moby--moby/graph/tags/tags.go

37 lines
1004 B
Go

package tags
import (
"fmt"
"regexp"
"github.com/docker/distribution/reference"
)
// DefaultTag defines the default tag used when performing images related actions and no tag string is specified
const DefaultTag = "latest"
var anchoredTagRegexp = regexp.MustCompile(`^` + reference.TagRegexp.String() + `$`)
// ErrTagInvalidFormat is returned if tag is invalid.
type ErrTagInvalidFormat struct {
name string
}
func (e ErrTagInvalidFormat) Error() string {
return fmt.Sprintf("Illegal tag name (%s): only [A-Za-z0-9_.-] are allowed ('.' and '-' are NOT allowed in the initial), minimum 1, maximum 128 in length", e.name)
}
// ValidateTagName validates the name of a tag.
// It returns an error if the given name is an emtpy string.
// If name is not valid, it returns ErrTagInvalidFormat
func ValidateTagName(name string) error {
if name == "" {
return fmt.Errorf("tag name can't be empty")
}
if !anchoredTagRegexp.MatchString(name) {
return ErrTagInvalidFormat{name}
}
return nil
}