[PATCH v3 08/20] avocado/tasst: Add helper to get network interface names for a site

[David Gibson <david@gibson.dropbear.id.au>]

Start adding convenience functions for handling sites as places with
network setup with a simple helper which lists the network interface names
for a site.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 avocado/tasst/site.py | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/avocado/tasst/site.py b/avocado/tasst/site.py
index 6aa83c4..6450944 100644
--- a/avocado/tasst/site.py
+++ b/avocado/tasst/site.py
@@ -11,6 +11,7 @@
 # Author: David Gibson <david@gibson.dropbear.id.au>
 
 import contextlib
+import json
 
 import avocado
 from avocado.utils.process import CmdError
@@ -50,6 +51,11 @@ class Site(contextlib.AbstractContextManager):
             raise avocado.TestCancel("Missing commands {} on {}"
                                      .format(', '.join(missing), self.name))
 
+    def ifs(self):
+        self.require_cmds('ip')
+        info = json.loads(self.output('ip -j link show'))
+        return [i['ifname'] for i in info]
+
 
 class SiteTasst(Tasst):
     """
@@ -90,6 +96,10 @@ class SiteTasst(Tasst):
                 status = proc.wait()
                 self.assertNotEquals(status, 0)
 
+    def test_has_lo(self):
+        with self.setup_site() as site:
+            self.assertIn('lo', site.ifs())
+
 
 # Represents the host on which the tests are running, as opposed to
 # some simulated host created by the tests
-- 
@@ -11,6 +11,7 @@
 # Author: David Gibson <david@gibson.dropbear.id.au>
 
 import contextlib
+import json
 
 import avocado
 from avocado.utils.process import CmdError
@@ -50,6 +51,11 @@ class Site(contextlib.AbstractContextManager):
             raise avocado.TestCancel("Missing commands {} on {}"
                                      .format(', '.join(missing), self.name))
 
+    def ifs(self):
+        self.require_cmds('ip')
+        info = json.loads(self.output('ip -j link show'))
+        return [i['ifname'] for i in info]
+
 
 class SiteTasst(Tasst):
     """
@@ -90,6 +96,10 @@ class SiteTasst(Tasst):
                 status = proc.wait()
                 self.assertNotEquals(status, 0)
 
+    def test_has_lo(self):
+        with self.setup_site() as site:
+            self.assertIn('lo', site.ifs())
+
 
 # Represents the host on which the tests are running, as opposed to
 # some simulated host created by the tests
-- 
2.40.1