tests: iproute2 VRF capability check for topotests

tests/topotests/bgp_multi_vrf_topo1/test_bgp_multi_vrf_topo1.py

@@ -115,7 +115,7 @@
 # Import topogen and topotest helpers
 from lib.topogen import Topogen, get_topogen
 from mininet.topo import Topo
-
+from lib.topotest import iproute2_is_vrf_capable
 from lib.common_config import (
     step,
     verify_rib,
@@ -215,6 +215,10 @@ def setup_module(mod):
     if result is not True:
         pytest.skip("Kernel requirements are not met")
 
+    # iproute2 needs to support VRFs for this suite to run.
+    if not iproute2_is_vrf_capable():
+        pytest.skip("Installed iproute2 version does not support VRFs")
+
     testsuite_run_time = time.asctime(time.localtime(time.time()))
     logger.info("Testsuite start time: {}".format(testsuite_run_time))
     logger.info("=" * 40)

tests/topotests/bgp_multi_vrf_topo2/test_bgp_multi_vrf_topo2.py

@@ -71,7 +71,7 @@
 # Import topogen and topotest helpers
 from lib.topogen import Topogen, get_topogen
 from mininet.topo import Topo
-
+from lib.topotest import iproute2_is_vrf_capable
 from lib.common_config import (
     step,
     verify_rib,
@@ -164,6 +164,10 @@ def setup_module(mod):
     if result is not True:
         pytest.skip("Kernel requirements are not met")
 
+    # iproute2 needs to support VRFs for this suite to run.
+    if not iproute2_is_vrf_capable():
+        pytest.skip("Installed iproute2 version does not support VRFs")
+
     testsuite_run_time = time.asctime(time.localtime(time.time()))
     logger.info("Testsuite start time: {}".format(testsuite_run_time))
     logger.info("=" * 40)

tests/topotests/isis-topo1-vrf/test_isis_topo1_vrf.py

@@ -40,6 +40,8 @@
 from lib import topotest
 from lib.topogen import Topogen, TopoRouter, get_topogen
 from lib.topolog import logger
+from lib.topotest import iproute2_is_vrf_capable
+from lib.common_config import required_linux_kernel_version
 
 from mininet.topo import Topo
 
@@ -193,18 +195,21 @@ def test_isis_route_installation():
 
 
 def test_isis_linux_route_installation():
-
-    dist = platform.dist()
-
-    if dist[1] == "16.04":
-        pytest.skip("Kernel not supported for vrf")
-
     "Check whether all expected routes are present and installed in the OS"
     tgen = get_topogen()
     # Don't run this test if we have any failure.
     if tgen.routers_have_failure():
         pytest.skip(tgen.errors)
 
+    # Required linux kernel version for this suite to run.
+    result = required_linux_kernel_version("4.15")
+    if result is not True:
+        pytest.skip("Kernel requirements are not met")
+
+    # iproute2 needs to support VRFs for this suite to run.
+    if not iproute2_is_vrf_capable():
+        pytest.skip("Installed iproute2 version does not support VRFs")
+
     logger.info("Checking routers for installed ISIS vrf routes in OS")
     # Check for routes in `ip route show vrf {}-cust1`
     for rname, router in tgen.routers().items():
@@ -236,18 +241,21 @@ def test_isis_route6_installation():
 
 
 def test_isis_linux_route6_installation():
-
-    dist = platform.dist()
-
-    if dist[1] == "16.04":
-        pytest.skip("Kernel not supported for vrf")
-
     "Check whether all expected routes are present and installed in the OS"
     tgen = get_topogen()
     # Don't run this test if we have any failure.
     if tgen.routers_have_failure():
         pytest.skip(tgen.errors)
 
+    # Required linux kernel version for this suite to run.
+    result = required_linux_kernel_version("4.15")
+    if result is not True:
+        pytest.skip("Kernel requirements are not met")
+
+    # iproute2 needs to support VRFs for this suite to run.
+    if not iproute2_is_vrf_capable():
+        pytest.skip("Installed iproute2 version does not support VRFs")
+
     logger.info("Checking routers for installed ISIS vrf IPv6 routes in OS")
     # Check for routes in `ip -6 route show vrf {}-cust1`
     for rname, router in tgen.routers().items():

tests/topotests/lib/topotest.py

@@ -516,6 +516,44 @@ def normalize_text(text):
     return text
 
 
+def is_linux():
+    """
+    Parses unix name output to check if running on GNU/Linux.
+
+    Returns True if running on Linux, returns False otherwise.
+    """
+
+    if os.uname()[0] == "Linux":
+        return True
+    return False
+
+
+def iproute2_is_vrf_capable():
+    """
+    Checks if the iproute2 version installed on the system is capable of
+    handling VRFs by interpreting the output of the 'ip' utility found in PATH.
+
+    Returns True if capability can be detected, returns False otherwise.
+    """
+
+    if is_linux():
+        try:
+            subp = subprocess.Popen(
+                ["ip", "route", "show", "vrf"],
+                stdout=subprocess.PIPE,
+                stderr=subprocess.PIPE,
+                stdin=subprocess.PIPE,
+                encoding="utf-8"
+            )
+            iproute2_err = subp.communicate()[1].splitlines()[0].split()[0]
+
+            if iproute2_err != "Error:":
+                return True
+        except Exception:
+            pass
+    return False
+
+
 def module_present_linux(module, load):
     """
     Returns whether `module` is present.