950d34d210
This allows hostnames to contain uppercase characters, matching behavior in Docker versions before 1.10. It does not attempt to canonicalize hostnames into a lowercase format before parsing, since this could lead to corner cases (for example, making Hostname.Domain.Com/ref ambiguous on a daemon which contains references for both hostname.domain.com/ref and Hostname.Domain.Com/ref). Fixes: #1433 Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
125 lines
4.3 KiB
Go
125 lines
4.3 KiB
Go
package reference
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import "regexp"
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var (
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// alphaNumericRegexp defines the alpha numeric atom, typically a
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// component of names. This only allows lower case characters and digits.
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alphaNumericRegexp = match(`[a-z0-9]+`)
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// separatorRegexp defines the separators allowed to be embedded in name
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// components. This allow one period, one or two underscore and multiple
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// dashes.
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separatorRegexp = match(`(?:[._]|__|[-]*)`)
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// nameComponentRegexp restricts registry path component names to start
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// with at least one letter or number, with following parts able to be
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// separated by one period, one or two underscore and multiple dashes.
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nameComponentRegexp = expression(
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alphaNumericRegexp,
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optional(repeated(separatorRegexp, alphaNumericRegexp)))
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// hostnameComponentRegexp restricts the registry hostname component of a
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// repository name to start with a component as defined by hostnameRegexp
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// and followed by an optional port.
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hostnameComponentRegexp = match(`(?:[a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]*[a-zA-Z0-9])`)
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// hostnameRegexp defines the structure of potential hostname components
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// that may be part of image names. This is purposely a subset of what is
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// allowed by DNS to ensure backwards compatibility with Docker image
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// names.
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hostnameRegexp = expression(
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hostnameComponentRegexp,
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optional(repeated(literal(`.`), hostnameComponentRegexp)),
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optional(literal(`:`), match(`[0-9]+`)))
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// TagRegexp matches valid tag names. From docker/docker:graph/tags.go.
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TagRegexp = match(`[\w][\w.-]{0,127}`)
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// anchoredTagRegexp matches valid tag names, anchored at the start and
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// end of the matched string.
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anchoredTagRegexp = anchored(TagRegexp)
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// DigestRegexp matches valid digests.
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DigestRegexp = match(`[A-Za-z][A-Za-z0-9]*(?:[-_+.][A-Za-z][A-Za-z0-9]*)*[:][[:xdigit:]]{32,}`)
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// anchoredDigestRegexp matches valid digests, anchored at the start and
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// end of the matched string.
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anchoredDigestRegexp = anchored(DigestRegexp)
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// NameRegexp is the format for the name component of references. The
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// regexp has capturing groups for the hostname and name part omitting
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// the seperating forward slash from either.
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NameRegexp = expression(
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optional(hostnameRegexp, literal(`/`)),
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nameComponentRegexp,
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optional(repeated(literal(`/`), nameComponentRegexp)))
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// anchoredNameRegexp is used to parse a name value, capturing the
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// hostname and trailing components.
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anchoredNameRegexp = anchored(
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optional(capture(hostnameRegexp), literal(`/`)),
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capture(nameComponentRegexp,
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optional(repeated(literal(`/`), nameComponentRegexp))))
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// ReferenceRegexp is the full supported format of a reference. The regexp
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// is anchored and has capturing groups for name, tag, and digest
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// components.
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ReferenceRegexp = anchored(capture(NameRegexp),
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optional(literal(":"), capture(TagRegexp)),
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optional(literal("@"), capture(DigestRegexp)))
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)
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// match compiles the string to a regular expression.
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var match = regexp.MustCompile
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// literal compiles s into a literal regular expression, escaping any regexp
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// reserved characters.
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func literal(s string) *regexp.Regexp {
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re := match(regexp.QuoteMeta(s))
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if _, complete := re.LiteralPrefix(); !complete {
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panic("must be a literal")
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}
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return re
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}
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// expression defines a full expression, where each regular expression must
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// follow the previous.
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func expression(res ...*regexp.Regexp) *regexp.Regexp {
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var s string
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for _, re := range res {
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s += re.String()
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}
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return match(s)
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}
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// optional wraps the expression in a non-capturing group and makes the
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// production optional.
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func optional(res ...*regexp.Regexp) *regexp.Regexp {
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return match(group(expression(res...)).String() + `?`)
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}
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// repeated wraps the regexp in a non-capturing group to get one or more
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// matches.
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func repeated(res ...*regexp.Regexp) *regexp.Regexp {
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return match(group(expression(res...)).String() + `+`)
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}
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// group wraps the regexp in a non-capturing group.
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func group(res ...*regexp.Regexp) *regexp.Regexp {
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return match(`(?:` + expression(res...).String() + `)`)
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}
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// capture wraps the expression in a capturing group.
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func capture(res ...*regexp.Regexp) *regexp.Regexp {
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return match(`(` + expression(res...).String() + `)`)
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}
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// anchored anchors the regular expression by adding start and end delimiters.
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func anchored(res ...*regexp.Regexp) *regexp.Regexp {
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return match(`^` + expression(res...).String() + `$`)
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}
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