distribution/registry/api/v2/names.go
Stephen J Day b54cc5ed47 Allow single character repository names
The main goal of this changeset is to allow repository name components to
consist of a single character. The number of components allowed and the slash
separation requirements have also been clarified.

To go along with this simplification, errant constants and unneeded error types
have been removed.

Signed-off-by: Stephen J Day <stephen.day@docker.com>
2015-07-10 12:10:42 -06:00

84 lines
3.1 KiB
Go

package v2
import (
"fmt"
"regexp"
"strings"
)
// TODO(stevvooe): Move these definitions to the future "reference" package.
// While they are used with v2 definitions, their relevance expands beyond.
const (
// RepositoryNameTotalLengthMax is the maximum total number of characters in
// a repository name
RepositoryNameTotalLengthMax = 255
)
// RepositoryNameComponentRegexp restricts registry path component names to
// start with at least one letter or number, with following parts able to
// be separated by one period, dash or underscore.
var RepositoryNameComponentRegexp = regexp.MustCompile(`[a-z0-9]+(?:[._-][a-z0-9]+)*`)
// RepositoryNameComponentAnchoredRegexp is the version of
// RepositoryNameComponentRegexp which must completely match the content
var RepositoryNameComponentAnchoredRegexp = regexp.MustCompile(`^` + RepositoryNameComponentRegexp.String() + `$`)
// RepositoryNameRegexp builds on RepositoryNameComponentRegexp to allow
// multiple path components, separated by a forward slash.
var RepositoryNameRegexp = regexp.MustCompile(`(?:` + RepositoryNameComponentRegexp.String() + `/)*` + RepositoryNameComponentRegexp.String())
// TagNameRegexp matches valid tag names. From docker/docker:graph/tags.go.
var TagNameRegexp = regexp.MustCompile(`[\w][\w.-]{0,127}`)
// TagNameAnchoredRegexp matches valid tag names, anchored at the start and
// end of the matched string.
var TagNameAnchoredRegexp = regexp.MustCompile("^" + TagNameRegexp.String() + "$")
var (
// ErrRepositoryNameEmpty is returned for empty, invalid repository names.
ErrRepositoryNameEmpty = fmt.Errorf("repository name must have at least one component")
// ErrRepositoryNameLong is returned when a repository name is longer than
// RepositoryNameTotalLengthMax
ErrRepositoryNameLong = fmt.Errorf("repository name must not be more than %v characters", RepositoryNameTotalLengthMax)
// ErrRepositoryNameComponentInvalid is returned when a repository name does
// not match RepositoryNameComponentRegexp
ErrRepositoryNameComponentInvalid = fmt.Errorf("repository name component must match %q", RepositoryNameComponentRegexp.String())
)
// ValidateRepositoryName ensures the repository name is valid for use in the
// registry. This function accepts a superset of what might be accepted by
// docker core or docker hub. If the name does not pass validation, an error,
// describing the conditions, is returned.
//
// Effectively, the name should comply with the following grammar:
//
// alpha-numeric := /[a-z0-9]+/
// separator := /[._-]/
// component := alpha-numeric [separator alpha-numeric]*
// namespace := component ['/' component]*
//
// The result of the production, known as the "namespace", should be limited
// to 255 characters.
func ValidateRepositoryName(name string) error {
if name == "" {
return ErrRepositoryNameEmpty
}
if len(name) > RepositoryNameTotalLengthMax {
return ErrRepositoryNameLong
}
components := strings.Split(name, "/")
for _, component := range components {
if !RepositoryNameComponentAnchoredRegexp.MatchString(component) {
return ErrRepositoryNameComponentInvalid
}
}
return nil
}