|
| 1 | +package server |
| 2 | + |
| 3 | +import ( |
| 4 | + "errors" |
| 5 | + "fmt" |
| 6 | + "io" |
| 7 | + "time" |
| 8 | + |
| 9 | + apierrors "k8s.io/apimachinery/pkg/api/errors" |
| 10 | + metav1 "k8s.io/apimachinery/pkg/apis/meta/v1" |
| 11 | + "k8s.io/apimachinery/pkg/util/cache" |
| 12 | + |
| 13 | + "github.com/docker/distribution/context" |
| 14 | + |
| 15 | + imageapiv1 "github.com/openshift/api/image/v1" |
| 16 | + "github.com/openshift/image-registry/pkg/dockerregistry/server/client" |
| 17 | +) |
| 18 | + |
| 19 | +const paginationEntryTTL = time.Minute |
| 20 | + |
| 21 | +// RepositoryEnumerator allows to enumerate repositories known to the registry. |
| 22 | +type RepositoryEnumerator interface { |
| 23 | + // EnumerateRepositories fills the given repos slice with image stream names. The slice's length |
| 24 | + // determines the maximum number of repositories returned. The repositories are lexicographically sorted. |
| 25 | + // The last argument allows for pagination. It is the offset in the catalog. Returned is a number of |
| 26 | + // repositories filled. If there are no more repositories to return, io.EOF is returned. |
| 27 | + EnumerateRepositories(ctx context.Context, repos []string, last string) (n int, err error) |
| 28 | +} |
| 29 | + |
| 30 | +// cachingRepositoryEnumerator is an enumerator that supports chunking by caching associations between |
| 31 | +// repository names and opaque continuation tokens. |
| 32 | +type cachingRepositoryEnumerator struct { |
| 33 | + client client.RegistryClient |
| 34 | + // a cache of opaque continue tokens for repository enumeration |
| 35 | + cache *cache.LRUExpireCache |
| 36 | +} |
| 37 | + |
| 38 | +var _ RepositoryEnumerator = &cachingRepositoryEnumerator{} |
| 39 | + |
| 40 | +// NewCachingRepositoryEnumerator returns a new caching repository enumerator. |
| 41 | +func NewCachingRepositoryEnumerator(client client.RegistryClient, cache *cache.LRUExpireCache) RepositoryEnumerator { |
| 42 | + return &cachingRepositoryEnumerator{ |
| 43 | + client: client, |
| 44 | + cache: cache, |
| 45 | + } |
| 46 | +} |
| 47 | + |
| 48 | +type isHandlerFunc func(is *imageapiv1.ImageStream) error |
| 49 | + |
| 50 | +var errNoSpaceInSlice = errors.New("no space in slice") |
| 51 | +var errEnumerationFinished = errors.New("enumeration finished") |
| 52 | + |
| 53 | +func (re *cachingRepositoryEnumerator) EnumerateRepositories( |
| 54 | + ctx context.Context, |
| 55 | + repos []string, |
| 56 | + last string, |
| 57 | +) (n int, err error) { |
| 58 | + if len(repos) == 0 { |
| 59 | + // Client explicitly requested 0 results. Returning nil for error seems more appropriate but this is |
| 60 | + // more in line with upstream does. Returning nil actually makes the upstream code panic. |
| 61 | + // TODO: patch upstream? /_catalog?n=0 results in 500 |
| 62 | + return 0, errNoSpaceInSlice |
| 63 | + } |
| 64 | + |
| 65 | + err = re.enumerateImageStreams(ctx, int64(len(repos)), last, func(is *imageapiv1.ImageStream) error { |
| 66 | + name := fmt.Sprintf("%s/%s", is.Namespace, is.Name) |
| 67 | + repos[n] = name |
| 68 | + n++ |
| 69 | + |
| 70 | + if n >= len(repos) { |
| 71 | + return errEnumerationFinished |
| 72 | + } |
| 73 | + |
| 74 | + return nil |
| 75 | + }) |
| 76 | + |
| 77 | + switch err { |
| 78 | + case errEnumerationFinished: |
| 79 | + err = nil |
| 80 | + case nil: |
| 81 | + err = io.EOF |
| 82 | + } |
| 83 | + |
| 84 | + return |
| 85 | +} |
| 86 | + |
| 87 | +func (r *cachingRepositoryEnumerator) enumerateImageStreams( |
| 88 | + ctx context.Context, |
| 89 | + limit int64, |
| 90 | + last string, |
| 91 | + handler isHandlerFunc, |
| 92 | +) error { |
| 93 | + var ( |
| 94 | + start string |
| 95 | + warned bool |
| 96 | + ) |
| 97 | + |
| 98 | + client, ok := userClientFrom(ctx) |
| 99 | + if !ok { |
| 100 | + context.GetLogger(ctx).Warnf("user token not set, falling back to registry client") |
| 101 | + osClient, err := r.client.Client() |
| 102 | + if err != nil { |
| 103 | + return err |
| 104 | + } |
| 105 | + client = osClient |
| 106 | + } |
| 107 | + |
| 108 | + if len(last) > 0 { |
| 109 | + if c, ok := r.cache.Get(last); !ok { |
| 110 | + context.GetLogger(ctx).Warnf("failed to find opaque continue token for last repository=%q -> requesting the full image stream list instead of %d items", last, limit) |
| 111 | + warned = true |
| 112 | + limit = 0 |
| 113 | + } else { |
| 114 | + start = c.(string) |
| 115 | + } |
| 116 | + } |
| 117 | + |
| 118 | + iss, err := client.ImageStreams("").List(metav1.ListOptions{ |
| 119 | + Limit: limit, |
| 120 | + Continue: start, |
| 121 | + }) |
| 122 | + if apierrors.IsResourceExpired(err) { |
| 123 | + context.GetLogger(ctx).Warnf("continuation token expired (%v) -> requesting the full image stream list", err) |
| 124 | + iss, err = client.ImageStreams("").List(metav1.ListOptions{}) |
| 125 | + warned = true |
| 126 | + } |
| 127 | + |
| 128 | + if err != nil { |
| 129 | + return err |
| 130 | + } |
| 131 | + |
| 132 | + warnBrokenPagination := func(msg string) { |
| 133 | + if !warned { |
| 134 | + context.GetLogger(ctx).Warnf("pagination not working: %s; the master API does not support chunking", msg) |
| 135 | + warned = true |
| 136 | + } |
| 137 | + } |
| 138 | + |
| 139 | + if limit > 0 && limit < int64(len(iss.Items)) { |
| 140 | + warnBrokenPagination(fmt.Sprintf("received %d image streams instead of requested maximum %d", len(iss.Items), limit)) |
| 141 | + } |
| 142 | + if len(iss.Items) > 0 && len(iss.ListMeta.Continue) > 0 { |
| 143 | + last := iss.Items[len(iss.Items)-1] |
| 144 | + r.cache.Add(fmt.Sprintf("%s/%s", last.Namespace, last.Name), iss.ListMeta.Continue, paginationEntryTTL) |
| 145 | + } |
| 146 | + |
| 147 | + for _, is := range iss.Items { |
| 148 | + name := fmt.Sprintf("%s/%s", is.Namespace, is.Name) |
| 149 | + if len(last) > 0 && name <= last { |
| 150 | + if !warned { |
| 151 | + warnBrokenPagination(fmt.Sprintf("received unexpected repository name %q -"+ |
| 152 | + " lexicographically preceding the requested %q", name, last)) |
| 153 | + } |
| 154 | + continue |
| 155 | + } |
| 156 | + err := handler(&is) |
| 157 | + if err != nil { |
| 158 | + return err |
| 159 | + } |
| 160 | + } |
| 161 | + |
| 162 | + return nil |
| 163 | +} |
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