freebsd: introduce the freebsd renderer (#61)

* freebsd: introduce the freebsd renderer

Refactoring of the FreeBSD code base to provide a real network renderer
for FreeBSD.
Use the generic update_sysconfig_file() from rhel_util to handle the
access to /etc/rc.conf.
Interfaces are not automatically renamed by FreeBSD using
the following configuration in /etc/rc.conf:

```
ifconfig_fxp0_name="eth0"
```

* freesd: use regex named groups

Reduce the complexity of `get_interfaces_by_mac_on_freebsd()` with
named groups.

* freebsd: breaks up _write_network() in tree small functions

- `_write_ifconfig_entries()`
- `_write_route_entries()`
- `_write_resolve_conf()`

* extend find_fallback_nic() to support FreeBSD

this uses `route -n show default` to find the default interface

* freebsd: use dns keys from NetworkState class

The NetworkState class (settings instance) exposes the DNS configuration
in two keys:

- `dns_nameservers`
- `dns_searchdomains`

On OpenStack, these keys are set when a global DNS server is set. The
alternative is the `dns_nameservers` and `dns_search` keys from each
subdomain. We continue to read those.

* freebsd: properly target the /etc/resolv.conf file

* freebsd: ignore 'service routing restart' ret code

On FreeBSD 10, the restart of routing and dhclient is likely to fail because
- routing: it cannot remove the loopback route, but it will still set up
  the default route as expected.
- dhclient: it cannot stop the dhclient started by the netif service.
In both case, the situation is ok, and we can proceed.

* freebsd: handle case when metadata MAC local locally

Handle the case where the metadata configuration comes with a MAC that
does not exist locally.

See:
- https://github.com/canonical/cloud-init/pull/61/files/635ce14b3153934ba1041be48b7245062f21e960#r359600604
- https://github.com/canonical/cloud-init/pull/61/files/635ce14b3153934ba1041be48b7245062f21e960#r359600966

* freebsd: show up a warning if several subnet found

The FreeBSD provider currently only allow one subnet per interface.

* freebsd: honor the target parameter in _write_network

* freebsd: log when a bad route is found

* freebsd: pass _postcmds to start_services()

* freebsd: updatercconf() is depercated

Replace `updatercconf()` by `rhel_util.update_sysconfig_file()`.

* freebsd: ensure gateway is ipv4 before using it

With the legacy ENI format, an IPv6 gateway may be pushed. This instead
of the expected IPv4.

* freebsd: find_fallback_nic, support FB10

On FreeBSD <= 10, `ifconfig -l` ignores the down interfaces.

* freebsd: use util.target_path() to load resolv.conf

Ensure we access `/etc/resolv.conf`, not `etc/resolv.conf`.

* freebsd: skip subnet without netmask

Those are likely to be either invalid of in IPv6 format. IPv6 support
will be addressed later in a new patchset.

* freebsd: get_devicelist returns netif list

Ensure `get_devicelist()` returns the list of known netif on FreeBSD.

* replace rhel_util.update_sysconfig_file wrapper call, with a wrapper function

* reverse if condition to remove an indent

Co-authored-by: Igor Galić <me+github@igalic.co>

1 files changed, 66 insertions, 0 deletions

diff --git a/cloudinit/net/__init__.py b/cloudinit/net/__init__.py
index bd806378..1d5eb535 100644
--- a/cloudinit/net/__init__.py
+++ b/cloudinit/net/__init__.py
@@ -307,6 +307,9 @@ def device_devid(devname):
 
 
 def get_devicelist():
+    if util.is_FreeBSD():
+        return list(get_interfaces_by_mac().values())
+
     try:
         devs = os.listdir(get_sys_class_path())
     except OSError as e:
@@ -329,6 +332,35 @@ def is_disabled_cfg(cfg):
 
 def find_fallback_nic(blacklist_drivers=None):
     """Return the name of the 'fallback' network device."""
+    if util.is_FreeBSD():
+        return find_fallback_nic_on_freebsd(blacklist_drivers)
+    else:
+        return find_fallback_nic_on_linux(blacklist_drivers)
+
+
+def find_fallback_nic_on_freebsd(blacklist_drivers=None):
+    """Return the name of the 'fallback' network device on FreeBSD.
+
+    @param blacklist_drivers: currently ignored
+    @return default interface, or None
+
+
+    we'll use the first interface from ``ifconfig -l -u ether``
+    """
+    stdout, _stderr = util.subp(['ifconfig', '-l', '-u', 'ether'])
+    values = stdout.split()
+    if values:
+        return values[0]
+    # On FreeBSD <= 10, 'ifconfig -l' ignores the interfaces with DOWN
+    # status
+    values = list(get_interfaces_by_mac().values())
+    values.sort()
+    if values:
+        return values[0]
+
+
+def find_fallback_nic_on_linux(blacklist_drivers=None):
+    """Return the name of the 'fallback' network device on Linux."""
     if not blacklist_drivers:
         blacklist_drivers = []
 
@@ -765,6 +797,40 @@ def get_ib_interface_hwaddr(ifname, ethernet_format):
 
 
 def get_interfaces_by_mac():
+    if util.is_FreeBSD():
+        return get_interfaces_by_mac_on_freebsd()
+    else:
+        return get_interfaces_by_mac_on_linux()
+
+
+def get_interfaces_by_mac_on_freebsd():
+    (out, _) = util.subp(['ifconfig', '-a', 'ether'])
+
+    # flatten each interface block in a single line
+    def flatten(out):
+        curr_block = ''
+        for l in out.split('\n'):
+            if l.startswith('\t'):
+                curr_block += l
+            else:
+                if curr_block:
+                    yield curr_block
+                curr_block = l
+        yield curr_block
+
+    # looks for interface and mac in a list of flatten block
+    def find_mac(flat_list):
+        for block in flat_list:
+            m = re.search(
+                r"^(?P<ifname>\S*): .*ether\s(?P<mac>[\da-f:]{17}).*",
+                block)
+            if m:
+                yield (m.group('mac'), m.group('ifname'))
+    results = {mac: ifname for mac, ifname in find_mac(flatten(out))}
+    return results
+
+
+def get_interfaces_by_mac_on_linux():
     """Build a dictionary of tuples {mac: name}.
 
     Bridges and any devices that have a 'stolen' mac are excluded."""