package reference import ( "fmt" "strings" "github.com/docker/distribution/digestset" "github.com/opencontainers/go-digest" ) var ( legacyDefaultDomain = "index.docker.io" defaultDomain = "docker.io" officialRepoName = "library" defaultTag = "latest" ) // normalizedNamed represents a name which has been // normalized and has a familiar form. A familiar name // is what is used in Docker UI. An example normalized // name is "docker.io/library/ubuntu" and corresponding // familiar name of "ubuntu". type normalizedNamed interface { Named Familiar() Named } // ParseNormalizedNamed parses a string into a named reference // transforming a familiar name from Docker UI to a fully // qualified reference. If the value may be an identifier // use ParseAnyReference. func ParseNormalizedNamed(s string) (Named, error) { if ok := anchoredIdentifierRegexp.MatchString(s); ok { return nil, fmt.Errorf("invalid repository name (%s), cannot specify 64-byte hexadecimal strings", s) } domain, remainder := splitDockerDomain(s) var remoteName string if tagSep := strings.IndexRune(remainder, ':'); tagSep > -1 { remoteName = remainder[:tagSep] } else { remoteName = remainder } if strings.ToLower(remoteName) != remoteName { return nil, fmt.Errorf("invalid reference format: repository name (%s) must be lowercase", remoteName) } ref, err := Parse(domain + "/" + remainder) if err != nil { return nil, err } named, isNamed := ref.(Named) if !isNamed { return nil, fmt.Errorf("reference %s has no name", ref.String()) } return named, nil } // ParseDockerRef normalizes the image reference following the docker convention. This is added // mainly for backward compatibility. // The reference returned can only be either tagged or digested. For reference contains both tag // and digest, the function returns digested reference, e.g. docker.io/library/busybox:latest@ // sha256:7cc4b5aefd1d0cadf8d97d4350462ba51c694ebca145b08d7d41b41acc8db5aa will be returned as // docker.io/library/busybox@sha256:7cc4b5aefd1d0cadf8d97d4350462ba51c694ebca145b08d7d41b41acc8db5aa. func ParseDockerRef(ref string) (Named, error) { named, err := ParseNormalizedNamed(ref) if err != nil { return nil, err } if _, ok := named.(NamedTagged); ok { if canonical, ok := named.(Canonical); ok { // The reference is both tagged and digested, only // return digested. newNamed, err := WithName(canonical.Name()) if err != nil { return nil, err } newCanonical, err := WithDigest(newNamed, canonical.Digest()) if err != nil { return nil, err } return newCanonical, nil } } return TagNameOnly(named), nil } // splitDockerDomain splits a repository name to domain and remotename string. // If no valid domain is found, the default domain is used. Repository name // needs to be already validated before. func splitDockerDomain(name string) (domain, remainder string) { i := strings.IndexRune(name, '/') if i == -1 || (!strings.ContainsAny(name[:i], ".:") && name[:i] != "localhost") { domain, remainder = defaultDomain, name } else { domain, remainder = name[:i], name[i+1:] } if domain == legacyDefaultDomain { domain = defaultDomain } if domain == defaultDomain && !strings.ContainsRune(remainder, '/') { remainder = officialRepoName + "/" + remainder } return } // familiarizeName returns a shortened version of the name familiar // to to the Docker UI. Familiar names have the default domain // "docker.io" and "library/" repository prefix removed. // For example, "docker.io/library/redis" will have the familiar // name "redis" and "docker.io/dmcgowan/myapp" will be "dmcgowan/myapp". // Returns a familiarized named only reference. func familiarizeName(named namedRepository) repository { repo := repository{ domain: named.Domain(), path: named.Path(), } if repo.domain == defaultDomain { repo.domain = "" // Handle official repositories which have the pattern "library/" if split := strings.Split(repo.path, "/"); len(split) == 2 && split[0] == officialRepoName { repo.path = split[1] } } return repo } func (r reference) Familiar() Named { return reference{ namedRepository: familiarizeName(r.namedRepository), tag: r.tag, digest: r.digest, } } func (r repository) Familiar() Named { return familiarizeName(r) } func (t taggedReference) Familiar() Named { return taggedReference{ namedRepository: familiarizeName(t.namedRepository), tag: t.tag, } } func (c canonicalReference) Familiar() Named { return canonicalReference{ namedRepository: familiarizeName(c.namedRepository), digest: c.digest, } } // TagNameOnly adds the default tag "latest" to a reference if it only has // a repo name. func TagNameOnly(ref Named) Named { if IsNameOnly(ref) { namedTagged, err := WithTag(ref, defaultTag) if err != nil { // Default tag must be valid, to create a NamedTagged // type with non-validated input the WithTag function // should be used instead panic(err) } return namedTagged } return ref } // ParseAnyReference parses a reference string as a possible identifier, // full digest, or familiar name. func ParseAnyReference(ref string) (Reference, error) { if ok := anchoredIdentifierRegexp.MatchString(ref); ok { return digestReference("sha256:" + ref), nil } if dgst, err := digest.Parse(ref); err == nil { return digestReference(dgst), nil } return ParseNormalizedNamed(ref) } // ParseAnyReferenceWithSet parses a reference string as a possible short // identifier to be matched in a digest set, a full digest, or familiar name. func ParseAnyReferenceWithSet(ref string, ds *digestset.Set) (Reference, error) { if ok := anchoredShortIdentifierRegexp.MatchString(ref); ok { dgst, err := ds.Lookup(ref) if err == nil { return digestReference(dgst), nil } } else { if dgst, err := digest.Parse(ref); err == nil { return digestReference(dgst), nil } } return ParseNormalizedNamed(ref) }