metrics: dump the error metrics during failure

Fix the assertion to print a more useful message when an error metric is
non-zero. Also, make sure that we upload metrics to CloudWatch even when
there is a non-zero error metric.

Signed-off-by: Babis Chalios <[email protected]>
Co-authored-by: Patrick Roy <[email protected]>

Author: bchalios

tests/host_tools/fcmetrics.py

@@ -8,6 +8,7 @@
 """
 
 import datetime
+import json
 import math
 import platform
 import time
@@ -463,14 +464,15 @@ def flatten_dict(node, prefix: str):
             continue
         metrics.put_metric(key, value, get_emf_unit_for_fc_metrics(key))
 
-    assert not {
+    metrics.flush()
+
+    failure_metrics = {
         key: value
         for key, value in flattened_metrics.items()
         if "err" in key or "fail" in key or "panic" in key or "num_faults" in key
         if value
     }
-
-    metrics.flush()
+    assert not failure_metrics, json.dumps(failure_metrics, indent=1)
 
 
 class FCMetricsMonitor(Thread):