registry/docs/handlers/catalog.go
Patrick Devine bf62b7ebb7 Create Repositories method
This change removes the Catalog Service and replaces it with a more
simplistic Repositories() method for obtaining a catalog of all
repositories.  The Repositories method takes a pre-allocated slice
and fills it up to the size of the slice and returns the amount
filled.  The catalog is returned lexicographically and will start
being filled from the last entry passed to Repositories().  If there
are no more entries to fill, io.EOF will be returned.

Signed-off-by: Patrick Devine <patrick.devine@docker.com>

Conflicts:
	registry/client/repository.go
	registry/handlers/api_test.go
2015-07-21 21:45:14 -07:00

95 lines
2.1 KiB
Go

package handlers
import (
"encoding/json"
"fmt"
"io"
"net/http"
"net/url"
"strconv"
"github.com/docker/distribution/registry/api/errcode"
"github.com/gorilla/handlers"
)
const maximumReturnedEntries = 100
func catalogDispatcher(ctx *Context, r *http.Request) http.Handler {
catalogHandler := &catalogHandler{
Context: ctx,
}
return handlers.MethodHandler{
"GET": http.HandlerFunc(catalogHandler.GetCatalog),
}
}
type catalogHandler struct {
*Context
}
type catalogAPIResponse struct {
Repositories []string `json:"repositories"`
}
func (ch *catalogHandler) GetCatalog(w http.ResponseWriter, r *http.Request) {
var moreEntries = true
q := r.URL.Query()
lastEntry := q.Get("last")
maxEntries, err := strconv.Atoi(q.Get("n"))
if err != nil || maxEntries < 0 {
maxEntries = maximumReturnedEntries
}
repos := make([]string, maxEntries)
filled, err := ch.App.registry.Repositories(ch.Context, repos, lastEntry)
if err == io.EOF {
moreEntries = false
} else if err != nil {
ch.Errors = append(ch.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
return
}
w.Header().Set("Content-Type", "application/json; charset=utf-8")
// Add a link header if there are more entries to retrieve
if moreEntries {
lastEntry = repos[len(repos)-1]
urlStr, err := createLinkEntry(r.URL.String(), maxEntries, lastEntry)
if err != nil {
ch.Errors = append(ch.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
return
}
w.Header().Set("Link", urlStr)
}
enc := json.NewEncoder(w)
if err := enc.Encode(catalogAPIResponse{
Repositories: repos[0:filled],
}); err != nil {
ch.Errors = append(ch.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
return
}
}
// Use the original URL from the request to create a new URL for
// the link header
func createLinkEntry(origURL string, maxEntries int, lastEntry string) (string, error) {
calledURL, err := url.Parse(origURL)
if err != nil {
return "", err
}
v := url.Values{}
v.Add("n", strconv.Itoa(maxEntries))
v.Add("last", lastEntry)
calledURL.RawQuery = v.Encode()
calledURL.Fragment = ""
urlStr := fmt.Sprintf("<%s>; rel=\"next\"", calledURL.String())
return urlStr, nil
}