Add the capability to lint MetricFamilies directly

Also, change all the `dto.MetricFamily` arguments to pointers to be
more consistent with what we do in client_golang in general.

Signed-off-by: beorn7 <beorn@grafana.com>
This commit is contained in:
beorn7 2020-04-24 23:42:49 +02:00
parent a3a59237d1
commit 6433bcf819
1 changed files with 38 additions and 25 deletions

View File

@ -30,6 +30,7 @@ import (
// names, types, and metadata, and reports them to the caller. // names, types, and metadata, and reports them to the caller.
type Linter struct { type Linter struct {
r io.Reader r io.Reader
mfs []*dto.MetricFamily
} }
// A Problem is an issue detected by a Linter. // A Problem is an issue detected by a Linter.
@ -42,33 +43,41 @@ type Problem struct {
} }
// newProblem is helper function to create a Problem. // newProblem is helper function to create a Problem.
func newProblem(mf dto.MetricFamily, text string) Problem { func newProblem(mf *dto.MetricFamily, text string) Problem {
return Problem{ return Problem{
Metric: mf.GetName(), Metric: mf.GetName(),
Text: text, Text: text,
} }
} }
// New creates a new Linter that reads an input stream of Prometheus metrics. // New creates a new Linter that reads an input stream of Prometheus metrics in
// Only the Prometheus text exposition format is supported. // the Prometheus text exposition format.
func New(r io.Reader) *Linter { func New(r io.Reader) *Linter {
return &Linter{ return &Linter{
r: r, r: r,
} }
} }
// NewWithMetricFamilies creates a new Linter that reads from a slice of
// MetricFamily protobuf messages.
func NewWithMetricFamilies(mfs []*dto.MetricFamily) *Linter {
return &Linter{
mfs: mfs,
}
}
// Lint performs a linting pass, returning a slice of Problems indicating any // Lint performs a linting pass, returning a slice of Problems indicating any
// issues found in the metrics stream. The slice is sorted by metric name // issues found in the metrics stream. The slice is sorted by metric name
// and issue description. // and issue description.
func (l *Linter) Lint() ([]Problem, error) { func (l *Linter) Lint() ([]Problem, error) {
// TODO(mdlayher): support for protobuf exposition format?
d := expfmt.NewDecoder(l.r, expfmt.FmtText)
var problems []Problem var problems []Problem
var mf dto.MetricFamily if l.r != nil {
d := expfmt.NewDecoder(l.r, expfmt.FmtText)
mf := &dto.MetricFamily{}
for { for {
if err := d.Decode(&mf); err != nil { if err := d.Decode(mf); err != nil {
if err == io.EOF { if err == io.EOF {
break break
} }
@ -78,6 +87,10 @@ func (l *Linter) Lint() ([]Problem, error) {
problems = append(problems, lint(mf)...) problems = append(problems, lint(mf)...)
} }
}
for _, mf := range l.mfs {
problems = append(problems, lint(mf)...)
}
// Ensure deterministic output. // Ensure deterministic output.
sort.SliceStable(problems, func(i, j int) bool { sort.SliceStable(problems, func(i, j int) bool {
@ -91,8 +104,8 @@ func (l *Linter) Lint() ([]Problem, error) {
} }
// lint is the entry point for linting a single metric. // lint is the entry point for linting a single metric.
func lint(mf dto.MetricFamily) []Problem { func lint(mf *dto.MetricFamily) []Problem {
fns := []func(mf dto.MetricFamily) []Problem{ fns := []func(mf *dto.MetricFamily) []Problem{
lintHelp, lintHelp,
lintMetricUnits, lintMetricUnits,
lintCounter, lintCounter,
@ -113,7 +126,7 @@ func lint(mf dto.MetricFamily) []Problem {
} }
// lintHelp detects issues related to the help text for a metric. // lintHelp detects issues related to the help text for a metric.
func lintHelp(mf dto.MetricFamily) []Problem { func lintHelp(mf *dto.MetricFamily) []Problem {
var problems []Problem var problems []Problem
// Expect all metrics to have help text available. // Expect all metrics to have help text available.
@ -125,7 +138,7 @@ func lintHelp(mf dto.MetricFamily) []Problem {
} }
// lintMetricUnits detects issues with metric unit names. // lintMetricUnits detects issues with metric unit names.
func lintMetricUnits(mf dto.MetricFamily) []Problem { func lintMetricUnits(mf *dto.MetricFamily) []Problem {
var problems []Problem var problems []Problem
unit, base, ok := metricUnits(*mf.Name) unit, base, ok := metricUnits(*mf.Name)
@ -146,7 +159,7 @@ func lintMetricUnits(mf dto.MetricFamily) []Problem {
// lintCounter detects issues specific to counters, as well as patterns that should // lintCounter detects issues specific to counters, as well as patterns that should
// only be used with counters. // only be used with counters.
func lintCounter(mf dto.MetricFamily) []Problem { func lintCounter(mf *dto.MetricFamily) []Problem {
var problems []Problem var problems []Problem
isCounter := mf.GetType() == dto.MetricType_COUNTER isCounter := mf.GetType() == dto.MetricType_COUNTER
@ -165,7 +178,7 @@ func lintCounter(mf dto.MetricFamily) []Problem {
// lintHistogramSummaryReserved detects when other types of metrics use names or labels // lintHistogramSummaryReserved detects when other types of metrics use names or labels
// reserved for use by histograms and/or summaries. // reserved for use by histograms and/or summaries.
func lintHistogramSummaryReserved(mf dto.MetricFamily) []Problem { func lintHistogramSummaryReserved(mf *dto.MetricFamily) []Problem {
// These rules do not apply to untyped metrics. // These rules do not apply to untyped metrics.
t := mf.GetType() t := mf.GetType()
if t == dto.MetricType_UNTYPED { if t == dto.MetricType_UNTYPED {
@ -206,7 +219,7 @@ func lintHistogramSummaryReserved(mf dto.MetricFamily) []Problem {
} }
// lintMetricTypeInName detects when metric types are included in the metric name. // lintMetricTypeInName detects when metric types are included in the metric name.
func lintMetricTypeInName(mf dto.MetricFamily) []Problem { func lintMetricTypeInName(mf *dto.MetricFamily) []Problem {
var problems []Problem var problems []Problem
n := strings.ToLower(mf.GetName()) n := strings.ToLower(mf.GetName())
@ -224,7 +237,7 @@ func lintMetricTypeInName(mf dto.MetricFamily) []Problem {
} }
// lintReservedChars detects colons in metric names. // lintReservedChars detects colons in metric names.
func lintReservedChars(mf dto.MetricFamily) []Problem { func lintReservedChars(mf *dto.MetricFamily) []Problem {
var problems []Problem var problems []Problem
if strings.Contains(mf.GetName(), ":") { if strings.Contains(mf.GetName(), ":") {
problems = append(problems, newProblem(mf, "metric names should not contain ':'")) problems = append(problems, newProblem(mf, "metric names should not contain ':'"))
@ -235,7 +248,7 @@ func lintReservedChars(mf dto.MetricFamily) []Problem {
var camelCase = regexp.MustCompile(`[a-z][A-Z]`) var camelCase = regexp.MustCompile(`[a-z][A-Z]`)
// lintCamelCase detects metric names and label names written in camelCase. // lintCamelCase detects metric names and label names written in camelCase.
func lintCamelCase(mf dto.MetricFamily) []Problem { func lintCamelCase(mf *dto.MetricFamily) []Problem {
var problems []Problem var problems []Problem
if camelCase.FindString(mf.GetName()) != "" { if camelCase.FindString(mf.GetName()) != "" {
problems = append(problems, newProblem(mf, "metric names should be written in 'snake_case' not 'camelCase'")) problems = append(problems, newProblem(mf, "metric names should be written in 'snake_case' not 'camelCase'"))
@ -252,7 +265,7 @@ func lintCamelCase(mf dto.MetricFamily) []Problem {
} }
// lintUnitAbbreviations detects abbreviated units in the metric name. // lintUnitAbbreviations detects abbreviated units in the metric name.
func lintUnitAbbreviations(mf dto.MetricFamily) []Problem { func lintUnitAbbreviations(mf *dto.MetricFamily) []Problem {
var problems []Problem var problems []Problem
n := strings.ToLower(mf.GetName()) n := strings.ToLower(mf.GetName())
for _, s := range unitAbbreviations { for _, s := range unitAbbreviations {