Move old parser into matcher package

This is the first of two commits that removes matchers from the
deprecated pkg/labels package and into the new matcher package.
It moves the old regex parser that is known as classic mode
into a package called oldparse. This package will be deleted
in future when classic mode is removed.

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

matcher/compat/parse.go

@@ -24,6 +24,7 @@ import (
  "github.com/prometheus/common/model"
 
  "github.com/prometheus/alertmanager/featurecontrol"
+ "github.com/prometheus/alertmanager/matcher/oldparse"
  "github.com/prometheus/alertmanager/matcher/parse"
  "github.com/prometheus/alertmanager/pkg/labels"
 )
@@ -77,7 +78,7 @@ func InitFromFlags(l log.Logger, f featurecontrol.Flagger) {
 func ClassicMatcherParser(l log.Logger) ParseMatcher {
  return func(input, origin string) (matcher *labels.Matcher, err error) {
  level.Debug(l).Log("msg", "Parsing with classic matchers parser", "input", input, "origin", origin)
- return labels.ParseMatcher(input)
+ return oldparse.ParseMatcher(input)
  }
 }
 
@@ -86,7 +87,7 @@ func ClassicMatcherParser(l log.Logger) ParseMatcher {
 func ClassicMatchersParser(l log.Logger) ParseMatchers {
  return func(input, origin string) (matchers labels.Matchers, err error) {
  level.Debug(l).Log("msg", "Parsing with classic matchers parser", "input", input, "origin", origin)
- return labels.ParseMatchers(input)
+ return oldparse.ParseMatchers(input)
  }
 }
 
@@ -124,7 +125,7 @@ func FallbackMatcherParser(l log.Logger) ParseMatcher {
  // Parse the input in both parsers to look for disagreement and incompatible
  // inputs.
  nMatcher, nErr := parse.Matcher(input)
- cMatcher, cErr := labels.ParseMatcher(input)
+ cMatcher, cErr := oldparse.ParseMatcher(input)
  if nErr != nil {
  // If the input is invalid in both parsers, return the error.
  if cErr != nil {
@@ -155,7 +156,7 @@ func FallbackMatchersParser(l log.Logger) ParseMatchers {
  // Parse the input in both parsers to look for disagreement and incompatible
  // inputs.
  nMatchers, nErr := parse.Matchers(input)
- cMatchers, cErr := labels.ParseMatchers(input)
+ cMatchers, cErr := oldparse.ParseMatchers(input)
  if nErr != nil {
  // If the input is invalid in both parsers, return the error.
  if cErr != nil {

pkg/labels/parse.go → matcher/oldparse/parse.go

@@ -11,24 +11,26 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package labels
+package oldparse
 
 import (
  "fmt"
  "regexp"
  "strings"
  "unicode/utf8"
+
+ "github.com/prometheus/alertmanager/pkg/labels"
 )
 
 var (
  // '=~' has to come before '=' because otherwise only the '='
  // will be consumed, and the '~' will be part of the 3rd token.
  re = regexp.MustCompile(`^\s*([a-zA-Z_:][a-zA-Z0-9_:]*)\s*(=~|=|!=|!~)\s*((?s).*?)\s*$`)
- typeMap = map[string]MatchType{
- "=": MatchEqual,
- "!=": MatchNotEqual,
- "=~": MatchRegexp,
- "!~": MatchNotRegexp,
+ typeMap = map[string]labels.MatchType{
+ "=": labels.MatchEqual,
+ "!=": labels.MatchNotEqual,
+ "=~": labels.MatchRegexp,
+ "!~": labels.MatchNotRegexp,
  }
 )
 
@@ -52,8 +54,8 @@ var (
 // statuscode=~"5.."
 //
 // See ParseMatcher for details on how an individual Matcher is parsed.
-func ParseMatchers(s string) ([]*Matcher, error) {
- matchers := []*Matcher{}
+func ParseMatchers(s string) ([]*labels.Matcher, error) {
+ matchers := []*labels.Matcher{}
  s = strings.TrimPrefix(s, "{")
  s = strings.TrimSuffix(s, "}")
 
@@ -114,7 +116,7 @@ func ParseMatchers(s string) ([]*Matcher, error) {
 // character). However, literal line feed characters are tolerated, as are
 // single '\' characters not followed by '\', 'n', or '"'. They act as a literal
 // backslash in that case.
-func ParseMatcher(s string) (_ *Matcher, err error) {
+func ParseMatcher(s string) (_ *labels.Matcher, err error) {
  ms := re.FindStringSubmatch(s)
  if len(ms) == 0 {
  return nil, fmt.Errorf("bad matcher format: %s", s)
@@ -174,5 +176,5 @@ func ParseMatcher(s string) (_ *Matcher, err error) {
  return nil, fmt.Errorf("matcher value contains unescaped double quote: %s", ms[3])
  }
 
- return NewMatcher(typeMap[ms[2]], ms[1], value.String())
+ return labels.NewMatcher(typeMap[ms[2]], ms[1], value.String())
 }