Change default provider to Ember

[rossf7]

Towards #7

Adds support for the Ember provider and makes it the default.

go run .

curl -s http://localhost:8000/metrics | grep grid | head
# HELP grid_intensity_carbon_actual Actual carbon intensity for the electricity grid in this region.
# TYPE grid_intensity_carbon_actual gauge
grid_intensity_carbon_actual{provider="ember-climate.org",region="ARG"} 365.292
grid_intensity_carbon_actual{provider="ember-climate.org",region="ARM"} 206.522
grid_intensity_carbon_actual{provider="ember-climate.org",region="AUS"} 526.876
grid_intensity_carbon_actual{provider="ember-climate.org",region="AUT"} 145.083
grid_intensity_carbon_actual{provider="ember-climate.org",region="AZE"} 536.585
grid_intensity_carbon_actual{provider="ember-climate.org",region="BDI"} 275.862
grid_intensity_carbon_actual{provider="ember-climate.org",region="BEL"} 156.063
grid_intensity_carbon_actual{provider="ember-climate.org",region="BGD"} 559.606

Or for a single country

GRID_INTENSITY_REGION=ESP go run .

curl -s http://localhost:8000/metrics | grep grid | head
# HELP grid_intensity_carbon_actual Actual carbon intensity for the electricity grid in this region.
# TYPE grid_intensity_carbon_actual gauge
grid_intensity_carbon_actual{provider="ember-climate.org",region="ESP"} 193.737

Or using the carbonintensity.org.uk provider

GRID_INTENSITY_PROVIDER=carbonintensity.org.uk go run .

curl -s http://localhost:8000/metrics | grep grid | head
# HELP grid_intensity_carbon_actual Actual carbon intensity for the electricity grid in this region.
# TYPE grid_intensity_carbon_actual gauge
grid_intensity_carbon_actual{provider="carbonintensity.org.uk",region="UK"} 197

[rossf7]

The integration test was failing.

This upgrades the Kubernetes version we test with from 1.19 to 1.24 and means the test will pass 🤷‍♂️

[rossf7]

Needs thegreenwebfoundation/grid-intensity-go#24 to be merged and released

[rossf7]

Region is now optional so we need this extra templating.

[rossf7]

This is the new logic to return all countries if a region is not provided.

[mrchrisadams]

Hey Ross, given that:

• electricity map doesn't support iterating through multiple countries any more
• the carbonintensityku provider is focussed on the uk

Do you think it's better to just have the exporter list a single country?

The data from ember is very unlikely to change, and I can't think of a use case where you would be listing all the countries for prometheus to consume, because previously the library is been a bit like allowing a computer to say:

this is my carbon intensity based on where I am in the world, and what time it is

I'm happy to defer to you on this though, as I'm not a heavy user or grafana / prometheus.

[mrchrisadams]

I have one query about whether regions should be optional, but I'm prepared to follow the use cases you have in mind here Ross, and otherwise I'm happy for this to be merged in. Danke!

[rossf7]

Do you think it's better to just have the exporter list a single country?

The data from ember is very unlikely to change, and I can't think of a use case where you would be listing all the countries for prometheus to consume, because previously the library is been a bit like allowing a computer to say:

Good point, I'll remove the changes listing all countries. I also don't have a good use case for it right now.

My thinking was about the dev experience. So the user wouldn't need to provide any configuration and could later select the country they are interested in.

But I think it's better and simpler 😅 to provide example install commands with a country and the user can change to their value.