mirror of https://github.com/prometheus/prometheus
Browse Source
* Don't panic if we try to release a string that is not in the interner. * Move seriesMtx locking in QueueManager's StoreSeries function. This stops us from calling release for strings that aren't interned if there's a race between reading a checkpoint and storing new series labels, which could happen during checkpointing or reloading config. Signed-off-by: Callum Styan <callumstyan@gmail.com>pull/5503/head
Callum Styan
6 years ago
committed by
Brian Brazil
5 changed files with 237 additions and 3 deletions
@ -0,0 +1,187 @@
|
||||
// Copyright 2018 The Prometheus Authors
|
||||
// Licensed under the Apache License, Version 2.0 (the "License");
|
||||
// you may not use this file except in compliance with the License.
|
||||
// You may obtain a copy of the License at
|
||||
//
|
||||
// http://www.apache.org/licenses/LICENSE-2.0
|
||||
//
|
||||
// Unless required by applicable law or agreed to in writing, software
|
||||
// distributed under the License is distributed on an "AS IS" BASIS,
|
||||
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
// See the License for the specific language governing permissions and
|
||||
// limitations under the License.
|
||||
|
||||
// Package testutil provides helpers to test code using the prometheus package
|
||||
// of client_golang.
|
||||
//
|
||||
// While writing unit tests to verify correct instrumentation of your code, it's
|
||||
// a common mistake to mostly test the instrumentation library instead of your
|
||||
// own code. Rather than verifying that a prometheus.Counter's value has changed
|
||||
// as expected or that it shows up in the exposition after registration, it is
|
||||
// in general more robust and more faithful to the concept of unit tests to use
|
||||
// mock implementations of the prometheus.Counter and prometheus.Registerer
|
||||
// interfaces that simply assert that the Add or Register methods have been
|
||||
// called with the expected arguments. However, this might be overkill in simple
|
||||
// scenarios. The ToFloat64 function is provided for simple inspection of a
|
||||
// single-value metric, but it has to be used with caution.
|
||||
//
|
||||
// End-to-end tests to verify all or larger parts of the metrics exposition can
|
||||
// be implemented with the CollectAndCompare or GatherAndCompare functions. The
|
||||
// most appropriate use is not so much testing instrumentation of your code, but
|
||||
// testing custom prometheus.Collector implementations and in particular whole
|
||||
// exporters, i.e. programs that retrieve telemetry data from a 3rd party source
|
||||
// and convert it into Prometheus metrics.
|
||||
package testutil |
||||
|
||||
import ( |
||||
"bytes" |
||||
"fmt" |
||||
"io" |
||||
|
||||
"github.com/prometheus/common/expfmt" |
||||
|
||||
dto "github.com/prometheus/client_model/go" |
||||
|
||||
"github.com/prometheus/client_golang/prometheus" |
||||
"github.com/prometheus/client_golang/prometheus/internal" |
||||
) |
||||
|
||||
// ToFloat64 collects all Metrics from the provided Collector. It expects that
|
||||
// this results in exactly one Metric being collected, which must be a Gauge,
|
||||
// Counter, or Untyped. In all other cases, ToFloat64 panics. ToFloat64 returns
|
||||
// the value of the collected Metric.
|
||||
//
|
||||
// The Collector provided is typically a simple instance of Gauge or Counter, or
|
||||
// – less commonly – a GaugeVec or CounterVec with exactly one element. But any
|
||||
// Collector fulfilling the prerequisites described above will do.
|
||||
//
|
||||
// Use this function with caution. It is computationally very expensive and thus
|
||||
// not suited at all to read values from Metrics in regular code. This is really
|
||||
// only for testing purposes, and even for testing, other approaches are often
|
||||
// more appropriate (see this package's documentation).
|
||||
//
|
||||
// A clear anti-pattern would be to use a metric type from the prometheus
|
||||
// package to track values that are also needed for something else than the
|
||||
// exposition of Prometheus metrics. For example, you would like to track the
|
||||
// number of items in a queue because your code should reject queuing further
|
||||
// items if a certain limit is reached. It is tempting to track the number of
|
||||
// items in a prometheus.Gauge, as it is then easily available as a metric for
|
||||
// exposition, too. However, then you would need to call ToFloat64 in your
|
||||
// regular code, potentially quite often. The recommended way is to track the
|
||||
// number of items conventionally (in the way you would have done it without
|
||||
// considering Prometheus metrics) and then expose the number with a
|
||||
// prometheus.GaugeFunc.
|
||||
func ToFloat64(c prometheus.Collector) float64 { |
||||
var ( |
||||
m prometheus.Metric |
||||
mCount int |
||||
mChan = make(chan prometheus.Metric) |
||||
done = make(chan struct{}) |
||||
) |
||||
|
||||
go func() { |
||||
for m = range mChan { |
||||
mCount++ |
||||
} |
||||
close(done) |
||||
}() |
||||
|
||||
c.Collect(mChan) |
||||
close(mChan) |
||||
<-done |
||||
|
||||
if mCount != 1 { |
||||
panic(fmt.Errorf("collected %d metrics instead of exactly 1", mCount)) |
||||
} |
||||
|
||||
pb := &dto.Metric{} |
||||
m.Write(pb) |
||||
if pb.Gauge != nil { |
||||
return pb.Gauge.GetValue() |
||||
} |
||||
if pb.Counter != nil { |
||||
return pb.Counter.GetValue() |
||||
} |
||||
if pb.Untyped != nil { |
||||
return pb.Untyped.GetValue() |
||||
} |
||||
panic(fmt.Errorf("collected a non-gauge/counter/untyped metric: %s", pb)) |
||||
} |
||||
|
||||
// CollectAndCompare registers the provided Collector with a newly created
|
||||
// pedantic Registry. It then does the same as GatherAndCompare, gathering the
|
||||
// metrics from the pedantic Registry.
|
||||
func CollectAndCompare(c prometheus.Collector, expected io.Reader, metricNames ...string) error { |
||||
reg := prometheus.NewPedanticRegistry() |
||||
if err := reg.Register(c); err != nil { |
||||
return fmt.Errorf("registering collector failed: %s", err) |
||||
} |
||||
return GatherAndCompare(reg, expected, metricNames...) |
||||
} |
||||
|
||||
// GatherAndCompare gathers all metrics from the provided Gatherer and compares
|
||||
// it to an expected output read from the provided Reader in the Prometheus text
|
||||
// exposition format. If any metricNames are provided, only metrics with those
|
||||
// names are compared.
|
||||
func GatherAndCompare(g prometheus.Gatherer, expected io.Reader, metricNames ...string) error { |
||||
got, err := g.Gather() |
||||
if err != nil { |
||||
return fmt.Errorf("gathering metrics failed: %s", err) |
||||
} |
||||
if metricNames != nil { |
||||
got = filterMetrics(got, metricNames) |
||||
} |
||||
var tp expfmt.TextParser |
||||
wantRaw, err := tp.TextToMetricFamilies(expected) |
||||
if err != nil { |
||||
return fmt.Errorf("parsing expected metrics failed: %s", err) |
||||
} |
||||
want := internal.NormalizeMetricFamilies(wantRaw) |
||||
|
||||
return compare(got, want) |
||||
} |
||||
|
||||
// compare encodes both provided slices of metric families into the text format,
|
||||
// compares their string message, and returns an error if they do not match.
|
||||
// The error contains the encoded text of both the desired and the actual
|
||||
// result.
|
||||
func compare(got, want []*dto.MetricFamily) error { |
||||
var gotBuf, wantBuf bytes.Buffer |
||||
enc := expfmt.NewEncoder(&gotBuf, expfmt.FmtText) |
||||
for _, mf := range got { |
||||
if err := enc.Encode(mf); err != nil { |
||||
return fmt.Errorf("encoding gathered metrics failed: %s", err) |
||||
} |
||||
} |
||||
enc = expfmt.NewEncoder(&wantBuf, expfmt.FmtText) |
||||
for _, mf := range want { |
||||
if err := enc.Encode(mf); err != nil { |
||||
return fmt.Errorf("encoding expected metrics failed: %s", err) |
||||
} |
||||
} |
||||
|
||||
if wantBuf.String() != gotBuf.String() { |
||||
return fmt.Errorf(` |
||||
metric output does not match expectation; want: |
||||
|
||||
%s |
||||
got: |
||||
|
||||
%s`, wantBuf.String(), gotBuf.String()) |
||||
|
||||
} |
||||
return nil |
||||
} |
||||
|
||||
func filterMetrics(metrics []*dto.MetricFamily, names []string) []*dto.MetricFamily { |
||||
var filtered []*dto.MetricFamily |
||||
for _, m := range metrics { |
||||
for _, name := range names { |
||||
if m.GetName() == name { |
||||
filtered = append(filtered, m) |
||||
break |
||||
} |
||||
} |
||||
} |
||||
return filtered |
||||
} |
||||
Loading…
Reference in new issue