adding-a-new-scraper.md

Adding a new scraper type

This guide walks you through the process of adding a new scraper type.

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📢 Before implementing a new scraping type, please open an issue to discuss your scenario

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Samples

Provide a sample configuration in samples\promitor-sample.yaml.

Configuration

1. Add your new scraping type to ResourceType
2. Describe what your configuration by creating <New-Type>MetricDefinitionand inherit from MetricDefinition
3. Update the deserialization to support your new type in MetricsDeserializer
4. Provide a unit test that tests the deserialization based on our sample

Going forward in this guide, TMetricDefinition will refer to your newly created configuration type.

Validation

For every scraper type we provide validation for the configuration so that Promitor fails to start up.

This requires the following steps:

1. Create a new validator that implements IMetricValidator<TMetricDefinition>
2. Hook your new validator in our validation pipeline in MetricsValidator
3. Provide a unit test for every validation rule that was added

Scraping

1. Implement a scraper that inherits from Scraper<TMetricDefinition>. This one will specify how to call Azure Monitor.
2. Hook your new scraper in our MetricScraperFactory which determines what scraper to use for the passed configuration

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📝 Currently we don't have integration tests

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Documentation

Features are great to have but without clear & well-written documentation they are somewhat useless.

It would be good if you could provide documentation on the following:

1. What Azure service it supports and how to use it
2. What fields need to be configured and what they are for
3. An example configuration

This should be provided in a new file under docs\configuration\metrics.