ci: cram: add test for tr181-dnssd

There are no tests for checking the DNS Service Discovery functionality.
In order to properly test tr181-dnssd we need to extract the services
from the responses.

`nmap -sU --script=dns-service-discovery -p5353 192.168.1.1` is supposed
to that, but advertised services don't show up in the command output.
We can still see them in the packet capture:
14:40:31.631478 IP 192.168.1.2.53064 > 192.168.1.1.5353: 0 PTR (QM)? _services._dns-sd._udp.local. (46)
14:40:31.634862 IP 192.168.1.1.5353 > 224.0.0.251.5353: 0*- [0q] 1/0/0 A 192.168.1.1 (44)
14:40:31.634862 IP 192.168.1.1.5353 > 224.0.0.251.5353: 0*- [0q] 1/0/0 PTR _mqtt._tcp.local. (70)
14:40:31.634862 IP 192.168.1.1.5353 > 224.0.0.251.5353: 0*- [0q] 1/0/0 PTR prplOS.lan._mqtt._tcp.local. (69)
14:40:31.634862 IP 192.168.1.1.5353 > 224.0.0.251.5353: 0*- [0q] 2/0/0 SRV prplOS.lan.local.:0 1648 29296, TXT "From=sah" (123)

Until we can find a way to properly check the advertised services, let's
at least make sure that the basic functionality is there.

For this purpose:
- Check DM entry.
- Check firewall rules
- Check if service responds

Signed-off-by: Yüce Kürüm <yuce.kurum@mind.be>
Signed-off-by: Yüce Kürüm <yuce.kurum_ext@softathome.com>

.gitlab/tests/cram/generic/acceleration-plan-components/067-dnssd.t

@@ -0,0 +1,41 @@
+Create R alias:
+
+  $ alias R="${CRAM_REMOTE_COMMAND:-}"
+
+Check the root datamodel settings:
+
+  $ R "ba-cli --json DNSSD.? | sed -n '2p'" | jq --sort-keys '.[0]'
+  {
+    "DNSSD.": {
+      "AdvertiseNumberOfEntries": 1,
+      "AdvertisedInterfaces": "Device.IP.Interface.3.",
+      "Enable": 1,
+      "ServiceNumberOfEntries": 0,
+      "Status": "Enabled"
+    },
+    "DNSSD.Advertise.1.": {
+      "Alias": "usp-agt-mqtt",
+      "ApplicationProtocol": "mqtt",
+      "Enable": 1,
+      "InstanceName": "usp-agt-mqtt",
+      "Port": 0,
+      "Status": "Enabled",
+      "TextRecordNumberOfEntries": 1,
+      "TransportProtocol": "TCP"
+    },
+    "DNSSD.Advertise.1.TextRecord.1.": {
+      "Key": "From",
+      "Value": "sah"
+    }
+  }
+
+Check that firewall is configured properly:
+
+  $ R "iptables -nL | grep 5353"
+  ACCEPT     udp  --  0.0.0.0/0            0.0.0.0/0            udp spt:5353
+  ACCEPT     udp  --  0.0.0.0/0            0.0.0.0/0            udp dpt:5353
+
+Check that DNS-Based Service Discovery service is responding:
+
+  $ sudo nmap -Pn  -p5353 -sU 192.168.1.1 2>&1 | grep zeroconf
+  5353/udp open|filtered zeroconf