QA: Support master-netdev and default NIC parameters

Requested in issue 337.

The parameter “bridge” was not documented and is therefore silently
replaced with “master-netdev”. A note is added to “qa-sample.json”
describing how comments work.

This is a cherry-pick of master commit
3601d488

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

qa/qa-sample.json

 {
+  "# Note:": null,
+  "# This file is stored in the JSON format and does not support": null,
+  "# comments. As a work-around, comments are keys starting with a hash": null,
+  "# sign (#).": null,
+
   "name": "xen-test",
   "rename": "xen-test-rename",
   "enabled-hypervisors": "xen-pvm",
@@ -12,6 +17,15 @@
   "os-hvp": {},
   "primary_ip_version": 4,
 
+  "# Network interface for master role": null,
+  "#master-netdev": "xen-br0",
+
+  "# Default network interface parameters": null,
+  "#default-nicparams": {
+    "mode": "bridged",
+    "link": "xen-br0",
+  },
+
   "os": "debian-etch",
   "maxmem": "1024M",
   "minmem": "512M",

qa/qa_cluster.py

@@ -104,16 +104,21 @@ def TestClusterInit(rapi_user, rapi_secret):
                     "nic-count"):
     for spec_val in ("min", "max", "std"):
       spec = qa_config.get("ispec_%s_%s" %
-                           (spec_type.replace('-', '_'), spec_val), None)
+                           (spec_type.replace("-", "_"), spec_val), None)
       if spec:
         cmd.append("--specs-%s=%s=%d" % (spec_type, spec_val, spec))
 
   if master.get("secondary", None):
     cmd.append("--secondary-ip=%s" % master["secondary"])
 
-  bridge = qa_config.get("bridge", None)
-  if bridge:
-    cmd.append("--master-netdev=%s" % bridge)
+  master_netdev = qa_config.get("master-netdev", None)
+  if master_netdev:
+    cmd.append("--master-netdev=%s" % master_netdev)
+
+  nicparams = qa_config.get("default-nicparams", None)
+  if nicparams:
+    cmd.append("--nic-parameters=%s" %
+               ",".join(utils.FormatKeyValue(nicparams)))
 
   cmd.append(qa_config.get("name"))
   AssertCommand(cmd)