openmetrics 0.3.0

Breaking Changes

• Label names should now be passed as the labels parameter when creating a metric, instead of being inferred from the remaining named arguments. For consistency with other clients, there is no longer a notion of a "default" label value. This also makes it possible to have labels like name, help, type, and so on that conflict with existing parameter names.

• Relatedly, all labels must now be specified when calling methods on a metric (such as inc() or set()), since there is no default to fall back on.

Other Improvements

• The package now has its own hex logo.

• Only generate the OpenMetrics format when the (preliminary) OpenMetrics content-type is passed in the Accept header. Otherwise, fall back on the Prometheus format and content-type (#3).

• Pushgateway functions will now stop() for HTTP errors instead of merely issuing a warning. Clients that can tolerate these errors will likely tryCatch() them anyway, since httr::RETRY() can fail for other reasons.

• Requests made to Shiny apps that return HTTP 401 will no longer include the rendered metrics anyway.

• The ", \n, and \ characters are now escaped in labels and help text, as in the OpenMetrics reference implementation (#1).

• Counter metrics can now be incremented by zero.

• Counter, Gauge, and Histogram metrics can now take an optional unit parameter. The provided unit must match the one in the name of the metric itself -- e.g. a received_bytes metric must have unit "bytes" (#2).

• Counters and Histograms now have a _created child metric, as per the OpenMetrics draft specification (#2).