Development

The exporter is a Go program using the Prometheus SDK.

External contributions are welcome, see CONTRIBUTING for details.

The exporter initialization is as follows:

• Parse flags options and configuration properties
• Load the default toml file (default-metrics.toml) and store each metric in a Metric struct
• Load the custom toml file (if a custom toml file is given)
• Create an Exporter object
• Register exporter in prometheus library
• Launching a web server to handle incoming requests
• Attempt connection to any configured Oracle Database servers

These operations are mainly done in the main function.

After this initialization phase, the exporter will wait for the arrival of a request.

Each time, it will iterate over the content of the metricsToScrape structure (in the function scrape func (e * Export) scrape (ch chan <- prometheus.Metric)).

For each element (of Metric type), a call to the ScrapeMetric function will be made which will itself make a call to the ScrapeGenericValues function.

The ScrapeGenericValues function will read the information from the Metric structure and, depending on the parameters, will generate the metrics to return. In particular, it will use the GeneratePrometheusMetrics function which will make SQL calls to the database.

Docker/container build

To build a container image, run the following command:

make docker

For ARM:

make docker-arm

Building Binaries

Run build:

make go-build

This will create binaries and archives inside the dist folder for the building operating system.