[OpenWrt] Avoid adding dns and dns_search if proto is none

Avoid adding "dns" and "dns_search" config options for interfaces
that have "proto" set to "none".

netjsonconfig/backends/openwrt/renderers.py

@@ -184,8 +184,8 @@ def __get_dns_servers(self, uci, address):
        # allow override
        if 'dns' in uci:
            return uci['dns']
        # ignore if using DHCP
        if address['proto'] == 'dhcp':
        # ignore if using DHCP or if "proto" is none
        if address['proto'] in ['dhcp', 'none']:
            return None
        # general setting
        dns = self.config.get('dns_servers', None)
@@ -196,6 +196,9 @@ def __get_dns_search(self, uci, address):
        # allow override
        if 'dns_search' in uci:
            return uci['dns_search']
        # ignore if "proto" is none
        if address['proto'] == 'none':
            return None
        # general setting
        dns_search = self.config.get('dns_search', None)
        if dns_search:

tests/openwrt/test_network.py

@@ -585,6 +585,25 @@ def test_dns_dhcpv6_ignored(self):
""")
        self.assertEqual(o.render(), expected)

    def test_dhcp_ignored_proto_none(self):
        o = OpenWrt({
            "interfaces": [
                {
                    "name": "eth0",
                    "type": "ethernet",
                }
            ],
            "dns_servers": ["10.11.12.13", "8.8.8.8"],
            "dns_search": ["netjson.org", "openwisp.org"],
        })
        expected = self._tabs("""package network

config interface 'eth0'
    option ifname 'eth0'
    option proto 'none'
""")
        self.assertEqual(o.render(), expected)

    def test_rules(self):
        o = OpenWrt({
            "ip_rules": [