Add support for custom validations in promlint (#1311)

* Refactor promlint validation structure

Signed-off-by: João Vilaça <jvilaca@redhat.com>

* Add support for custom validations in promlint

Signed-off-by: João Vilaça <jvilaca@redhat.com>

* Keep backwards compatibility

Signed-off-by: João Vilaça <jvilaca@redhat.com>

---------

Signed-off-by: João Vilaça <jvilaca@redhat.com>
This commit is contained in:
João Vilaça 2023-10-10 10:38:10 +01:00 committed by GitHub
parent 486d514e63
commit 60a85133ed
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
9 changed files with 501 additions and 289 deletions

View File

@ -0,0 +1,33 @@
// Copyright 2020 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 promlint
import dto "github.com/prometheus/client_model/go"
// A Problem is an issue detected by a linter.
type Problem struct {
// The name of the metric indicated by this Problem.
Metric string
// A description of the issue for this Problem.
Text string
}
// newProblem is helper function to create a Problem.
func newProblem(mf *dto.MetricFamily, text string) Problem {
return Problem{
Metric: mf.GetName(),
Text: text,
}
}

View File

@ -16,15 +16,11 @@ package promlint
import ( import (
"errors" "errors"
"fmt"
"io" "io"
"regexp"
"sort" "sort"
"strings"
"github.com/prometheus/common/expfmt"
dto "github.com/prometheus/client_model/go" dto "github.com/prometheus/client_model/go"
"github.com/prometheus/common/expfmt"
) )
// A Linter is a Prometheus metrics linter. It identifies issues with metric // A Linter is a Prometheus metrics linter. It identifies issues with metric
@ -37,23 +33,8 @@ type Linter struct {
// of them. // of them.
r io.Reader r io.Reader
mfs []*dto.MetricFamily mfs []*dto.MetricFamily
}
// A Problem is an issue detected by a Linter. customValidations []Validation
type Problem struct {
// The name of the metric indicated by this Problem.
Metric string
// A description of the issue for this Problem.
Text string
}
// newProblem is helper function to create a Problem.
func newProblem(mf *dto.MetricFamily, text string) Problem {
return Problem{
Metric: mf.GetName(),
Text: text,
}
} }
// New creates a new Linter that reads an input stream of Prometheus metrics in // New creates a new Linter that reads an input stream of Prometheus metrics in
@ -72,6 +53,14 @@ func NewWithMetricFamilies(mfs []*dto.MetricFamily) *Linter {
} }
} }
// AddCustomValidations adds custom validations to the linter.
func (l *Linter) AddCustomValidations(vs ...Validation) {
if l.customValidations == nil {
l.customValidations = make([]Validation, 0, len(vs))
}
l.customValidations = append(l.customValidations, vs...)
}
// 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.
@ -91,11 +80,11 @@ func (l *Linter) Lint() ([]Problem, error) {
return nil, err return nil, err
} }
problems = append(problems, lint(mf)...) problems = append(problems, l.lint(mf)...)
} }
} }
for _, mf := range l.mfs { for _, mf := range l.mfs {
problems = append(problems, lint(mf)...) problems = append(problems, l.lint(mf)...)
} }
// Ensure deterministic output. // Ensure deterministic output.
@ -110,276 +99,25 @@ 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 (l *Linter) lint(mf *dto.MetricFamily) []Problem {
fns := []func(mf *dto.MetricFamily) []Problem{ var problems []Problem
lintHelp,
lintMetricUnits, for _, fn := range defaultValidations {
lintCounter, errs := fn(mf)
lintHistogramSummaryReserved, for _, err := range errs {
lintMetricTypeInName, problems = append(problems, newProblem(mf, err.Error()))
lintReservedChars, }
lintCamelCase,
lintUnitAbbreviations,
} }
var problems []Problem if l.customValidations != nil {
for _, fn := range fns { for _, fn := range l.customValidations {
problems = append(problems, fn(mf)...) errs := fn(mf)
for _, err := range errs {
problems = append(problems, newProblem(mf, err.Error()))
}
}
} }
// TODO(mdlayher): lint rules for specific metrics types. // TODO(mdlayher): lint rules for specific metrics types.
return problems return problems
} }
// lintHelp detects issues related to the help text for a metric.
func lintHelp(mf *dto.MetricFamily) []Problem {
var problems []Problem
// Expect all metrics to have help text available.
if mf.Help == nil {
problems = append(problems, newProblem(mf, "no help text"))
}
return problems
}
// lintMetricUnits detects issues with metric unit names.
func lintMetricUnits(mf *dto.MetricFamily) []Problem {
var problems []Problem
unit, base, ok := metricUnits(*mf.Name)
if !ok {
// No known units detected.
return nil
}
// Unit is already a base unit.
if unit == base {
return nil
}
problems = append(problems, newProblem(mf, fmt.Sprintf("use base unit %q instead of %q", base, unit)))
return problems
}
// lintCounter detects issues specific to counters, as well as patterns that should
// only be used with counters.
func lintCounter(mf *dto.MetricFamily) []Problem {
var problems []Problem
isCounter := mf.GetType() == dto.MetricType_COUNTER
isUntyped := mf.GetType() == dto.MetricType_UNTYPED
hasTotalSuffix := strings.HasSuffix(mf.GetName(), "_total")
switch {
case isCounter && !hasTotalSuffix:
problems = append(problems, newProblem(mf, `counter metrics should have "_total" suffix`))
case !isUntyped && !isCounter && hasTotalSuffix:
problems = append(problems, newProblem(mf, `non-counter metrics should not have "_total" suffix`))
}
return problems
}
// lintHistogramSummaryReserved detects when other types of metrics use names or labels
// reserved for use by histograms and/or summaries.
func lintHistogramSummaryReserved(mf *dto.MetricFamily) []Problem {
// These rules do not apply to untyped metrics.
t := mf.GetType()
if t == dto.MetricType_UNTYPED {
return nil
}
var problems []Problem
isHistogram := t == dto.MetricType_HISTOGRAM
isSummary := t == dto.MetricType_SUMMARY
n := mf.GetName()
if !isHistogram && strings.HasSuffix(n, "_bucket") {
problems = append(problems, newProblem(mf, `non-histogram metrics should not have "_bucket" suffix`))
}
if !isHistogram && !isSummary && strings.HasSuffix(n, "_count") {
problems = append(problems, newProblem(mf, `non-histogram and non-summary metrics should not have "_count" suffix`))
}
if !isHistogram && !isSummary && strings.HasSuffix(n, "_sum") {
problems = append(problems, newProblem(mf, `non-histogram and non-summary metrics should not have "_sum" suffix`))
}
for _, m := range mf.GetMetric() {
for _, l := range m.GetLabel() {
ln := l.GetName()
if !isHistogram && ln == "le" {
problems = append(problems, newProblem(mf, `non-histogram metrics should not have "le" label`))
}
if !isSummary && ln == "quantile" {
problems = append(problems, newProblem(mf, `non-summary metrics should not have "quantile" label`))
}
}
}
return problems
}
// lintMetricTypeInName detects when metric types are included in the metric name.
func lintMetricTypeInName(mf *dto.MetricFamily) []Problem {
var problems []Problem
n := strings.ToLower(mf.GetName())
for i, t := range dto.MetricType_name {
if i == int32(dto.MetricType_UNTYPED) {
continue
}
typename := strings.ToLower(t)
if strings.Contains(n, "_"+typename+"_") || strings.HasSuffix(n, "_"+typename) {
problems = append(problems, newProblem(mf, fmt.Sprintf(`metric name should not include type '%s'`, typename)))
}
}
return problems
}
// lintReservedChars detects colons in metric names.
func lintReservedChars(mf *dto.MetricFamily) []Problem {
var problems []Problem
if strings.Contains(mf.GetName(), ":") {
problems = append(problems, newProblem(mf, "metric names should not contain ':'"))
}
return problems
}
var camelCase = regexp.MustCompile(`[a-z][A-Z]`)
// lintCamelCase detects metric names and label names written in camelCase.
func lintCamelCase(mf *dto.MetricFamily) []Problem {
var problems []Problem
if camelCase.FindString(mf.GetName()) != "" {
problems = append(problems, newProblem(mf, "metric names should be written in 'snake_case' not 'camelCase'"))
}
for _, m := range mf.GetMetric() {
for _, l := range m.GetLabel() {
if camelCase.FindString(l.GetName()) != "" {
problems = append(problems, newProblem(mf, "label names should be written in 'snake_case' not 'camelCase'"))
}
}
}
return problems
}
// lintUnitAbbreviations detects abbreviated units in the metric name.
func lintUnitAbbreviations(mf *dto.MetricFamily) []Problem {
var problems []Problem
n := strings.ToLower(mf.GetName())
for _, s := range unitAbbreviations {
if strings.Contains(n, "_"+s+"_") || strings.HasSuffix(n, "_"+s) {
problems = append(problems, newProblem(mf, "metric names should not contain abbreviated units"))
}
}
return problems
}
// metricUnits attempts to detect known unit types used as part of a metric name,
// e.g. "foo_bytes_total" or "bar_baz_milligrams".
func metricUnits(m string) (unit, base string, ok bool) {
ss := strings.Split(m, "_")
for _, s := range ss {
if base, found := units[s]; found {
return s, base, true
}
for _, p := range unitPrefixes {
if strings.HasPrefix(s, p) {
if base, found := units[s[len(p):]]; found {
return s, base, true
}
}
}
}
return "", "", false
}
// Units and their possible prefixes recognized by this library. More can be
// added over time as needed.
var (
// map a unit to the appropriate base unit.
units = map[string]string{
// Base units.
"amperes": "amperes",
"bytes": "bytes",
"celsius": "celsius", // Also allow Celsius because it is common in typical Prometheus use cases.
"grams": "grams",
"joules": "joules",
"kelvin": "kelvin", // SI base unit, used in special cases (e.g. color temperature, scientific measurements).
"meters": "meters", // Both American and international spelling permitted.
"metres": "metres",
"seconds": "seconds",
"volts": "volts",
// Non base units.
// Time.
"minutes": "seconds",
"hours": "seconds",
"days": "seconds",
"weeks": "seconds",
// Temperature.
"kelvins": "kelvin",
"fahrenheit": "celsius",
"rankine": "celsius",
// Length.
"inches": "meters",
"yards": "meters",
"miles": "meters",
// Bytes.
"bits": "bytes",
// Energy.
"calories": "joules",
// Mass.
"pounds": "grams",
"ounces": "grams",
}
unitPrefixes = []string{
"pico",
"nano",
"micro",
"milli",
"centi",
"deci",
"deca",
"hecto",
"kilo",
"kibi",
"mega",
"mibi",
"giga",
"gibi",
"tera",
"tebi",
"peta",
"pebi",
}
// Common abbreviations that we'd like to discourage.
unitAbbreviations = []string{
"s",
"ms",
"us",
"ns",
"sec",
"b",
"kb",
"mb",
"gb",
"tb",
"pb",
"m",
"h",
"d",
}
)

View File

@ -19,6 +19,8 @@ import (
"strings" "strings"
"testing" "testing"
dto "github.com/prometheus/client_model/go"
"github.com/prometheus/client_golang/prometheus/testutil/promlint" "github.com/prometheus/client_golang/prometheus/testutil/promlint"
) )
@ -786,3 +788,55 @@ func runTests(t *testing.T, tests []test) {
}) })
} }
} }
func TestCustomValidations(t *testing.T) {
lintAndVerify := func(l *promlint.Linter, cv test) {
problems, err := l.Lint()
if err != nil {
t.Fatalf("unexpected error: %v", err)
}
if want, got := cv.problems, problems; !reflect.DeepEqual(want, got) {
t.Fatalf("unexpected problems:\n- want: %v\n- got: %v",
want, got)
}
}
prob := []promlint.Problem{
{
Metric: "mc_something_total",
Text: "expected metric name to start with 'memcached_'",
},
}
cv := test{
name: "metric without necessary prefix",
in: `
# HELP mc_something_total Test metric.
# TYPE mc_something_total counter
mc_something_total 10
`,
problems: nil,
}
prefixValidation := func(mf *dto.MetricFamily) []error {
if !strings.HasPrefix(mf.GetName(), "memcached_") {
return []error{fmt.Errorf("expected metric name to start with 'memcached_'")}
}
return nil
}
t.Helper()
t.Run(cv.name, func(t *testing.T) {
// no problems
l1 := promlint.New(strings.NewReader(cv.in))
lintAndVerify(l1, cv)
})
t.Run(cv.name, func(t *testing.T) {
// prefix problems
l2 := promlint.New(strings.NewReader(cv.in))
l2.AddCustomValidations(prefixValidation)
cv.problems = prob
lintAndVerify(l2, cv)
})
}

View File

@ -0,0 +1,33 @@
// Copyright 2020 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 promlint
import (
dto "github.com/prometheus/client_model/go"
"github.com/prometheus/client_golang/prometheus/testutil/promlint/validations"
)
type Validation = func(mf *dto.MetricFamily) []error
var defaultValidations = []Validation{
validations.LintHelp,
validations.LintMetricUnits,
validations.LintCounter,
validations.LintHistogramSummaryReserved,
validations.LintMetricTypeInName,
validations.LintReservedChars,
validations.LintCamelCase,
validations.LintUnitAbbreviations,
}

View File

@ -0,0 +1,40 @@
// Copyright 2020 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 validations
import (
"errors"
"strings"
dto "github.com/prometheus/client_model/go"
)
// LintCounter detects issues specific to counters, as well as patterns that should
// only be used with counters.
func LintCounter(mf *dto.MetricFamily) []error {
var problems []error
isCounter := mf.GetType() == dto.MetricType_COUNTER
isUntyped := mf.GetType() == dto.MetricType_UNTYPED
hasTotalSuffix := strings.HasSuffix(mf.GetName(), "_total")
switch {
case isCounter && !hasTotalSuffix:
problems = append(problems, errors.New(`counter metrics should have "_total" suffix`))
case !isUntyped && !isCounter && hasTotalSuffix:
problems = append(problems, errors.New(`non-counter metrics should not have "_total" suffix`))
}
return problems
}

View File

@ -0,0 +1,101 @@
// Copyright 2020 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 validations
import (
"errors"
"fmt"
"regexp"
"strings"
dto "github.com/prometheus/client_model/go"
)
var camelCase = regexp.MustCompile(`[a-z][A-Z]`)
// LintMetricUnits detects issues with metric unit names.
func LintMetricUnits(mf *dto.MetricFamily) []error {
var problems []error
unit, base, ok := metricUnits(*mf.Name)
if !ok {
// No known units detected.
return nil
}
// Unit is already a base unit.
if unit == base {
return nil
}
problems = append(problems, fmt.Errorf("use base unit %q instead of %q", base, unit))
return problems
}
// LintMetricTypeInName detects when metric types are included in the metric name.
func LintMetricTypeInName(mf *dto.MetricFamily) []error {
var problems []error
n := strings.ToLower(mf.GetName())
for i, t := range dto.MetricType_name {
if i == int32(dto.MetricType_UNTYPED) {
continue
}
typename := strings.ToLower(t)
if strings.Contains(n, "_"+typename+"_") || strings.HasSuffix(n, "_"+typename) {
problems = append(problems, fmt.Errorf(`metric name should not include type '%s'`, typename))
}
}
return problems
}
// LintReservedChars detects colons in metric names.
func LintReservedChars(mf *dto.MetricFamily) []error {
var problems []error
if strings.Contains(mf.GetName(), ":") {
problems = append(problems, errors.New("metric names should not contain ':'"))
}
return problems
}
// LintCamelCase detects metric names and label names written in camelCase.
func LintCamelCase(mf *dto.MetricFamily) []error {
var problems []error
if camelCase.FindString(mf.GetName()) != "" {
problems = append(problems, errors.New("metric names should be written in 'snake_case' not 'camelCase'"))
}
for _, m := range mf.GetMetric() {
for _, l := range m.GetLabel() {
if camelCase.FindString(l.GetName()) != "" {
problems = append(problems, errors.New("label names should be written in 'snake_case' not 'camelCase'"))
}
}
}
return problems
}
// LintUnitAbbreviations detects abbreviated units in the metric name.
func LintUnitAbbreviations(mf *dto.MetricFamily) []error {
var problems []error
n := strings.ToLower(mf.GetName())
for _, s := range unitAbbreviations {
if strings.Contains(n, "_"+s+"_") || strings.HasSuffix(n, "_"+s) {
problems = append(problems, errors.New("metric names should not contain abbreviated units"))
}
}
return problems
}

View File

@ -0,0 +1,32 @@
// Copyright 2020 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 validations
import (
"errors"
dto "github.com/prometheus/client_model/go"
)
// LintHelp detects issues related to the help text for a metric.
func LintHelp(mf *dto.MetricFamily) []error {
var problems []error
// Expect all metrics to have help text available.
if mf.Help == nil {
problems = append(problems, errors.New("no help text"))
}
return problems
}

View File

@ -0,0 +1,63 @@
// Copyright 2020 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 validations
import (
"errors"
"strings"
dto "github.com/prometheus/client_model/go"
)
// LintHistogramSummaryReserved detects when other types of metrics use names or labels
// reserved for use by histograms and/or summaries.
func LintHistogramSummaryReserved(mf *dto.MetricFamily) []error {
// These rules do not apply to untyped metrics.
t := mf.GetType()
if t == dto.MetricType_UNTYPED {
return nil
}
var problems []error
isHistogram := t == dto.MetricType_HISTOGRAM
isSummary := t == dto.MetricType_SUMMARY
n := mf.GetName()
if !isHistogram && strings.HasSuffix(n, "_bucket") {
problems = append(problems, errors.New(`non-histogram metrics should not have "_bucket" suffix`))
}
if !isHistogram && !isSummary && strings.HasSuffix(n, "_count") {
problems = append(problems, errors.New(`non-histogram and non-summary metrics should not have "_count" suffix`))
}
if !isHistogram && !isSummary && strings.HasSuffix(n, "_sum") {
problems = append(problems, errors.New(`non-histogram and non-summary metrics should not have "_sum" suffix`))
}
for _, m := range mf.GetMetric() {
for _, l := range m.GetLabel() {
ln := l.GetName()
if !isHistogram && ln == "le" {
problems = append(problems, errors.New(`non-histogram metrics should not have "le" label`))
}
if !isSummary && ln == "quantile" {
problems = append(problems, errors.New(`non-summary metrics should not have "quantile" label`))
}
}
}
return problems
}

View File

@ -0,0 +1,118 @@
// Copyright 2020 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 validations
import "strings"
// Units and their possible prefixes recognized by this library. More can be
// added over time as needed.
var (
// map a unit to the appropriate base unit.
units = map[string]string{
// Base units.
"amperes": "amperes",
"bytes": "bytes",
"celsius": "celsius", // Also allow Celsius because it is common in typical Prometheus use cases.
"grams": "grams",
"joules": "joules",
"kelvin": "kelvin", // SI base unit, used in special cases (e.g. color temperature, scientific measurements).
"meters": "meters", // Both American and international spelling permitted.
"metres": "metres",
"seconds": "seconds",
"volts": "volts",
// Non base units.
// Time.
"minutes": "seconds",
"hours": "seconds",
"days": "seconds",
"weeks": "seconds",
// Temperature.
"kelvins": "kelvin",
"fahrenheit": "celsius",
"rankine": "celsius",
// Length.
"inches": "meters",
"yards": "meters",
"miles": "meters",
// Bytes.
"bits": "bytes",
// Energy.
"calories": "joules",
// Mass.
"pounds": "grams",
"ounces": "grams",
}
unitPrefixes = []string{
"pico",
"nano",
"micro",
"milli",
"centi",
"deci",
"deca",
"hecto",
"kilo",
"kibi",
"mega",
"mibi",
"giga",
"gibi",
"tera",
"tebi",
"peta",
"pebi",
}
// Common abbreviations that we'd like to discourage.
unitAbbreviations = []string{
"s",
"ms",
"us",
"ns",
"sec",
"b",
"kb",
"mb",
"gb",
"tb",
"pb",
"m",
"h",
"d",
}
)
// metricUnits attempts to detect known unit types used as part of a metric name,
// e.g. "foo_bytes_total" or "bar_baz_milligrams".
func metricUnits(m string) (unit, base string, ok bool) {
ss := strings.Split(m, "_")
for _, s := range ss {
if base, found := units[s]; found {
return s, base, true
}
for _, p := range unitPrefixes {
if strings.HasPrefix(s, p) {
if base, found := units[s[len(p):]]; found {
return s, base, true
}
}
}
}
return "", "", false
}