karmada/pkg/util/imageparser/lifted.go

44 lines
1.3 KiB
Go

package imageparser
import "regexp"
/*
This code is directly lifted from the distribution codebase as they haven't been exported.
For reference: https://github.com/distribution/distribution/blob/9329f6a62b67d5e06d50dc93997c7705a075fcd9/reference/regexp.go
*/
var (
// match compiles the string to a regular expression.
match = regexp.MustCompile
// TagRegexp matches valid tag names. From docker/docker:graph/tags.go.
TagRegexp = match(`[\w][\w.-]{0,127}`)
// anchoredTagRegexp matches valid tag names, anchored at the start and
// end of the matched string.
anchoredTagRegexp = anchored(TagRegexp)
// DigestRegexp matches valid digests.
DigestRegexp = match(`[A-Za-z][A-Za-z0-9]*(?:[-_+.][A-Za-z][A-Za-z0-9]*)*[:][[:xdigit:]]{32,}`)
// anchoredDigestRegexp matches valid digests, anchored at the start and
// end of the matched string.
anchoredDigestRegexp = anchored(DigestRegexp)
)
// anchored anchors the regular expression by adding start and end delimiters.
func anchored(res ...*regexp.Regexp) *regexp.Regexp {
return match(`^` + expression(res...).String() + `$`)
}
// expression defines a full expression, where each regular expression must
// follow the previous.
func expression(res ...*regexp.Regexp) *regexp.Regexp {
var s string
for _, re := range res {
s += re.String()
}
return match(s)
}