distribution/registry/api/v2/names.go

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package v2
import (
"fmt"
"regexp"
"strings"
)
// TODO(stevvooe): Move these definitions back to an exported package. While
// they are used with v2 definitions, their relevance expands beyond.
// "distribution/names" is a candidate package.
const (
// RepositoryNameComponentMinLength is the minimum number of characters in a
// single repository name slash-delimited component
RepositoryNameComponentMinLength = 2
// RepositoryNameMinComponents is the minimum number of slash-delimited
// components that a repository name must have
RepositoryNameMinComponents = 1
// 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}`)
// TODO(stevvooe): Contribute these exports back to core, so they are shared.
var (
// ErrRepositoryNameComponentShort is returned when a repository name
// contains a component which is shorter than
// RepositoryNameComponentMinLength
ErrRepositoryNameComponentShort = fmt.Errorf("respository name component must be %v or more characters", RepositoryNameComponentMinLength)
// ErrRepositoryNameMissingComponents is returned when a repository name
// contains fewer than RepositoryNameMinComponents components
ErrRepositoryNameMissingComponents = fmt.Errorf("repository name must have at least %v components", RepositoryNameMinComponents)
// 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())
)
// ValidateRespositoryName 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 ValidateRespositoryName(name string) error {
if len(name) > RepositoryNameTotalLengthMax {
return ErrRepositoryNameLong
}
components := strings.Split(name, "/")
if len(components) < RepositoryNameMinComponents {
return ErrRepositoryNameMissingComponents
}
for _, component := range components {
if len(component) < RepositoryNameComponentMinLength {
return ErrRepositoryNameComponentShort
}
if !RepositoryNameComponentAnchoredRegexp.MatchString(component) {
return ErrRepositoryNameComponentInvalid
}
}
return nil
}