Two new verbs are added: "generate" and "upload". The first one just
creates a "report", i.e. puts the metrics into a structured JSON object
that in the future is intended to carry additional data like a
signature:
$ build/systemd-report generate io.systemd.Manager.UnitsTotal
{
"mediaType" : "application/vnd.io.systemd.report",
"timestamp" : "Tue 2026-04-28 22:30:09 UTC",
"metrics" : [
{
"name" : "io.systemd.Manager.UnitsTotal",
"value" : 520
}
]
}
The second verb can be used to upload or otherwise process the report.
It builds on the code added in 0a8560eed8.
In /run/systemd/metrics-upload/ we expect a set of sockets. We'll call
out to each one of them. This allows the data to be processed in custom
ways, incl. writing to storage or sending over the network.
Each socket must provide a single interface:
io.systemd.Metrics.Upload {"report":$data}
This gets rid of the duality in the cmdline interface and various
APIs. The general plan is collect both "facts" and "metrics" in a
single list. We have various producers which respond on the
io.systemd.Facts endpoint. Those will need to be adjusted to respond
to io.systemd.Metrics.
Cmdline interface:
'metrics' (unchanged)
'describe-metrics' → 'describe'
'facts' → merged into 'metrics'
'describe-facts' → merged into 'describe'
Let's prepare for a future where the "systemd-report" tool can do more
than enumerate metrics: let's introduce our usual "verbs" style
interface.
Let's also add a second command right-away: "describe-metrics" shows the
description of the metrics.
Zbigniew Jędrzejewski-Szmek
Yu Watanabe
Lennart Poettering