Add tests to verify priority of device list from mounts vs. envvar

Signed-off-by: Kevin Klues <kklues@nvidia.com>

pkg/container_test.go

@@ -538,6 +538,86 @@ func TestGetDevicesFromMounts(t *testing.T) {
 	}
 }
 
+func TestDeviceListSourcePriority(t *testing.T) {
+	var tests = []struct {
+		description        string
+		mountDevices       []Mount
+		envvarDevices      string
+		privileged         bool
+		acceptUnprivileged bool
+		expectedDevices    *string
+		expectedPanic      bool
+	}{
+		{
+			description: "Mount devices, unprivileged, no accept unprivileged",
+			mountDevices: []Mount{
+				{
+					Source:      "/dev/null",
+					Destination: filepath.Join(defaultDeviceListVolumeMount, "GPU0"),
+				},
+				{
+					Source:      "/dev/null",
+					Destination: filepath.Join(defaultDeviceListVolumeMount, "GPU1"),
+				},
+			},
+			envvarDevices:      "GPU2,GPU3",
+			privileged:         false,
+			acceptUnprivileged: false,
+			expectedDevices:    &[]string{"GPU0,GPU1"}[0],
+		},
+		{
+			description:        "No mount devices, unprivileged, no accept unprivileged",
+			mountDevices:       nil,
+			envvarDevices:      "GPU0,GPU1",
+			privileged:         false,
+			acceptUnprivileged: false,
+			expectedPanic:      true,
+		},
+		{
+			description:        "No mount devices, privileged, no accept unprivileged",
+			mountDevices:       nil,
+			envvarDevices:      "GPU0,GPU1",
+			privileged:         true,
+			acceptUnprivileged: false,
+			expectedDevices:    &[]string{"GPU0,GPU1"}[0],
+		},
+		{
+			description:        "No mount devices, unprivileged, accept unprivileged",
+			mountDevices:       nil,
+			envvarDevices:      "GPU0,GPU1",
+			privileged:         false,
+			acceptUnprivileged: true,
+			expectedDevices:    &[]string{"GPU0,GPU1"}[0],
+		},
+	}
+	for _, tc := range tests {
+		t.Run(tc.description, func(t *testing.T) {
+			// Wrap the call to getDevices() in a closure.
+			var devices *string
+			getDevices := func() {
+				env := map[string]string{
+					envNVVisibleDevices: tc.envvarDevices,
+				}
+				hookConfig := getDefaultHookConfig()
+				hookConfig.AcceptEnvvarUnprivileged = tc.acceptUnprivileged
+				devices = getDevices(&hookConfig, env, tc.mountDevices, tc.privileged, false)
+			}
+
+			// For any tests that are expected to panic, make sure they do.
+			if tc.expectedPanic {
+				mustPanic(t, getDevices)
+				return
+			}
+
+			// For all other tests, just grab the devices and check the results
+			getDevices()
+			if !reflect.DeepEqual(devices, tc.expectedDevices) {
+				t.Errorf("Unexpected devices (got: %v, wanted: %v)", *devices, *tc.expectedDevices)
+			}
+		})
+	}
+}
+
 func elementsMatch(slice0, slice1 []string) bool {
 	map0 := make(map[string]int)
 	map1 := make(map[string]int)