Refactor a large part of the networking code.

Splits off distro specific code into specific files so that
other kinds of networking configuration can be written by the
various distro(s) that cloud-init supports.

It also isolates some of the cloudinit.net code so that it can
be more easily used on its own (and incorporated into other
projects such as curtin).

During this process it adds tests so that the net process can
be tested (to some level) so that the format conversion processes
can be tested going forward.

1 files changed, 457 insertions, 0 deletions

diff --git a/cloudinit/net/eni.py b/cloudinit/net/eni.py
new file mode 100644
index 00000000..a695f5ed
--- /dev/null
+++ b/cloudinit/net/eni.py
@@ -0,0 +1,457 @@
+# 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 . import LINKS_FNAME_PREFIX
+from . import ParserError
+
+from .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":
+            if split[1] == "ether":
+                val = split[2]
+            else:
+                val = split[1]
+            ifaces[currif]['hwaddress'] = val
+        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
+
+
+def convert_eni_data(eni_data):
+    # return a network config representation of what is in eni_data
+    ifaces = {}
+    _parse_deb_config_data(ifaces, eni_data, src_dir=None, src_path=None)
+    return _ifaces_to_net_config_data(ifaces)
+
+
+def _ifaces_to_net_config_data(ifaces):
+    """Return network config that represents the ifaces data provided.
+    ifaces = parse_deb_config("/etc/network/interfaces")
+    config = ifaces_to_net_config_data(ifaces)
+    state = parse_net_config_data(config)."""
+    devs = {}
+    for name, data in ifaces.items():
+        # devname is 'eth0' for name='eth0:1'
+        devname = name.partition(":")[0]
+        if devname == "lo":
+            # currently provding 'lo' in network config results in duplicate
+            # entries. in rendered interfaces file. so skip it.
+            continue
+        if devname not in devs:
+            devs[devname] = {'type': 'physical', 'name': devname,
+                             'subnets': []}
+            # this isnt strictly correct, but some might specify
+            # hwaddress on a nic for matching / declaring name.
+            if 'hwaddress' in data:
+                devs[devname]['mac_address'] = data['hwaddress']
+        subnet = {'_orig_eni_name': name, 'type': data['method']}
+        if data.get('auto'):
+            subnet['control'] = 'auto'
+        else:
+            subnet['control'] = 'manual'
+
+        if data.get('method') == 'static':
+            subnet['address'] = data['address']
+
+        for copy_key in ('netmask', 'gateway', 'broadcast'):
+            if copy_key in data:
+                subnet[copy_key] = data[copy_key]
+
+        if 'dns' in data:
+            for n in ('nameservers', 'search'):
+                if n in data['dns'] and data['dns'][n]:
+                    subnet['dns_' + n] = data['dns'][n]
+        devs[devname]['subnets'].append(subnet)
+
+    return {'version': 1,
+            'config': [devs[d] for d in sorted(devs)]}
+
+
+class Renderer(object):
+    """Renders network information in a /etc/network/interfaces 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_route(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)
+                    for route in subnet.get('routes', []):
+                        content += self._render_route(route, indent="    ")
+            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',
+            writer=None):
+
+        fpeni = os.path.sep.join((target, eni,))
+        util.ensure_dir(os.path.dirname(fpeni))
+        util.write_file(fpeni, self._render_interfaces(network_state))
+
+        if netrules:
+            netrules = os.path.sep.join((target, netrules,))
+            util.ensure_dir(os.path.dirname(netrules))
+            util.write_file(netrules,
+                            self._render_persistent_net(network_state))
+
+        if links_prefix:
+            self._render_systemd_links(target, network_state,
+                                       links_prefix=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"
+                content = "\n".join([
+                    "[Match]",
+                    "MACAddress=" + iface['mac_address'],
+                    "",
+                    "[Link]",
+                    "Name=" + iface['name'],
+                    ""
+                ])
+                util.write_file(fname, content)