single_metric() to inherit default dimensions

[prudnikov]

Use case

At the root level I define default metric which is environment name in my case.

metrics = Metrics()
metrics.set_default_dimensions(Environment=ENVIRONMENT)

This is all fine and Environment gets propagated to all metrics. However, when single_metric() is used this default dimension is ignored. This is what I do to overcome that.

metrics = Metrics()

with single_metric(
    name="Metric1", unit=MetricUnit.Milliseconds, value=elapsed_ms
) as this_metric:
    this_metric.add_dimension(name="TableName", value=self.table_name)


    for name, value in metrics.default_dimensions.items():
        this_metric.add_dimension(name=name, value=value)

or it should be possible with this_metric.default_dimensions = metrics.default_dimensions, I did not tried this.

This way all the default dimensions are propagated with a single metric.

Solution/User Experience

When creating a SingleMetric with single_metric context manager default dimensions should be copied to a SingleMetric instance.

I can imagine the situation when you don't want to propagate default dimensions to the SingleMetric.

To keep existing usage untouched I suppose the default behavior should be to not propagate default dimensions. So the solution can be the additional keyword argument inherit_default_dimensions: bool = False

with single_metric("Name", MetricUnit.Count, 1, inherit_default_dimensions=True) as this_metric:
    this_metric.add_dimension(name="Dim1", value="Val")

Alternative solutions

No response

Acknowledgment

• This feature request meets Lambda Powertools Tenets
• Should this be considered in other Lambda Powertools languages? i.e. Java, TypeScript

[boring-cyborg]

Thanks for opening your first issue here! We'll come back to you as soon as we can.
In the meantime, check out the #python channel on our AWS Lambda Powertools Discord: Invite link

[prudnikov]

I'll be happy to contribute to this feature.

[rubenfonseca]

Hi @prudnikov thank you so much for opening this issue, it's very well written and very clear! We would be happy to merge your contribution and this feature. Kudos!

[rubenfonseca]

Hi @prudnikov do you have the time to submit a PR for this issue? We would love to review it and merge it :)

[prudnikov]

@rubenfonseca I'll try to finish this today.
By they way, this will require extracting of SingleMetric and single_metric to a separate module. I'll create single_metric.py and move them to this module. Otherwise there is a circular import. I need to use Metrics inside the single_metric

[prudnikov]

I just created a PR, I changed design a little bit, my motivation for that is described in the PR.

[github-actions]

⚠️COMMENT VISIBILITY WARNING⚠️

This issue is now closed. Please be mindful that future comments are hard for our team to see.

If you need more assistance, please either tag a team member or open a new issue that references this one.

If you wish to keep having a conversation with other community members under this issue feel free to do so.