test(metrics): Test aggregate and per block metrics

Add test to validate aggregate block metrics.

Signed-off-by: Sudan Landge <sudanl@amazon.com>

tests/integration_tests/functional/test_metrics.py

@@ -370,3 +370,25 @@ def test_net_metrics(test_microvm_with_api):
         # test that we get metrics while interacting with different interfaces
         net_metrics.validate(test_microvm)
         assert exit_code == 0
+
+def test_block_metrics(test_microvm_with_api):
+    """
+    Validate that NetDeviceMetrics doesn't have a breaking change
+    and "net" is aggregate of all "net_*" in the json object.
+    """
+    test_microvm = test_microvm_with_api
+    test_microvm.spawn()
+
+    # Set up a basic microVM.
+    test_microvm.basic_config()
+
+    num_block_devices = 1
+    block_metrics = FcDeviceMetrics("block", num_block_devices)
+
+    test_microvm.start()
+
+    # check that the started microvm has "block" and "NUM_NET_DEVICES" number of "block_" metrics
+    block_metrics.validate(test_microvm)
+
+    for i in range(num_block_devices):
+        block_metrics.validate(test_microvm)