This disables the custom metrics API when no custom metrics rules are
given (the resource metrics API acts equivalently). This allows a given
adapter to serve only one of the APIs, if desired.
This introduces support for the resource metrics in the adapter.
The individual queries and window sizes are fully customizable via a new
config section. This uses just the generic machinery from
metrics-server to serve the API.
This commit introduces advanced configuration. The rate-interval and
label-prefix flags are removed, and replaced by a configuration file
that allows you to specify series queries and the rules for transforming
those into metrics queries and API resources.
Currently, the adapter uses http.DefaultClient to access Prometheus.
This means that it does support using TLS client certificates, custom
CA certificates, or token-base authentication, which are all common
setups when connecting to Prometheus behind an auth proxy.
This commit adds support for using a separate kubeconfig, or in-cluster
config, to configure auth when connecting to Prometheus.
Fixes #52
[directxman12: cleanups, spelling corrections, and slight refactor]
This allows setting a prefix on the labels used to determine which
resources a series belongs to. The prefix may be set using the
`--label-prefix` flag.
This updates the dependencies to be compatible with Kubernetes 1.8,
including the new custom.metrics.k8s.io/v1beta1 API group and the
corresponding custom-metrics-apiserver changes.
Currently, we fetch the discovery information once at the start of
of the adapter, and then never update it. This could prove problematic,
since other API servers might come only after the adapter is started up.
The boilerplate contains a periodically updating RESTMapper that solves
this issue by refreshing the discovery information at an interval (as
specified by a flag), so that we have a chance to fetch new resources.
This causes the Prometheus provider to take a stop channel as an
argument, which allows us to stop the lister (which keeps the series list
up to date) in the unit tests.
k8s.io/custom-metrics-boilerplate was "renamed" to
"github.com/directxman12/custom-metrics-boilerplate". This updates all
references to point to the correct location.
This commit instruments prometheus query times by prometheus endpoint,
allowing us to see how quickly prometheus answers the queries that
back the custom-metrics API endpoints.
The initial functionality works. There's still a number of TODOs to
clean up, and some edge cases to work around, and some errors that could
be handled better.
