Prometheus Metric Exposition Generator

The format Prometheus reads is plain text and deceptively strict: one help line, one type line and one per sample. It looks like something you can assemble by concatenating strings, and that is where the metric starts being rejected by the collector with nobody understanding why — almost always over a character the grammar does not accept.

Fill in name, type, help text and value, and the page assembles the block while validating what matters. The name has its own grammar: it starts with a letter, underscore or colon, and continues with those plus digits. Hyphens, spaces and accents make the line invalid — and the hyphen is the commonest mistake from people coming from other metric systems, where it is conventional.

The page also flags the naming conventions, which are not mandatory but matter to whoever reads the dashboard later: counters end in total, duration metrics end in seconds with the unit in the name, and the counter suffix should not appear on a gauge. The unit belongs in the name because Prometheus stores it nowhere else — if it is not there, nobody knows whether that number is milliseconds or seconds.