bridge'] = {}
+            if option in NET_CONFIG_BRIDGE_OPTIONS:
+                bridge_option = option.replace('bridge_', '', 1)
+                ifaces[currif]['bridge'][bridge_option] = split[1]
+            elif option == "bridge_ports":
+                ifaces[currif]['bridge']['ports'] = []
+                for iface in split[1:]:
+                    ifaces[currif]['bridge']['ports'].append(iface)
+            elif option == "bridge_hw" and split[1].lower() == "mac":
+                ifaces[currif]['bridge']['mac'] = split[2]
+            elif option == "bridge_pathcost":
+                if 'pathcost' not in ifaces[currif]['bridge']:
+                    ifaces[currif]['bridge']['pathcost'] = {}
+                ifaces[currif]['bridge']['pathcost'][split[1]] = split[2]
+            elif option == "bridge_portprio":
+                if 'portprio' not in ifaces[currif]['bridge']:
+                    ifaces[currif]['bridge']['portprio'] = {}
+                ifaces[currif]['bridge']['portprio'][split[1]] = split[2]
+        elif option.startswith('bond-'):
+            if 'bond' not in ifaces[currif]:
+                ifaces[currif]['bond'] = {}
+            bond_option = option.replace('bond-', '', 1)
+            ifaces[currif]['bond'][bond_option] = split[1]
+    for iface in ifaces.keys():
+        if 'auto' not in ifaces[iface]:
+            ifaces[iface]['auto'] = False
+
+
+def _parse_deb_config(path):
+    """Parses a debian network configuration file."""
+    ifaces = {}
+    with open(path, "r") as fp:
+        contents = fp.read().strip()
+    abs_path = os.path.abspath(path)
+    _parse_deb_config_data(
+        ifaces, contents,
+        os.path.dirname(abs_path), abs_path)
+    return ifaces
+
+
+class Renderer(object):
+    """Renders network information in a debian format."""
+
+    def render_persistent_net(self, network_state):
+        ''' Given state, emit udev rules to map
+            mac to ifname
+        '''
+        content = ""
+        interfaces = network_state.get('interfaces')
+        for iface in interfaces.values():
+            # for physical interfaces write out a persist net udev rule
+            if iface['type'] == 'physical' and \
+               'name' in iface and iface.get('mac_address'):
+                content += generate_udev_rule(iface['name'],
+                                              iface['mac_address'])
+
+        return content
+
+    def render_routes(self, route, indent=""):
+        """ When rendering routes for an iface, in some cases applying a route
+        may result in the route command returning non-zero which produces
+        some confusing output for users manually using ifup/ifdown[1].  To
+        that end, we will optionally include an '|| true' postfix to each
+        route line allowing users to work with ifup/ifdown without using
+        --force option.
+
+        We may at somepoint not want to emit this additional postfix, and
+        add a 'strict' flag to this function.  When called with strict=True,
+        then we will not append the postfix.
+
+        1. http://askubuntu.com/questions/168033/
+                 how-to-set-static-routes-in-ubuntu-server
+        """
+        content = ""
+        up = indent + "post-up route add"
+        down = indent + "pre-down route del"
+        eol = " || true\n"
+        mapping = {
+            'network': '-net',
+            'netmask': 'netmask',
+            'gateway': 'gw',
+            'metric': 'metric',
+        }
+        if route['network'] == '0.0.0.0' and route['netmask'] == '0.0.0.0':
+            default_gw = " default gw %s" % route['gateway']
+            content += up + default_gw + eol
+            content += down + default_gw + eol
+        elif route['network'] == '::' and route['netmask'] == 0:
+            # ipv6!
+            default_gw = " -A inet6 default gw %s" % route['gateway']
+            content += up + default_gw + eol
+            content += down + default_gw + eol
+        else:
+            route_line = ""
+            for k in ['network', 'netmask', 'gateway', 'metric']:
+                if k in route:
+                    route_line += " %s %s" % (mapping[k], route[k])
+            content += up + route_line + eol
+            content += down + route_line + eol
+
+        return content
+
+    def render_interfaces(self, network_state):
+        ''' Given state, emit etc/network/interfaces content '''
+
+        content = ""
+        interfaces = network_state.get('interfaces')
+        ''' Apply a sort order to ensure that we write out
+            the physical interfaces first; this is critical for
+            bonding
+        '''
+        order = {
+            'physical': 0,
+            'bond': 1,
+            'bridge': 2,
+            'vlan': 3,
+        }
+        content += "auto lo\niface lo inet loopback\n"
+        for dnskey, value in network_state.get('dns', {}).items():
+            if len(value):
+                content += "    dns-{} {}\n".format(dnskey, " ".join(value))
+
+        for iface in sorted(interfaces.values(),
+                            key=lambda k: (order[k['type']], k['name'])):
+
+            if content[-2:] != "\n\n":
+                content += "\n"
+            subnets = iface.get('subnets', {})
+            if subnets:
+                for index, subnet in zip(range(0, len(subnets)), subnets):
+                    if content[-2:] != "\n\n":
+                        content += "\n"
+                    iface['index'] = index
+                    iface['mode'] = subnet['type']
+                    iface['control'] = subnet.get('control', 'auto')
+                    if iface['mode'].endswith('6'):
+                        iface['inet'] += '6'
+                    elif iface['mode'] == 'static' \
+                         and ":" in subnet['address']:
+                        iface['inet'] += '6'
+                    if iface['mode'].startswith('dhcp'):
+                        iface['mode'] = 'dhcp'
+
+                    content += _iface_start_entry(iface, index)
+                    content += _iface_add_subnet(iface, subnet)
+                    content += _iface_add_attrs(iface)
+            else:
+                # ifenslave docs say to auto the slave devices
+                if 'bond-master' in iface:
+                    content += "auto {name}\n".format(**iface)
+                content += "iface {name} {inet} {mode}\n".format(**iface)
+                content += _iface_add_attrs(iface)
+
+        for route in network_state.get('routes'):
+            content += self.render_route(route)
+
+        # global replacements until v2 format
+        content = content.replace('mac_address', 'hwaddress')
+        return content
+
+    def render_network_state(self,
+        target, network_state, eni="etc/network/interfaces",
+        links_prefix=LINKS_FNAME_PREFIX,
+        netrules='etc/udev/rules.d/70-persistent-net.rules'):
+
+        fpeni = os.path.sep.join((target, eni,))
+        util.ensure_dir(os.path.dirname(fpeni))
+        with open(fpeni, 'w+') as f:
+            f.write(self.render_interfaces(network_state))
+
+        if netrules:
+            netrules = os.path.sep.join((target, netrules,))
+            util.ensure_dir(os.path.dirname(netrules))
+            with open(netrules, 'w+') as f:
+                f.write(self.render_persistent_net(network_state))
+
+        if links_prefix:
+            self.render_systemd_links(target, network_state, links_prefix)
+
+    def render_systemd_links(self, target, network_state,
+                             links_prefix=LINKS_FNAME_PREFIX):
+        fp_prefix = os.path.sep.join((target, links_prefix))
+        for f in glob.glob(fp_prefix + "*"):
+            os.unlink(f)
+
+        interfaces = network_state.get('interfaces')
+        for iface in interfaces.values():
+            if (iface['type'] == 'physical' and 'name' in iface and
+                    iface.get('mac_address')):
+                fname = fp_prefix + iface['name'] + ".link"
+                with open(fname, "w") as fp:
+                    fp.write("\n".join([
+                        "[Match]",
+                        "MACAddress=" + iface['mac_address'],
+                        "",
+                        "[Link]",
+                        "Name=" + iface['name'],
+                        ""
+                    ]))