Collector builder functions are only used internally in the `collector`
package, and shouldn't needlessly be exposed as part of the package API
to downstream clients.
Signed-off-by: Ben Reedy <breed808@breed808.com>
Behaviour of init functions has been centralised in `collector/init.go`,
and can be called during exporter startup. This allows the exporter to
control the timing of collector initialisation, rather than relying on
the import & `init()` method.
This should reduce unexpected behaviour arising from the use of
`init()`, such as #551.
Signed-off-by: Ben Reedy <breed808@breed808.com>
Bumps [github.com/alecthomas/kingpin](https://github.com/alecthomas/kingpin) from
v2.2.6 to v2.3.2.
This also changes the upstream package name from
gopkg.in/alecthomas/kingpin.v2 to github.com/alecthomas/kingpin/v2 which
is required by the upstream exporter-toolkit package.
Signed-off-by: Ben Reedy <breed808@breed808.com>
