test: verify VETH pairs can be removed

Verify a VETH pair can be removed after a couple of dummy operations to
step the dagger generation past the initial where the pair is created.

NOTE: Infamy currenly lacks support for removing chunks of configuraion
      e.g., a dut.del_config_dict(), or similar, and delete_xpath() is
      not valid for configurations with dependencies like VETH pairs.

Issue #658

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

test/case/ietf_interfaces/ietf_interfaces.yaml

@@ -26,6 +26,9 @@
 - name: bridge_vlan
   case: bridge_vlan/test.py
 
+- name: veth_delete
+  case: veth_delete/test.py
+
 - name: ipv4_autoconf
   case: ipv4_autoconf/test.py
 

test/case/ietf_interfaces/veth_delete/Readme.adoc

@@ -0,0 +1,35 @@
+=== Verify that VETH pairs can be deleted
+==== Description
+```
+     veth0b       veth0a        e1    e2
+          `---------'
+```
+
+Each test step to create, add address, or delete an interace is distinct
+from any other step.  This to trigger a new configuration "generation".
+
+==== Topology
+ifdef::topdoc[]
+image::../../test/case/ietf_interfaces/veth_delete/topology.png[Verify that VETH pairs can be deleted topology]
+endif::topdoc[]
+ifndef::topdoc[]
+ifdef::testgroup[]
+image::veth_delete/topology.png[Verify that VETH pairs can be deleted topology]
+endif::testgroup[]
+ifndef::testgroup[]
+image::topology.png[Verify that VETH pairs can be deleted topology]
+endif::testgroup[]
+endif::topdoc[]
+==== Test sequence
+. Initialize
+. Create VETH pair
+. Verify VETH pair exists
+. Set IP address on target:eth0 (dummy op)
+. Set IP address on target:eth1 (dummy op)
+. Reset configuration
+. Verify target:eth0 and target:eth1 still exist
+. Verify VETH pair have been removed
+
+
+<<<
+

test/case/ietf_interfaces/veth_delete/test.py

@@ -0,0 +1,111 @@
+#!/usr/bin/env python3
+"""Verify that VETH pairs can be deleted
+
+```
+     veth0b       veth0a        e1    e2
+          `---------'
+```
+
+Each test step to create, add address, or delete an interace is distinct
+from any other step.  This to trigger a new configuration "generation".
+
+"""
+
+import infamy
+import infamy.iface as iface
+
+
+with infamy.Test() as test:
+    with test.step("Initialize"):
+        env = infamy.Env()
+        target = env.attach("target", "mgmt")
+
+        _, eth0 = env.ltop.xlate("target", "eth0")
+        _, eth1 = env.ltop.xlate("target", "eth1")
+
+        veth0a = "veth0a"
+        veth0b = "veth0b"
+
+    with test.step("Create VETH pair"):
+        target.put_config_dict("ietf-interfaces", {
+            "interfaces": {
+                "interface": [
+                    {
+                        "name": veth0a,
+                        "type": "infix-if-type:veth",
+                        "enabled": True,
+                        "infix-interfaces:veth": {
+                            "peer": veth0b
+                        }
+                    },
+                    {
+                        "name": veth0b,
+                        "type": "infix-if-type:veth",
+                        "enabled": True,
+                        "infix-interfaces:veth": {
+                            "peer": veth0a
+                        }
+                    }
+                ]
+            }
+        })
+
+    with test.step("Verify VETH pair exists"):
+        assert iface.interface_exist(target, veth0a), \
+            f"Interface <{veth0a}> does not exist."
+        assert iface.interface_exist(target, veth0b), \
+            f"Interface <{veth0b}> does not exist."
+
+    with test.step("Set IP address on target:eth0 (dummy op)"):
+        target.put_config_dict("ietf-interfaces", {
+            "interfaces": {
+                "interface": [{
+                    "name": f"{eth0}",
+                    "ipv4": {
+                        "address": [{
+                            "ip": "10.0.0.1",
+                            "prefix-length": 24
+                        }]
+                    }
+                }]
+            }
+        })
+
+    with test.step("Set IP address on target:eth1 (dummy op)"):
+        target.put_config_dict("ietf-interfaces", {
+            "interfaces": {
+                "interface": [{
+                    "name": f"{eth1}",
+                    "ipv4": {
+                        "address": [{
+                            "ip": "20.0.0.1",
+                            "prefix-length": 24
+                        }]
+                    }
+                }]
+            }
+        })
+
+    # TODO: need target.del_config_dict() or similar for VETH _pairs_,
+    #       because both interfaces must be removed at the same time.
+    # with test.step("Delete VETH pair"):
+    #     xpath = f"/ietf-interfaces:interfaces/interface[name='{veth0a}']"
+    #     target.delete_xpath(xpath)
+    # XXX: temporary workaround
+    with test.step("Reset configuration"):
+        # Calls target.test_reset() to apply safe-config
+        target = env.attach("target", "mgmt")
+
+    with test.step("Verify target:eth0 and target:eth1 still exist"):
+        assert iface.interface_exist(target, eth0), \
+            f"Interface {eth0} missing!"
+        assert iface.interface_exist(target, eth1), \
+            f"Interface {eth1} missing!"
+
+    with test.step("Verify VETH pair have been removed"):
+        assert not iface.interface_exist(target, veth0a), \
+            f"Interface <{veth0a}> still exists!"
+        assert not iface.interface_exist(target, veth0b), \
+            f"Interface <{veth0b}> still exists!"
+
+    test.succeed()

test/case/ietf_interfaces/veth_delete/topology.dot

@@ -0,0 +1,25 @@
+graph "1x3" {
+	layout="neato";
+	overlap="false";
+	esep="+80";
+
+        node [shape=record, fontname="monospace"];
+	edge [color="cornflowerblue", penwidth="2"];
+
+	host [
+	    label="host | { <tgt> tgt | <dummy0> dummy0 | <dummy1> dummy1 }",
+	    pos="0,12!",
+	    kind="controller",
+	];
+
+        target [
+	    label="{ <mgmt> mgmt | <eth0> eth0 | <eth1> eth1 } | target",
+	    pos="10,12!",
+
+	    kind="infix",
+	];
+
+	host:tgt -- target:mgmt [kind=mgmt]
+	host:dummy0 -- target:eth0 [color=black]
+	host:dummy1 -- target:eth1 [color=black]
+}