Contributing

Prometheus uses GitHub to manage reviews of pull requests.

• If you have a trivial fix or improvement, go ahead and create a pull request, addressing (with @...) the maintainer of this repository (see MAINTAINERS.md) in the description of the pull request.

• If you plan to do something more involved, first discuss your ideas on our mailing list. This will avoid unnecessary work and surely give you and us a good deal of inspiration.

• Relevant coding style guidelines are the Go Code Review Comments and the Formatting and style section of Peter Bourgon's Go: Best Practices for Production Environments.

• Sign your work to certify that your changes were created by yourself or you have the right to submit it under our license. Read https://developercertificate.org/ for all details and append your sign-off to every commit message like this:

    Signed-off-by: Random J Developer <example@example.com>

Collector Implementation Guidelines

The Node Exporter is not a general monitoring agent. Its sole purpose is to expose machine metrics, as oppose to service metrics, with the only exception being the textfile collector.

The metrics should not get transformed in a way that is hardware specific and would require maintaining any form of vendor based mappings or conditions. If for example a proc file contains the magic number 42 as some identifier, the Node Exporter should expose it as it is and not keep a mapping in code to make this human readable. Instead, the textfile collector can be used to add a static metric which can be joined with the metrics exposed by the exporter to get human readable identifier.

A Collector may only read /proc or /sys files, use system calls or local sockets to retrieve metrics. It may not require root privileges. Running external commands is not allowed for performance and reliability reasons. Use a dedicated exporter instead or gather the metrics via the textfile collector.

The Node Exporter tries to support the most common machine metrics. For more exotic metrics, use the textfile collector or a dedicated Exporter.