Merge ~ltrager/maas:enable_vnic_characteristics_on_s390x into maas:master

[Lee Trager]

Automatically enable VNIC characteristics on S390X when deploying a VM host

S390X partitions do not forward packets over bridges by default. To allow
packet forward VNIC characteristics must be enabled. Do this by default
when a VM host is deployed.

[MAAS Lander (maas-lander)]

UNIT TESTS
-b enable_vnic_characteristics_on_s390x lp:~ltrager/maas/+git/maas into -b master lp:~maas-committers/maas

STATUS: SUCCESS
COMMIT: 32e91beee705559183f74408858169aee68ed940

review: Approve

[Björn Tillenius (bjornt)]

Looks good to me, but please see comment inline.

review: Approve

diff --git a/src/metadataserver/tests/test_vendor_data.py b/src/metadataserver/tests/test_vendor_data.py
index 3fd39d4..cc9288f 100644
--- a/src/metadataserver/tests/test_vendor_data.py
+++ b/src/metadataserver/tests/test_vendor_data.py
@@ -422,7 +422,54 @@ class TestGenerateKVMPodConfiguration(MAASServerTestCase):
                     {
                         "path": "/etc/rc.local",
                         "content": (
-                            "#!/bin/sh\n" "ppc64_cpu --smt=off\n" "exit 0\n"
+                            "#!/bin/sh\n"
+                            "# This file was generated by MAAS to disable SMT "
+                            "on PPC64EL since\n"
+                            "# VMs are not supported otherwise.\n"
+                            "ppc64_cpu --smt=off\n"
+                            "exit 0\n"
+                        ),
+                        "permissions": "0755",
+                    },
+                ],
+            ),
+            config,
+        )
+        self.assertIn(("runcmd", ["/etc/rc.local"]), config)
+
+    def test_enables_vnic_characteristics_on_s390x(self):
+        password = "123secure"
+        self.patch(vendor_data, "_generate_password").return_value = password
+        node = factory.make_Node(
+            status=NODE_STATUS.DEPLOYING,
+            osystem="ubuntu",
+            netboot=False,
+            architecture="s390x/generic",
+            register_vmhost=True,
+        )
+        config = list(generate_kvm_pod_configuration(node))
+        self.assertIn(
+            (
+                "write_files",
+                [
+                    {
+                        "path": "/etc/rc.local",
+                        "content": (
+                            "#!/bin/bash\n"
+                            "# This file was generated by MAAS to enable VNIC "
+                            "characteristics to allow\n"
+                            "# packets to be forwarded over a bridge.\n"
+                            'for bridge in $(bridge link show | awk -F"[ :]" '
+                            "'{ print $3 }'); do\n"
+                            "    # Isolated networks are not associated with "
+                            "a qeth and do not need\n"
+                            "    # anything enabled. Ignore them.\n"
+                            "    phy_addr=$(lsqeth $bridge 2>/dev/null | "
+                            "awk -F ': ' '/cdev0/ {print $2}')\n"
+                            '    if [ -n "$phy_addr" ]; then\n'
+                            "        chzdev $phy_addr vnicc/learning=1\n"
+                            "    fi\n"
+                            "done\n"
                         ),
                         "permissions": "0755",
                     },
diff --git a/src/metadataserver/vendor_data.py b/src/metadataserver/vendor_data.py
index 8236e8e..81092df 100644
--- a/src/metadataserver/vendor_data.py
+++ b/src/metadataserver/vendor_data.py
@@ -251,19 +251,41 @@ def generate_kvm_pod_configuration(node):
             },
         ]
 
-    # disable SMT on ppc64el since VMs are not supported otherwise
     if arch == "ppc64el":
+        rc_script = dedent(
+            """\
+            #!/bin/sh
+            # This file was generated by MAAS to disable SMT on PPC64EL since
+            # VMs are not supported otherwise.
+            ppc64_cpu --smt=off
+            exit 0
+            """
+        )
+    elif arch == "s390x":
+        rc_script = dedent(
+            """\
+            #!/bin/bash
+            # This file was generated by MAAS to enable VNIC characteristics to allow
+            # packets to be forwarded over a bridge.
+            for bridge in $(bridge link show | awk -F"[ :]" '{ print $3 }'); do
+                # Isolated networks are not associated with a qeth and do not need
+                # anything enabled. Ignore them.
+                phy_addr=$(lsqeth $bridge 2>/dev/null | awk -F ': ' '/cdev0/ {print $2}')
+                if [ -n "$phy_addr" ]; then
+                    chzdev $phy_addr vnicc/learning=1
+                fi
+            done
+            """
+        )
+    else:
+        rc_script = None
+
+    if rc_script:
         rc_local = "/etc/rc.local"
         yield "write_files", [
             {
                 "path": rc_local,
-                "content": dedent(
-                    """\
-                    #!/bin/sh
-                    ppc64_cpu --smt=off
-                    exit 0
-                    """
-                ),
+                "content": rc_script,
                 "permissions": "0755",
             },
         ]