MetricsList not working with no-name metrics.

The following code sample is breaking for me when attempting to instantiate a metricslist object

pc = PrometheusConnect(
    url="my_prometheus_instance",
    headers={"Authorization":"bearer my_private_token" },
    disable_ssl=True,
    )

end_time = datetime.datetime.now()
start_time = end_time - datetime.timedelta(days=365)

chunk_size = parse_timedelta("now", "1d")

query_result = pc.custom_query(query='avg_over_time(min(up{job=~"foo"})[7d:])*100')

bar=MetricsList(query_result)

This is the output of the code in question

bar=MetricsList(foo)

for item in bar:

    print(item.metric_name, item.label_config)

    print(item.metric_values)

---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-12-6b7c63e24b2a> in <module>
----> 1 bar=MetricsList(foo)
      2 for item in bar:
      3     print(item.metric_name, item.label_config)
      4     print(item.metric_values)

/opt/app-root/lib/python3.6/site-packages/prometheus_api_client/metrics_list.py in __init__(self, metric_data_list)
     40                         metric_object_list.append(metric_object)
     41             else:
---> 42                 metric_object = Metric(i)
     43                 if metric_object in metric_object_list:
     44                     metric_object_list[metric_object_list.index(metric_object)] += metric_object

/opt/app-root/lib/python3.6/site-packages/prometheus_api_client/metric.py in __init__(self, metric, oldest_data_datetime)
     68             self.oldest_data_datetime = oldest_data_datetime
     69         else:
---> 70             self.metric_name = metric["metric"]["__name__"]
     71             self.label_config = deepcopy(metric["metric"])
     72             self.oldest_data_datetime = oldest_data_datetime

KeyError: '__name__'

The value of query_result is [{'metric': {}, 'value': [1566485171.497, '14735']}]

My guess is that any prometheus query that returns a time_series without a name will break. Setting a default value of some sort is probably the simplest solution here.

[anushkrishnav]

Can I work on this ?

[stefancrain]

For the next person who comes across this, I think I’ve found some success. In my query I was able to use label_replace to insert a label where there wasn’t one.

Updating the example above :

query_result = pc.custom_query(query='label_replace(avg_over_time(min(up{job=~"foo"})[7d:])*100), '__name__', 'baz', 'job', '.*')')

… which doesn’t run for me so here’s mine:

end_time = datetime.now()
start_time = end_time - timedelta(days=30)

query_result = pc.custom_query_range(
    query="label_replace(max(max_over_time(container_memory_max_usage_bytes[1d])) by (pod_name), '__name__', 'baz', 'job', '.*')"
    start_time=start_time,
    end_time=end_time,
    step = 60*60*24
)