From 901bcb2231466229d27aee8d38a6e2fcdc95015e Mon Sep 17 00:00:00 2001 From: Michael Crosby Date: Mon, 7 Oct 2019 13:38:12 -0400 Subject: [PATCH] Add distribution subpkgs to core Ref: #3554 Signed-off-by: Michael Crosby --- images/archive/reference.go | 2 +- reference/docker/reference.go | 797 ++++++++++++++++++++++++++++++++ remotes/docker/errcode.go | 283 ++++++++++++ remotes/docker/errdesc.go | 154 ++++++ remotes/docker/fetcher.go | 3 +- remotes/docker/fetcher_test.go | 5 +- remotes/docker/resolver_test.go | 2 +- 7 files changed, 1239 insertions(+), 7 deletions(-) create mode 100644 reference/docker/reference.go create mode 100644 remotes/docker/errcode.go create mode 100644 remotes/docker/errdesc.go diff --git a/images/archive/reference.go b/images/archive/reference.go index cd63517e5..ce9fe98f9 100644 --- a/images/archive/reference.go +++ b/images/archive/reference.go @@ -20,7 +20,7 @@ import ( "strings" "github.com/containerd/containerd/reference" - distref "github.com/docker/distribution/reference" + distref "github.com/containerd/containerd/reference/docker" "github.com/opencontainers/go-digest" "github.com/pkg/errors" ) diff --git a/reference/docker/reference.go b/reference/docker/reference.go new file mode 100644 index 000000000..0998639b0 --- /dev/null +++ b/reference/docker/reference.go @@ -0,0 +1,797 @@ +/* + Copyright The containerd Authors. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +// Package docker provides a general type to represent any way of referencing images within the registry. +// Its main purpose is to abstract tags and digests (content-addressable hash). +// +// Grammar +// +// reference := name [ ":" tag ] [ "@" digest ] +// name := [domain '/'] path-component ['/' path-component]* +// domain := domain-component ['.' domain-component]* [':' port-number] +// domain-component := /([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]*[a-zA-Z0-9])/ +// port-number := /[0-9]+/ +// path-component := alpha-numeric [separator alpha-numeric]* +// alpha-numeric := /[a-z0-9]+/ +// separator := /[_.]|__|[-]*/ +// +// tag := /[\w][\w.-]{0,127}/ +// +// digest := digest-algorithm ":" digest-hex +// digest-algorithm := digest-algorithm-component [ digest-algorithm-separator digest-algorithm-component ]* +// digest-algorithm-separator := /[+.-_]/ +// digest-algorithm-component := /[A-Za-z][A-Za-z0-9]*/ +// digest-hex := /[0-9a-fA-F]{32,}/ ; At least 128 bit digest value +// +// identifier := /[a-f0-9]{64}/ +// short-identifier := /[a-f0-9]{6,64}/ +package docker + +import ( + "errors" + "fmt" + "path" + "regexp" + "strings" + + "github.com/opencontainers/go-digest" +) + +const ( + // NameTotalLengthMax is the maximum total number of characters in a repository name. + NameTotalLengthMax = 255 +) + +var ( + // ErrReferenceInvalidFormat represents an error while trying to parse a string as a reference. + ErrReferenceInvalidFormat = errors.New("invalid reference format") + + // ErrTagInvalidFormat represents an error while trying to parse a string as a tag. + ErrTagInvalidFormat = errors.New("invalid tag format") + + // ErrDigestInvalidFormat represents an error while trying to parse a string as a tag. + ErrDigestInvalidFormat = errors.New("invalid digest format") + + // ErrNameContainsUppercase is returned for invalid repository names that contain uppercase characters. + ErrNameContainsUppercase = errors.New("repository name must be lowercase") + + // ErrNameEmpty is returned for empty, invalid repository names. + ErrNameEmpty = errors.New("repository name must have at least one component") + + // ErrNameTooLong is returned when a repository name is longer than NameTotalLengthMax. + ErrNameTooLong = fmt.Errorf("repository name must not be more than %v characters", NameTotalLengthMax) + + // ErrNameNotCanonical is returned when a name is not canonical. + ErrNameNotCanonical = errors.New("repository name must be canonical") +) + +// Reference is an opaque object reference identifier that may include +// modifiers such as a hostname, name, tag, and digest. +type Reference interface { + // String returns the full reference + String() string +} + +// Field provides a wrapper type for resolving correct reference types when +// working with encoding. +type Field struct { + reference Reference +} + +// AsField wraps a reference in a Field for encoding. +func AsField(reference Reference) Field { + return Field{reference} +} + +// Reference unwraps the reference type from the field to +// return the Reference object. This object should be +// of the appropriate type to further check for different +// reference types. +func (f Field) Reference() Reference { + return f.reference +} + +// MarshalText serializes the field to byte text which +// is the string of the reference. +func (f Field) MarshalText() (p []byte, err error) { + return []byte(f.reference.String()), nil +} + +// UnmarshalText parses text bytes by invoking the +// reference parser to ensure the appropriately +// typed reference object is wrapped by field. +func (f *Field) UnmarshalText(p []byte) error { + r, err := Parse(string(p)) + if err != nil { + return err + } + + f.reference = r + return nil +} + +// Named is an object with a full name +type Named interface { + Reference + Name() string +} + +// Tagged is an object which has a tag +type Tagged interface { + Reference + Tag() string +} + +// NamedTagged is an object including a name and tag. +type NamedTagged interface { + Named + Tag() string +} + +// Digested is an object which has a digest +// in which it can be referenced by +type Digested interface { + Reference + Digest() digest.Digest +} + +// Canonical reference is an object with a fully unique +// name including a name with domain and digest +type Canonical interface { + Named + Digest() digest.Digest +} + +// namedRepository is a reference to a repository with a name. +// A namedRepository has both domain and path components. +type namedRepository interface { + Named + Domain() string + Path() string +} + +// Domain returns the domain part of the Named reference +func Domain(named Named) string { + if r, ok := named.(namedRepository); ok { + return r.Domain() + } + domain, _ := splitDomain(named.Name()) + return domain +} + +// Path returns the name without the domain part of the Named reference +func Path(named Named) (name string) { + if r, ok := named.(namedRepository); ok { + return r.Path() + } + _, path := splitDomain(named.Name()) + return path +} + +func splitDomain(name string) (string, string) { + match := anchoredNameRegexp.FindStringSubmatch(name) + if len(match) != 3 { + return "", name + } + return match[1], match[2] +} + +// SplitHostname splits a named reference into a +// hostname and name string. If no valid hostname is +// found, the hostname is empty and the full value +// is returned as name +// DEPRECATED: Use Domain or Path +func SplitHostname(named Named) (string, string) { + if r, ok := named.(namedRepository); ok { + return r.Domain(), r.Path() + } + return splitDomain(named.Name()) +} + +// Parse parses s and returns a syntactically valid Reference. +// If an error was encountered it is returned, along with a nil Reference. +// NOTE: Parse will not handle short digests. +func Parse(s string) (Reference, error) { + matches := ReferenceRegexp.FindStringSubmatch(s) + if matches == nil { + if s == "" { + return nil, ErrNameEmpty + } + if ReferenceRegexp.FindStringSubmatch(strings.ToLower(s)) != nil { + return nil, ErrNameContainsUppercase + } + return nil, ErrReferenceInvalidFormat + } + + if len(matches[1]) > NameTotalLengthMax { + return nil, ErrNameTooLong + } + + var repo repository + + nameMatch := anchoredNameRegexp.FindStringSubmatch(matches[1]) + if len(nameMatch) == 3 { + repo.domain = nameMatch[1] + repo.path = nameMatch[2] + } else { + repo.domain = "" + repo.path = matches[1] + } + + ref := reference{ + namedRepository: repo, + tag: matches[2], + } + if matches[3] != "" { + var err error + ref.digest, err = digest.Parse(matches[3]) + if err != nil { + return nil, err + } + } + + r := getBestReferenceType(ref) + if r == nil { + return nil, ErrNameEmpty + } + + return r, nil +} + +// ParseNamed parses s and returns a syntactically valid reference implementing +// the Named interface. The reference must have a name and be in the canonical +// form, otherwise an error is returned. +// If an error was encountered it is returned, along with a nil Reference. +// NOTE: ParseNamed will not handle short digests. +func ParseNamed(s string) (Named, error) { + named, err := ParseNormalizedNamed(s) + if err != nil { + return nil, err + } + if named.String() != s { + return nil, ErrNameNotCanonical + } + return named, nil +} + +// WithName returns a named object representing the given string. If the input +// is invalid ErrReferenceInvalidFormat will be returned. +func WithName(name string) (Named, error) { + if len(name) > NameTotalLengthMax { + return nil, ErrNameTooLong + } + + match := anchoredNameRegexp.FindStringSubmatch(name) + if match == nil || len(match) != 3 { + return nil, ErrReferenceInvalidFormat + } + return repository{ + domain: match[1], + path: match[2], + }, nil +} + +// WithTag combines the name from "name" and the tag from "tag" to form a +// reference incorporating both the name and the tag. +func WithTag(name Named, tag string) (NamedTagged, error) { + if !anchoredTagRegexp.MatchString(tag) { + return nil, ErrTagInvalidFormat + } + var repo repository + if r, ok := name.(namedRepository); ok { + repo.domain = r.Domain() + repo.path = r.Path() + } else { + repo.path = name.Name() + } + if canonical, ok := name.(Canonical); ok { + return reference{ + namedRepository: repo, + tag: tag, + digest: canonical.Digest(), + }, nil + } + return taggedReference{ + namedRepository: repo, + tag: tag, + }, nil +} + +// WithDigest combines the name from "name" and the digest from "digest" to form +// a reference incorporating both the name and the digest. +func WithDigest(name Named, digest digest.Digest) (Canonical, error) { + if !anchoredDigestRegexp.MatchString(digest.String()) { + return nil, ErrDigestInvalidFormat + } + var repo repository + if r, ok := name.(namedRepository); ok { + repo.domain = r.Domain() + repo.path = r.Path() + } else { + repo.path = name.Name() + } + if tagged, ok := name.(Tagged); ok { + return reference{ + namedRepository: repo, + tag: tagged.Tag(), + digest: digest, + }, nil + } + return canonicalReference{ + namedRepository: repo, + digest: digest, + }, nil +} + +// TrimNamed removes any tag or digest from the named reference. +func TrimNamed(ref Named) Named { + domain, path := SplitHostname(ref) + return repository{ + domain: domain, + path: path, + } +} + +func getBestReferenceType(ref reference) Reference { + if ref.Name() == "" { + // Allow digest only references + if ref.digest != "" { + return digestReference(ref.digest) + } + return nil + } + if ref.tag == "" { + if ref.digest != "" { + return canonicalReference{ + namedRepository: ref.namedRepository, + digest: ref.digest, + } + } + return ref.namedRepository + } + if ref.digest == "" { + return taggedReference{ + namedRepository: ref.namedRepository, + tag: ref.tag, + } + } + + return ref +} + +type reference struct { + namedRepository + tag string + digest digest.Digest +} + +func (r reference) String() string { + return r.Name() + ":" + r.tag + "@" + r.digest.String() +} + +func (r reference) Tag() string { + return r.tag +} + +func (r reference) Digest() digest.Digest { + return r.digest +} + +type repository struct { + domain string + path string +} + +func (r repository) String() string { + return r.Name() +} + +func (r repository) Name() string { + if r.domain == "" { + return r.path + } + return r.domain + "/" + r.path +} + +func (r repository) Domain() string { + return r.domain +} + +func (r repository) Path() string { + return r.path +} + +type digestReference digest.Digest + +func (d digestReference) String() string { + return digest.Digest(d).String() +} + +func (d digestReference) Digest() digest.Digest { + return digest.Digest(d) +} + +type taggedReference struct { + namedRepository + tag string +} + +func (t taggedReference) String() string { + return t.Name() + ":" + t.tag +} + +func (t taggedReference) Tag() string { + return t.tag +} + +type canonicalReference struct { + namedRepository + digest digest.Digest +} + +func (c canonicalReference) String() string { + return c.Name() + "@" + c.digest.String() +} + +func (c canonicalReference) Digest() digest.Digest { + return c.digest +} + +var ( + // alphaNumericRegexp defines the alpha numeric atom, typically a + // component of names. This only allows lower case characters and digits. + alphaNumericRegexp = match(`[a-z0-9]+`) + + // separatorRegexp defines the separators allowed to be embedded in name + // components. This allow one period, one or two underscore and multiple + // dashes. + separatorRegexp = match(`(?:[._]|__|[-]*)`) + + // 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))) + + // domainComponentRegexp restricts the registry domain component of a + // repository name to start with a component as defined by DomainRegexp + // and followed by an optional port. + domainComponentRegexp = match(`(?:[a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]*[a-zA-Z0-9])`) + + // DomainRegexp defines the structure of potential domain 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. + DomainRegexp = expression( + domainComponentRegexp, + optional(repeated(literal(`.`), domainComponentRegexp)), + optional(literal(`:`), match(`[0-9]+`))) + + // TagRegexp matches valid tag names. From docker/docker:graph/tags.go. + TagRegexp = match(`[\w][\w.-]{0,127}`) + + // anchoredTagRegexp matches valid tag names, anchored at the start and + // end of the matched string. + anchoredTagRegexp = anchored(TagRegexp) + + // DigestRegexp matches valid digests. + 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 = anchored(DigestRegexp) + + // NameRegexp is the format for the name component of references. The + // regexp has capturing groups for the domain and name part omitting + // the separating forward slash from either. + NameRegexp = expression( + optional(DomainRegexp, literal(`/`)), + nameComponentRegexp, + optional(repeated(literal(`/`), nameComponentRegexp))) + + // anchoredNameRegexp is used to parse a name value, capturing the + // domain and trailing components. + anchoredNameRegexp = anchored( + optional(capture(DomainRegexp), literal(`/`)), + capture(nameComponentRegexp, + optional(repeated(literal(`/`), nameComponentRegexp)))) + + // 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))) + + // IdentifierRegexp is the format for string identifier used as a + // content addressable identifier using sha256. These identifiers + // are like digests without the algorithm, since sha256 is used. + IdentifierRegexp = match(`([a-f0-9]{64})`) + + // ShortIdentifierRegexp is the format used to represent a prefix + // of an identifier. A prefix may be used to match a sha256 identifier + // within a list of trusted identifiers. + ShortIdentifierRegexp = match(`([a-f0-9]{6,64})`) + + // anchoredIdentifierRegexp is used to check or match an + // identifier value, anchored at start and end of string. + anchoredIdentifierRegexp = anchored(IdentifierRegexp) +) + +// 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() + `$`) +} + +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, errors.New("invalid reference format: repository name must be lowercase") + } + + 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) +} + +// IsNameOnly returns true if reference only contains a repo name. +func IsNameOnly(ref Named) bool { + if _, ok := ref.(NamedTagged); ok { + return false + } + if _, ok := ref.(Canonical); ok { + return false + } + return true +} + +// FamiliarName returns the familiar name string +// for the given named, familiarizing if needed. +func FamiliarName(ref Named) string { + if nn, ok := ref.(normalizedNamed); ok { + return nn.Familiar().Name() + } + return ref.Name() +} + +// FamiliarString returns the familiar string representation +// for the given reference, familiarizing if needed. +func FamiliarString(ref Reference) string { + if nn, ok := ref.(normalizedNamed); ok { + return nn.Familiar().String() + } + return ref.String() +} + +// FamiliarMatch reports whether ref matches the specified pattern. +// See https://godoc.org/path#Match for supported patterns. +func FamiliarMatch(pattern string, ref Reference) (bool, error) { + matched, err := path.Match(pattern, FamiliarString(ref)) + if namedRef, isNamed := ref.(Named); isNamed && !matched { + matched, _ = path.Match(pattern, FamiliarName(namedRef)) + } + return matched, err +} diff --git a/remotes/docker/errcode.go b/remotes/docker/errcode.go new file mode 100644 index 000000000..7d1e54f2a --- /dev/null +++ b/remotes/docker/errcode.go @@ -0,0 +1,283 @@ +/* + Copyright The containerd Authors. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +package docker + +import ( + "encoding/json" + "fmt" + "strings" +) + +// ErrorCoder is the base interface for ErrorCode and Error allowing +// users of each to just call ErrorCode to get the real ID of each +type ErrorCoder interface { + ErrorCode() ErrorCode +} + +// ErrorCode represents the error type. The errors are serialized via strings +// and the integer format may change and should *never* be exported. +type ErrorCode int + +var _ error = ErrorCode(0) + +// ErrorCode just returns itself +func (ec ErrorCode) ErrorCode() ErrorCode { + return ec +} + +// Error returns the ID/Value +func (ec ErrorCode) Error() string { + // NOTE(stevvooe): Cannot use message here since it may have unpopulated args. + return strings.ToLower(strings.Replace(ec.String(), "_", " ", -1)) +} + +// Descriptor returns the descriptor for the error code. +func (ec ErrorCode) Descriptor() ErrorDescriptor { + d, ok := errorCodeToDescriptors[ec] + + if !ok { + return ErrorCodeUnknown.Descriptor() + } + + return d +} + +// String returns the canonical identifier for this error code. +func (ec ErrorCode) String() string { + return ec.Descriptor().Value +} + +// Message returned the human-readable error message for this error code. +func (ec ErrorCode) Message() string { + return ec.Descriptor().Message +} + +// MarshalText encodes the receiver into UTF-8-encoded text and returns the +// result. +func (ec ErrorCode) MarshalText() (text []byte, err error) { + return []byte(ec.String()), nil +} + +// UnmarshalText decodes the form generated by MarshalText. +func (ec *ErrorCode) UnmarshalText(text []byte) error { + desc, ok := idToDescriptors[string(text)] + + if !ok { + desc = ErrorCodeUnknown.Descriptor() + } + + *ec = desc.Code + + return nil +} + +// WithMessage creates a new Error struct based on the passed-in info and +// overrides the Message property. +func (ec ErrorCode) WithMessage(message string) Error { + return Error{ + Code: ec, + Message: message, + } +} + +// WithDetail creates a new Error struct based on the passed-in info and +// set the Detail property appropriately +func (ec ErrorCode) WithDetail(detail interface{}) Error { + return Error{ + Code: ec, + Message: ec.Message(), + }.WithDetail(detail) +} + +// WithArgs creates a new Error struct and sets the Args slice +func (ec ErrorCode) WithArgs(args ...interface{}) Error { + return Error{ + Code: ec, + Message: ec.Message(), + }.WithArgs(args...) +} + +// Error provides a wrapper around ErrorCode with extra Details provided. +type Error struct { + Code ErrorCode `json:"code"` + Message string `json:"message"` + Detail interface{} `json:"detail,omitempty"` + + // TODO(duglin): See if we need an "args" property so we can do the + // variable substitution right before showing the message to the user +} + +var _ error = Error{} + +// ErrorCode returns the ID/Value of this Error +func (e Error) ErrorCode() ErrorCode { + return e.Code +} + +// Error returns a human readable representation of the error. +func (e Error) Error() string { + return fmt.Sprintf("%s: %s", e.Code.Error(), e.Message) +} + +// WithDetail will return a new Error, based on the current one, but with +// some Detail info added +func (e Error) WithDetail(detail interface{}) Error { + return Error{ + Code: e.Code, + Message: e.Message, + Detail: detail, + } +} + +// WithArgs uses the passed-in list of interface{} as the substitution +// variables in the Error's Message string, but returns a new Error +func (e Error) WithArgs(args ...interface{}) Error { + return Error{ + Code: e.Code, + Message: fmt.Sprintf(e.Code.Message(), args...), + Detail: e.Detail, + } +} + +// ErrorDescriptor provides relevant information about a given error code. +type ErrorDescriptor struct { + // Code is the error code that this descriptor describes. + Code ErrorCode + + // Value provides a unique, string key, often captilized with + // underscores, to identify the error code. This value is used as the + // keyed value when serializing api errors. + Value string + + // Message is a short, human readable decription of the error condition + // included in API responses. + Message string + + // Description provides a complete account of the errors purpose, suitable + // for use in documentation. + Description string + + // HTTPStatusCode provides the http status code that is associated with + // this error condition. + HTTPStatusCode int +} + +// ParseErrorCode returns the value by the string error code. +// `ErrorCodeUnknown` will be returned if the error is not known. +func ParseErrorCode(value string) ErrorCode { + ed, ok := idToDescriptors[value] + if ok { + return ed.Code + } + + return ErrorCodeUnknown +} + +// Errors provides the envelope for multiple errors and a few sugar methods +// for use within the application. +type Errors []error + +var _ error = Errors{} + +func (errs Errors) Error() string { + switch len(errs) { + case 0: + return "" + case 1: + return errs[0].Error() + default: + msg := "errors:\n" + for _, err := range errs { + msg += err.Error() + "\n" + } + return msg + } +} + +// Len returns the current number of errors. +func (errs Errors) Len() int { + return len(errs) +} + +// MarshalJSON converts slice of error, ErrorCode or Error into a +// slice of Error - then serializes +func (errs Errors) MarshalJSON() ([]byte, error) { + var tmpErrs struct { + Errors []Error `json:"errors,omitempty"` + } + + for _, daErr := range errs { + var err Error + + switch daErr := daErr.(type) { + case ErrorCode: + err = daErr.WithDetail(nil) + case Error: + err = daErr + default: + err = ErrorCodeUnknown.WithDetail(daErr) + + } + + // If the Error struct was setup and they forgot to set the + // Message field (meaning its "") then grab it from the ErrCode + msg := err.Message + if msg == "" { + msg = err.Code.Message() + } + + tmpErrs.Errors = append(tmpErrs.Errors, Error{ + Code: err.Code, + Message: msg, + Detail: err.Detail, + }) + } + + return json.Marshal(tmpErrs) +} + +// UnmarshalJSON deserializes []Error and then converts it into slice of +// Error or ErrorCode +func (errs *Errors) UnmarshalJSON(data []byte) error { + var tmpErrs struct { + Errors []Error + } + + if err := json.Unmarshal(data, &tmpErrs); err != nil { + return err + } + + var newErrs Errors + for _, daErr := range tmpErrs.Errors { + // If Message is empty or exactly matches the Code's message string + // then just use the Code, no need for a full Error struct + if daErr.Detail == nil && (daErr.Message == "" || daErr.Message == daErr.Code.Message()) { + // Error's w/o details get converted to ErrorCode + newErrs = append(newErrs, daErr.Code) + } else { + // Error's w/ details are untouched + newErrs = append(newErrs, Error{ + Code: daErr.Code, + Message: daErr.Message, + Detail: daErr.Detail, + }) + } + } + + *errs = newErrs + return nil +} diff --git a/remotes/docker/errdesc.go b/remotes/docker/errdesc.go new file mode 100644 index 000000000..b2bd4d82b --- /dev/null +++ b/remotes/docker/errdesc.go @@ -0,0 +1,154 @@ +/* + Copyright The containerd Authors. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +package docker + +import ( + "fmt" + "net/http" + "sort" + "sync" +) + +var ( + errorCodeToDescriptors = map[ErrorCode]ErrorDescriptor{} + idToDescriptors = map[string]ErrorDescriptor{} + groupToDescriptors = map[string][]ErrorDescriptor{} +) + +var ( + // ErrorCodeUnknown is a generic error that can be used as a last + // resort if there is no situation-specific error message that can be used + ErrorCodeUnknown = Register("errcode", ErrorDescriptor{ + Value: "UNKNOWN", + Message: "unknown error", + Description: `Generic error returned when the error does not have an + API classification.`, + HTTPStatusCode: http.StatusInternalServerError, + }) + + // ErrorCodeUnsupported is returned when an operation is not supported. + ErrorCodeUnsupported = Register("errcode", ErrorDescriptor{ + Value: "UNSUPPORTED", + Message: "The operation is unsupported.", + Description: `The operation was unsupported due to a missing + implementation or invalid set of parameters.`, + HTTPStatusCode: http.StatusMethodNotAllowed, + }) + + // ErrorCodeUnauthorized is returned if a request requires + // authentication. + ErrorCodeUnauthorized = Register("errcode", ErrorDescriptor{ + Value: "UNAUTHORIZED", + Message: "authentication required", + Description: `The access controller was unable to authenticate + the client. Often this will be accompanied by a + Www-Authenticate HTTP response header indicating how to + authenticate.`, + HTTPStatusCode: http.StatusUnauthorized, + }) + + // ErrorCodeDenied is returned if a client does not have sufficient + // permission to perform an action. + ErrorCodeDenied = Register("errcode", ErrorDescriptor{ + Value: "DENIED", + Message: "requested access to the resource is denied", + Description: `The access controller denied access for the + operation on a resource.`, + HTTPStatusCode: http.StatusForbidden, + }) + + // ErrorCodeUnavailable provides a common error to report unavailability + // of a service or endpoint. + ErrorCodeUnavailable = Register("errcode", ErrorDescriptor{ + Value: "UNAVAILABLE", + Message: "service unavailable", + Description: "Returned when a service is not available", + HTTPStatusCode: http.StatusServiceUnavailable, + }) + + // ErrorCodeTooManyRequests is returned if a client attempts too many + // times to contact a service endpoint. + ErrorCodeTooManyRequests = Register("errcode", ErrorDescriptor{ + Value: "TOOMANYREQUESTS", + Message: "too many requests", + Description: `Returned when a client attempts to contact a + service too many times`, + HTTPStatusCode: http.StatusTooManyRequests, + }) +) + +var nextCode = 1000 +var registerLock sync.Mutex + +// Register will make the passed-in error known to the environment and +// return a new ErrorCode +func Register(group string, descriptor ErrorDescriptor) ErrorCode { + registerLock.Lock() + defer registerLock.Unlock() + + descriptor.Code = ErrorCode(nextCode) + + if _, ok := idToDescriptors[descriptor.Value]; ok { + panic(fmt.Sprintf("ErrorValue %q is already registered", descriptor.Value)) + } + if _, ok := errorCodeToDescriptors[descriptor.Code]; ok { + panic(fmt.Sprintf("ErrorCode %v is already registered", descriptor.Code)) + } + + groupToDescriptors[group] = append(groupToDescriptors[group], descriptor) + errorCodeToDescriptors[descriptor.Code] = descriptor + idToDescriptors[descriptor.Value] = descriptor + + nextCode++ + return descriptor.Code +} + +type byValue []ErrorDescriptor + +func (a byValue) Len() int { return len(a) } +func (a byValue) Swap(i, j int) { a[i], a[j] = a[j], a[i] } +func (a byValue) Less(i, j int) bool { return a[i].Value < a[j].Value } + +// GetGroupNames returns the list of Error group names that are registered +func GetGroupNames() []string { + keys := []string{} + + for k := range groupToDescriptors { + keys = append(keys, k) + } + sort.Strings(keys) + return keys +} + +// GetErrorCodeGroup returns the named group of error descriptors +func GetErrorCodeGroup(name string) []ErrorDescriptor { + desc := groupToDescriptors[name] + sort.Sort(byValue(desc)) + return desc +} + +// GetErrorAllDescriptors returns a slice of all ErrorDescriptors that are +// registered, irrespective of what group they're in +func GetErrorAllDescriptors() []ErrorDescriptor { + result := []ErrorDescriptor{} + + for _, group := range GetGroupNames() { + result = append(result, GetErrorCodeGroup(group)...) + } + sort.Sort(byValue(result)) + return result +} diff --git a/remotes/docker/fetcher.go b/remotes/docker/fetcher.go index ad8482fa3..2bd295ea6 100644 --- a/remotes/docker/fetcher.go +++ b/remotes/docker/fetcher.go @@ -29,7 +29,6 @@ import ( "github.com/containerd/containerd/errdefs" "github.com/containerd/containerd/images" "github.com/containerd/containerd/log" - "github.com/docker/distribution/registry/api/errcode" ocispec "github.com/opencontainers/image-spec/specs-go/v1" "github.com/pkg/errors" ) @@ -160,7 +159,7 @@ func (r dockerFetcher) open(ctx context.Context, req *request, mediatype string, if resp.StatusCode == http.StatusNotFound { return nil, errors.Wrapf(errdefs.ErrNotFound, "content at %v not found", req.String()) } - var registryErr errcode.Errors + var registryErr Errors if err := json.NewDecoder(resp.Body).Decode(®istryErr); err != nil || registryErr.Len() < 1 { return nil, errors.Errorf("unexpected status code %v: %v", req.String(), resp.Status) } diff --git a/remotes/docker/fetcher_test.go b/remotes/docker/fetcher_test.go index 701a6b345..92a308378 100644 --- a/remotes/docker/fetcher_test.go +++ b/remotes/docker/fetcher_test.go @@ -28,7 +28,6 @@ import ( "net/url" "testing" - "github.com/docker/distribution/registry/api/errcode" "github.com/pkg/errors" "gotest.tools/assert" ) @@ -131,8 +130,8 @@ func TestDockerFetcherOpen(t *testing.T) { { name: "should return status and error.message if it exists if the registry request fails", mockedStatus: 500, - mockedErr: errcode.Errors{errcode.Error{ - Code: errcode.ErrorCodeUnknown, + mockedErr: Errors{Error{ + Code: ErrorCodeUnknown, Message: "Test Error", }}, want: nil, diff --git a/remotes/docker/resolver_test.go b/remotes/docker/resolver_test.go index 38c9d6616..0929e1e12 100644 --- a/remotes/docker/resolver_test.go +++ b/remotes/docker/resolver_test.go @@ -403,7 +403,7 @@ func (m testManifest) OCIManifest() []byte { Config: m.config.Descriptor(), Layers: make([]ocispec.Descriptor, len(m.references)), } - for i, c := range append(m.references) { + for i, c := range m.references { manifest.Layers[i] = c.Descriptor() } b, _ := json.Marshal(manifest)