Support UTF-8 label matchers: Make functions in compat package public (#3659)

* Make functions in compat package public

This commit makes functions in the compat package public. These
functions are useful for software that builds on top of the
Alertmanager that also need to migrate from classic mode to UTF-8.

Signed-off-by: George Robinson <george.robinson@grafana.com>

* Fix lint

Signed-off-by: George Robinson <george.robinson@grafana.com>

---------

Signed-off-by: George Robinson <george.robinson@grafana.com>

matchers/compat/parse.go

@@ -29,8 +29,8 @@ import (
 
 var (
 	isValidLabelName = isValidClassicLabelName(log.NewNopLogger())
-	parseMatcher     = classicMatcherParser(log.NewNopLogger())
-	parseMatchers    = classicMatchersParser(log.NewNopLogger())
+	parseMatcher     = ClassicMatcherParser(log.NewNopLogger())
+	parseMatchers    = ClassicMatchersParser(log.NewNopLogger())
 )
 
 // IsValidLabelName returns true if the string is a valid label name.
@@ -38,9 +38,9 @@ func IsValidLabelName(name model.LabelName) bool {
 	return isValidLabelName(name)
 }
 
-type matcherParser func(s string) (*labels.Matcher, error)
+type ParseMatcher func(s string) (*labels.Matcher, error)
 
-type matchersParser func(s string) (labels.Matchers, error)
+type ParseMatchers func(s string) (labels.Matchers, error)
 
 // Matcher parses the matcher in the input string. It returns an error
 // if the input is invalid or contains two or more matchers.
@@ -58,41 +58,41 @@ func Matchers(s string) (labels.Matchers, error) {
 func InitFromFlags(l log.Logger, f featurecontrol.Flagger) {
 	if f.ClassicMode() {
 		isValidLabelName = isValidClassicLabelName(l)
-		parseMatcher = classicMatcherParser(l)
-		parseMatchers = classicMatchersParser(l)
+		parseMatcher = ClassicMatcherParser(l)
+		parseMatchers = ClassicMatchersParser(l)
 	} else if f.UTF8StrictMode() {
 		isValidLabelName = isValidUTF8LabelName(l)
-		parseMatcher = utf8MatcherParser(l)
-		parseMatchers = utf8MatchersParser(l)
+		parseMatcher = UTF8MatcherParser(l)
+		parseMatchers = UTF8MatchersParser(l)
 	} else {
 		isValidLabelName = isValidUTF8LabelName(l)
-		parseMatcher = fallbackMatcherParser(l)
-		parseMatchers = fallbackMatchersParser(l)
+		parseMatcher = FallbackMatcherParser(l)
+		parseMatchers = FallbackMatchersParser(l)
 	}
 }
 
-// classicMatcherParser uses the old pkg/labels parser to parse the matcher in
+// ClassicMatcherParser uses the old pkg/labels parser to parse the matcher in
 // the input string.
-func classicMatcherParser(l log.Logger) matcherParser {
+func ClassicMatcherParser(l log.Logger) ParseMatcher {
 	return func(s string) (*labels.Matcher, error) {
 		level.Debug(l).Log("msg", "Parsing with classic matchers parser", "input", s)
 		return labels.ParseMatcher(s)
 	}
 }
 
-// classicMatchersParser uses the old pkg/labels parser to parse zero or more
+// ClassicMatchersParser uses the old pkg/labels parser to parse zero or more
 // matchers in the input string. It returns an error if the input is invalid.
-func classicMatchersParser(l log.Logger) matchersParser {
+func ClassicMatchersParser(l log.Logger) ParseMatchers {
 	return func(s string) (labels.Matchers, error) {
 		level.Debug(l).Log("msg", "Parsing with classic matchers parser", "input", s)
 		return labels.ParseMatchers(s)
 	}
 }
 
-// utf8MatcherParser uses the new matchers/parse parser to parse
+// UTF8MatcherParser uses the new matchers/parse parser to parse
 // the matcher in the input string. If this fails it does not fallback
 // to the old pkg/labels parser.
-func utf8MatcherParser(l log.Logger) matcherParser {
+func UTF8MatcherParser(l log.Logger) ParseMatcher {
 	return func(s string) (*labels.Matcher, error) {
 		level.Debug(l).Log("msg", "Parsing with UTF-8 matchers parser", "input", s)
 		if strings.HasPrefix(s, "{") || strings.HasSuffix(s, "}") {
@@ -102,20 +102,20 @@ func utf8MatcherParser(l log.Logger) matcherParser {
 	}
 }
 
-// utf8MatchersParser uses the new matchers/parse parser to parse
+// UTF8MatchersParser uses the new matchers/parse parser to parse
 // zero or more matchers in the input string. If this fails it
 // does not fallback to the old pkg/labels parser.
-func utf8MatchersParser(l log.Logger) matchersParser {
+func UTF8MatchersParser(l log.Logger) ParseMatchers {
 	return func(s string) (labels.Matchers, error) {
 		level.Debug(l).Log("msg", "Parsing with UTF-8 matchers parser", "input", s)
 		return parse.Matchers(s)
 	}
 }
 
-// fallbackMatcherParser uses the new matchers/parse parser to parse
+// FallbackMatcherParser uses the new matchers/parse parser to parse
 // zero or more matchers in the string. If this fails it falls back to
 // the old pkg/labels parser and emits a warning log line.
-func fallbackMatcherParser(l log.Logger) matcherParser {
+func FallbackMatcherParser(l log.Logger) ParseMatcher {
 	return func(s string) (*labels.Matcher, error) {
 		var (
 			m          *labels.Matcher
@@ -143,10 +143,10 @@ func fallbackMatcherParser(l log.Logger) matcherParser {
 	}
 }
 
-// fallbackMatchersParser uses the new matchers/parse parser to parse the
+// FallbackMatchersParser uses the new matchers/parse parser to parse the
 // matcher in the input string. If this fails it falls back to the old
 // pkg/labels parser and emits a warning log line.
-func fallbackMatchersParser(l log.Logger) matchersParser {
+func FallbackMatchersParser(l log.Logger) ParseMatchers {
 	return func(s string) (labels.Matchers, error) {
 		var (
 			m          []*labels.Matcher

matchers/compat/parse_test.go

@@ -46,7 +46,7 @@ func TestFallbackMatcherParser(t *testing.T) {
 		input: "foo!bar",
 		err:   "bad matcher format: foo!bar",
 	}}
-	f := fallbackMatcherParser(log.NewNopLogger())
+	f := FallbackMatcherParser(log.NewNopLogger())
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
 			matcher, err := f(test.input)
@@ -92,7 +92,7 @@ func TestFallbackMatchersParser(t *testing.T) {
 		input: "{foo!bar}",
 		err:   "bad matcher format: foo!bar",
 	}}
-	f := fallbackMatchersParser(log.NewNopLogger())
+	f := FallbackMatchersParser(log.NewNopLogger())
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
 			matchers, err := f(test.input)