The tool should not be considered stable, and those things we usually
place in /usr/lib/systemd, and not in $PATH.
We can move that to $PATH once we are confident it's gonna stay the way
it is.
Let's also rename the "metric_prefix" to "name", because it's actually
the servce name, and by giving it this generic name we can use it
reasonably in log messages.
Let's stay close to Varlink's naming rules and insist that metrics
prefixes must be valid varlink interface names, and suffixes are valid
varlink field names.
The former rule is clear: because a metric <x>.<y> can only be provided
by a varlink service <x>, it is obvious we should validate them the
same way. Validating the suffix via varlink field rules is not that
obvious, but I think it makes sense to stay close to Varlink naming
rules if we already started out at one place.
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.
Let's count how many sources we skip, and output that as a summary, and
return an error exit code in this case.
Let's also put a limit on the metrics collected, not just the sources.
Also, our macros that put limits on things are usually called XYZ_MAX,
follow the same scheme here.
Let's also move the Varlink connection management into the Context
object. Let's also switch to Set* for it, so that we get get
auto-expanding behaviour.
It's one of the primary objects that make up the program "context"
conceptually, hence it also should be part of the Context object. This
allows us to just have it available if the Context object is seen.
We should permit that the report varlink dir is created on the fly when
the first socket is bound there. Hence, let's treat a non-existant dir
equivalent to an empty one.
We usually do this in our tree like this, do it here too.
Mike Yuan
Lennart Poettering
Ivan Kruglov
Zbigniew Jędrzejewski-Szmek
Zbigniew Jędrzejewski-Szmek
Yaping Li