Merge pull request #1239 from stevvooe/refactor-reference-grammar
reference: refactor grammar and regular expressionsmaster
Stephen Day
commit
7a584f21b8
|
|
@ -4,22 +4,16 @@
|
|||
// Grammar
|
||||
//
|
||||
// reference := repository [ ":" tag ] [ "@" digest ]
|
||||
// name := [hostname '/'] component ['/' component]*
|
||||
// hostname := hostcomponent ['.' hostcomponent]* [':' port-number]
|
||||
// hostcomponent := /([a-z0-9]|[a-z0-9][a-z0-9-]*[a-z0-9])/
|
||||
// port-number := /[0-9]+/
|
||||
// component := alpha-numeric [separator alpha-numeric]*
|
||||
// alpha-numeric := /[a-z0-9]+/
|
||||
// separator := /[_.]|__|[-]*/
|
||||
//
|
||||
// // repository.go
|
||||
// repository := hostname ['/' component]+
|
||||
// hostname := hostcomponent [':' port-number]
|
||||
// component := subcomponent [separator subcomponent]*
|
||||
// subcomponent := alpha-numeric ['-'* alpha-numeric]*
|
||||
// hostcomponent := [hostpart '.']* hostpart
|
||||
// alpha-numeric := /[a-z0-9]+/
|
||||
// separator := /([_.]|__)/
|
||||
// port-number := /[0-9]+/
|
||||
// hostpart := /([a-z0-9]|[a-z0-9][a-z0-9-]*[a-z0-9])/
|
||||
//
|
||||
// // tag.go
|
||||
// tag := /[\w][\w.-]{0,127}/
|
||||
//
|
||||
// // from the digest package
|
||||
// digest := digest-algorithm ":" digest-hex
|
||||
// digest-algorithm := digest-algorithm-component [ digest-algorithm-separator digest-algorithm-component ]
|
||||
// digest-algorithm-separator := /[+.-_]/
|
||||
|
|
|
|||
|
|
@ -3,47 +3,122 @@ package reference
|
|||
import "regexp"
|
||||
|
||||
var (
|
||||
// nameSubComponentRegexp defines the part of the name which must be
|
||||
// begin and end with an alphanumeric character. These characters can
|
||||
// be separated by any number of dashes.
|
||||
nameSubComponentRegexp = regexp.MustCompile(`[a-z0-9]+(?:[-]+[a-z0-9]+)*`)
|
||||
// alphaNumericRegexp defines the alpha numeric atom, typically a
|
||||
// component of names. This only allows lower case characters and digits.
|
||||
alphaNumericRegexp = match(`[a-z0-9]+`)
|
||||
|
||||
// nameComponentRegexp restricts registry path component names to
|
||||
// start with at least one letter or number, with following parts able to
|
||||
// be separated by one period, underscore or double underscore.
|
||||
nameComponentRegexp = regexp.MustCompile(nameSubComponentRegexp.String() + `(?:(?:[._]|__)` + nameSubComponentRegexp.String() + `)*`)
|
||||
// separatorRegexp defines the separators allowed to be embedded in name
|
||||
// components. This allow one period, one or two underscore and multiple
|
||||
// dashes.
|
||||
separatorRegexp = match(`(?:[._]|__|[-]*)`)
|
||||
|
||||
nameRegexp = regexp.MustCompile(`(?:` + nameComponentRegexp.String() + `/)*` + nameComponentRegexp.String())
|
||||
// nameComponentRegexp restricts registry path component names to start
|
||||
// with at least one letter or number, with following parts able to be
|
||||
// separated by one period, one or two underscore and multiple dashes.
|
||||
nameComponentRegexp = expression(
|
||||
alphaNumericRegexp,
|
||||
optional(repeated(separatorRegexp, alphaNumericRegexp)))
|
||||
|
||||
hostnameComponentRegexp = regexp.MustCompile(`(?:[a-z0-9]|[a-z0-9][a-z0-9-]*[a-z0-9])`)
|
||||
// hostnameComponentRegexp restricts the registry hostname component of a
|
||||
// repository name to start with a component as defined by hostnameRegexp
|
||||
// and followed by an optional port.
|
||||
hostnameComponentRegexp = match(`(?:[a-z0-9]|[a-z0-9][a-z0-9-]*[a-z0-9])`)
|
||||
|
||||
// hostnameComponentRegexp restricts the registry hostname component of a repository name to
|
||||
// start with a component as defined by hostnameRegexp and followed by an optional port.
|
||||
hostnameRegexp = regexp.MustCompile(`(?:` + hostnameComponentRegexp.String() + `\.)*` + hostnameComponentRegexp.String() + `(?::[0-9]+)?`)
|
||||
// hostnameRegexp defines the structure of potential hostname components
|
||||
// that may be part of image names. This is purposely a subset of what is
|
||||
// allowed by DNS to ensure backwards compatibility with Docker image
|
||||
// names.
|
||||
hostnameRegexp = expression(
|
||||
hostnameComponentRegexp,
|
||||
optional(repeated(literal(`.`), hostnameComponentRegexp)),
|
||||
optional(literal(`:`), match(`[0-9]+`)))
|
||||
|
||||
// TagRegexp matches valid tag names. From docker/docker:graph/tags.go.
|
||||
TagRegexp = regexp.MustCompile(`[\w][\w.-]{0,127}`)
|
||||
TagRegexp = match(`[\w][\w.-]{0,127}`)
|
||||
|
||||
// anchoredTagRegexp matches valid tag names, anchored at the start and
|
||||
// end of the matched string.
|
||||
anchoredTagRegexp = regexp.MustCompile(`^` + TagRegexp.String() + `$`)
|
||||
anchoredTagRegexp = anchored(TagRegexp)
|
||||
|
||||
// DigestRegexp matches valid digests.
|
||||
DigestRegexp = regexp.MustCompile(`[A-Za-z][A-Za-z0-9]*(?:[-_+.][A-Za-z][A-Za-z0-9]*)*[:][[:xdigit:]]{32,}`)
|
||||
DigestRegexp = match(`[A-Za-z][A-Za-z0-9]*(?:[-_+.][A-Za-z][A-Za-z0-9]*)*[:][[:xdigit:]]{32,}`)
|
||||
|
||||
// anchoredDigestRegexp matches valid digests, anchored at the start and
|
||||
// end of the matched string.
|
||||
anchoredDigestRegexp = regexp.MustCompile(`^` + DigestRegexp.String() + `$`)
|
||||
anchoredDigestRegexp = anchored(DigestRegexp)
|
||||
|
||||
// NameRegexp is the format for the name component of references. The
|
||||
// regexp has capturing groups for the hostname and name part omitting
|
||||
// the seperating forward slash from either.
|
||||
NameRegexp = regexp.MustCompile(`(?:` + hostnameRegexp.String() + `/)?` + nameRegexp.String())
|
||||
NameRegexp = expression(
|
||||
optional(hostnameRegexp, literal(`/`)),
|
||||
nameComponentRegexp,
|
||||
optional(repeated(literal(`/`), nameComponentRegexp)))
|
||||
|
||||
// ReferenceRegexp is the full supported format of a reference. The
|
||||
// regexp has capturing groups for name, tag, and digest components.
|
||||
ReferenceRegexp = regexp.MustCompile(`^((?:` + hostnameRegexp.String() + `/)?` + nameRegexp.String() + `)(?:[:](` + TagRegexp.String() + `))?(?:[@](` + DigestRegexp.String() + `))?$`)
|
||||
// anchoredNameRegexp is used to parse a name value, capturing the
|
||||
// hostname and trailing components.
|
||||
anchoredNameRegexp = anchored(
|
||||
optional(capture(hostnameRegexp), literal(`/`)),
|
||||
capture(nameComponentRegexp,
|
||||
optional(repeated(literal(`/`), nameComponentRegexp))))
|
||||
|
||||
// anchoredNameRegexp is used to parse a name value, capturing hostname
|
||||
anchoredNameRegexp = regexp.MustCompile(`^(?:(` + hostnameRegexp.String() + `)/)?(` + nameRegexp.String() + `)$`)
|
||||
// ReferenceRegexp is the full supported format of a reference. The regexp
|
||||
// is anchored and has capturing groups for name, tag, and digest
|
||||
// components.
|
||||
ReferenceRegexp = anchored(capture(NameRegexp),
|
||||
optional(literal(":"), capture(TagRegexp)),
|
||||
optional(literal("@"), capture(DigestRegexp)))
|
||||
)
|
||||
|
||||
// match compiles the string to a regular expression.
|
||||
var match = regexp.MustCompile
|
||||
|
||||
// literal compiles s into a literal regular expression, escaping any regexp
|
||||
// reserved characters.
|
||||
func literal(s string) *regexp.Regexp {
|
||||
re := match(regexp.QuoteMeta(s))
|
||||
|
||||
if _, complete := re.LiteralPrefix(); !complete {
|
||||
panic("must be a literal")
|
||||
}
|
||||
|
||||
return re
|
||||
}
|
||||
|
||||
// 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)
|
||||
}
|
||||
|
||||
// optional wraps the expression in a non-capturing group and makes the
|
||||
// production optional.
|
||||
func optional(res ...*regexp.Regexp) *regexp.Regexp {
|
||||
return match(group(expression(res...)).String() + `?`)
|
||||
}
|
||||
|
||||
// repeated wraps the regexp in a non-capturing group to get one or more
|
||||
// matches.
|
||||
func repeated(res ...*regexp.Regexp) *regexp.Regexp {
|
||||
return match(group(expression(res...)).String() + `+`)
|
||||
}
|
||||
|
||||
// group wraps the regexp in a non-capturing group.
|
||||
func group(res ...*regexp.Regexp) *regexp.Regexp {
|
||||
return match(`(?:` + expression(res...).String() + `)`)
|
||||
}
|
||||
|
||||
// capture wraps the expression in a capturing group.
|
||||
func capture(res ...*regexp.Regexp) *regexp.Regexp {
|
||||
return match(`(` + expression(res...).String() + `)`)
|
||||
}
|
||||
|
||||
// anchored anchors the regular expression by adding start and end delimiters.
|
||||
func anchored(res ...*regexp.Regexp) *regexp.Regexp {
|
||||
return match(`^` + expression(res...).String() + `$`)
|
||||
}
|
||||
|
|
|
|||
|
|
@ -119,6 +119,11 @@ func TestHostRegexp(t *testing.T) {
|
|||
}
|
||||
|
||||
func TestFullNameRegexp(t *testing.T) {
|
||||
if anchoredNameRegexp.NumSubexp() != 2 {
|
||||
t.Fatalf("anchored name regexp should have two submatches: %v, %v != 2",
|
||||
anchoredNameRegexp, anchoredNameRegexp.NumSubexp())
|
||||
}
|
||||
|
||||
testcases := []regexpMatch{
|
||||
{
|
||||
input: "",
|
||||
|
|
@ -401,6 +406,11 @@ func TestFullNameRegexp(t *testing.T) {
|
|||
}
|
||||
|
||||
func TestReferenceRegexp(t *testing.T) {
|
||||
if ReferenceRegexp.NumSubexp() != 3 {
|
||||
t.Fatalf("anchored name regexp should have three submatches: %v, %v != 3",
|
||||
ReferenceRegexp, ReferenceRegexp.NumSubexp())
|
||||
}
|
||||
|
||||
testcases := []regexpMatch{
|
||||
{
|
||||
input: "registry.com:8080/myapp:tag",
|
||||
|
|
|
|||
Loading…
Reference in New Issue