diff --git a/prometheus/testutil/promlint/problem.go b/prometheus/testutil/promlint/problem.go new file mode 100644 index 0000000..9ba4282 --- /dev/null +++ b/prometheus/testutil/promlint/problem.go @@ -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, + } +} diff --git a/prometheus/testutil/promlint/promlint.go b/prometheus/testutil/promlint/promlint.go index c8864b6..dd29ccc 100644 --- a/prometheus/testutil/promlint/promlint.go +++ b/prometheus/testutil/promlint/promlint.go @@ -16,15 +16,11 @@ package promlint import ( "errors" - "fmt" "io" - "regexp" "sort" - "strings" - - "github.com/prometheus/common/expfmt" dto "github.com/prometheus/client_model/go" + "github.com/prometheus/common/expfmt" ) // A Linter is a Prometheus metrics linter. It identifies issues with metric @@ -37,23 +33,8 @@ type Linter struct { // of them. r io.Reader mfs []*dto.MetricFamily -} -// 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, - } + customValidations []Validation } // 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 // issues found in the metrics stream. The slice is sorted by metric name // and issue description. @@ -91,11 +80,11 @@ func (l *Linter) Lint() ([]Problem, error) { return nil, err } - problems = append(problems, lint(mf)...) + problems = append(problems, l.lint(mf)...) } } for _, mf := range l.mfs { - problems = append(problems, lint(mf)...) + problems = append(problems, l.lint(mf)...) } // Ensure deterministic output. @@ -110,276 +99,25 @@ func (l *Linter) Lint() ([]Problem, error) { } // lint is the entry point for linting a single metric. -func lint(mf *dto.MetricFamily) []Problem { - fns := []func(mf *dto.MetricFamily) []Problem{ - lintHelp, - lintMetricUnits, - lintCounter, - lintHistogramSummaryReserved, - lintMetricTypeInName, - lintReservedChars, - lintCamelCase, - lintUnitAbbreviations, +func (l *Linter) lint(mf *dto.MetricFamily) []Problem { + var problems []Problem + + for _, fn := range defaultValidations { + errs := fn(mf) + for _, err := range errs { + problems = append(problems, newProblem(mf, err.Error())) + } } - var problems []Problem - for _, fn := range fns { - problems = append(problems, fn(mf)...) + if l.customValidations != nil { + for _, fn := range l.customValidations { + errs := fn(mf) + for _, err := range errs { + problems = append(problems, newProblem(mf, err.Error())) + } + } } // TODO(mdlayher): lint rules for specific metrics types. 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", - } -) diff --git a/prometheus/testutil/promlint/promlint_test.go b/prometheus/testutil/promlint/promlint_test.go index 70b1908..3617ed8 100644 --- a/prometheus/testutil/promlint/promlint_test.go +++ b/prometheus/testutil/promlint/promlint_test.go @@ -19,6 +19,8 @@ import ( "strings" "testing" + dto "github.com/prometheus/client_model/go" + "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) + }) +} diff --git a/prometheus/testutil/promlint/validation.go b/prometheus/testutil/promlint/validation.go new file mode 100644 index 0000000..f52ad9e --- /dev/null +++ b/prometheus/testutil/promlint/validation.go @@ -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, +} diff --git a/prometheus/testutil/promlint/validations/counter_validations.go b/prometheus/testutil/promlint/validations/counter_validations.go new file mode 100644 index 0000000..f2c2c39 --- /dev/null +++ b/prometheus/testutil/promlint/validations/counter_validations.go @@ -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 +} diff --git a/prometheus/testutil/promlint/validations/generic_name_validations.go b/prometheus/testutil/promlint/validations/generic_name_validations.go new file mode 100644 index 0000000..bc8dbd1 --- /dev/null +++ b/prometheus/testutil/promlint/validations/generic_name_validations.go @@ -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 +} diff --git a/prometheus/testutil/promlint/validations/help_validations.go b/prometheus/testutil/promlint/validations/help_validations.go new file mode 100644 index 0000000..1df2944 --- /dev/null +++ b/prometheus/testutil/promlint/validations/help_validations.go @@ -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 +} diff --git a/prometheus/testutil/promlint/validations/histogram_validations.go b/prometheus/testutil/promlint/validations/histogram_validations.go new file mode 100644 index 0000000..6564bdf --- /dev/null +++ b/prometheus/testutil/promlint/validations/histogram_validations.go @@ -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 +} diff --git a/prometheus/testutil/promlint/validations/units.go b/prometheus/testutil/promlint/validations/units.go new file mode 100644 index 0000000..967977d --- /dev/null +++ b/prometheus/testutil/promlint/validations/units.go @@ -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 +}