[PATCH v3 11/20] avocado/tasst: Helper for creating veth devices between namespaces

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

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 avocado/tasst/meta/__init__.py | 16 +++++++++++++
 avocado/tasst/meta/veth.py     | 43 ++++++++++++++++++++++++++++++++++
 avocado/tasst/nstool.py        | 10 ++++++++
 3 files changed, 69 insertions(+)
 create mode 100644 avocado/tasst/meta/__init__.py
 create mode 100644 avocado/tasst/meta/veth.py

diff --git a/avocado/tasst/meta/__init__.py b/avocado/tasst/meta/__init__.py
new file mode 100644
index 0000000..6582554
--- /dev/null
+++ b/avocado/tasst/meta/__init__.py
@@ -0,0 +1,16 @@
+#! /usr/bin/python3
+
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# tasst - Test A Simple Socket Transport
+#         library of test helpers for passt & pasta
+#
+# tasst/meta - Test pieces of the test infrastructure.
+#
+# Usually, tests for the test infrastructure should go next to the
+# implementation of the thing being tested.  Sometimes that's not
+# possible (usually because it would cause a circular module
+# dependency).  In that case those tests can go here.
+#
+# Copyright Red Hat
+# Author: David Gibson <david@gibson.dropbear.id.au>
diff --git a/avocado/tasst/meta/veth.py b/avocado/tasst/meta/veth.py
new file mode 100644
index 0000000..c4cdcf7
--- /dev/null
+++ b/avocado/tasst/meta/veth.py
@@ -0,0 +1,43 @@
+#! /usr/bin/python3
+
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# tasst - Test A Simple Socket Transport
+#         library of test helpers for passt & pasta
+#
+# tasst/metatest/veth - Test the veth creation helper
+#
+# These test code from tasst.site, but require additional support from
+# tasst.nstool.
+#
+# Copyright Red Hat
+# Author: David Gibson <david@gibson.dropbear.id.au>
+
+import contextlib
+
+import avocado
+
+from tasst import Tasst
+from tasst.site import REAL_HOST
+from tasst.nstool import UnshareSite
+
+
+class VethTasst(Tasst):
+    """
+    Test helpers for creating veths between namespaces
+
+    :avocado: tags=meta
+    """
+
+    @contextlib.contextmanager
+    def setup_veth(self):
+        with UnshareSite(type(self).__name__ + '.1', '-Un') as ns1:
+            with UnshareSite(type(self).__name__ + '.2', '-n',
+                             parent=ns1, sudo=True) as ns2:
+                ns1.veth('veth1', 'veth2', ns2)
+                yield (ns1, ns2)
+
+    def test_ifs(self):
+        with self.setup_veth() as (ns1, ns2):
+            self.assertCountEqual(ns1.ifs(), ['lo', 'veth1'])
+            self.assertCountEqual(ns2.ifs(), ['lo', 'veth2'])
diff --git a/avocado/tasst/nstool.py b/avocado/tasst/nstool.py
index 50598a5..6f1d96b 100644
--- a/avocado/tasst/nstool.py
+++ b/avocado/tasst/nstool.py
@@ -68,6 +68,16 @@ class NsToolSite(Site):
     def bg(self, cmd, sudo=False, **kwargs):
         return REAL_HOST.bg(self._nst_cmd(cmd, sudo), **kwargs)
 
+    def veth(self, ifname, peername, peer=None):
+        self.fg('ip link add {} type veth peer name {}'.format(ifname, peername),
+                sudo=True)
+        if peer is not None:
+            if not isinstance(peer, NsToolSite):
+                raise TypeError
+            self.fg('ip link set {} netns {}'.format(peername,
+                                                     peer.relative_pid(self)),
+                    sudo=True)
+
 
 # Create path for temporary nstool Unix socket
 #
-- 
@@ -68,6 +68,16 @@ class NsToolSite(Site):
     def bg(self, cmd, sudo=False, **kwargs):
         return REAL_HOST.bg(self._nst_cmd(cmd, sudo), **kwargs)
 
+    def veth(self, ifname, peername, peer=None):
+        self.fg('ip link add {} type veth peer name {}'.format(ifname, peername),
+                sudo=True)
+        if peer is not None:
+            if not isinstance(peer, NsToolSite):
+                raise TypeError
+            self.fg('ip link set {} netns {}'.format(peername,
+                                                     peer.relative_pid(self)),
+                    sudo=True)
+
 
 # Create path for temporary nstool Unix socket
 #
-- 
2.40.1