Merge pull request #21455 from vrothberg/resolve-endpoint

add new libpod/images/$name/resolve endpoint

pkg/api/handlers/libpod/images.go

@@ -15,6 +15,8 @@ import (
 	"github.com/containers/common/libimage"
 	"github.com/containers/common/pkg/ssh"
 	"github.com/containers/image/v5/manifest"
+	"github.com/containers/image/v5/pkg/shortnames"
+	"github.com/containers/image/v5/types"
 	"github.com/containers/podman/v4/libpod"
 	"github.com/containers/podman/v4/libpod/define"
 	"github.com/containers/podman/v4/pkg/api/handlers"
@@ -720,3 +722,36 @@ func ImageScp(w http.ResponseWriter, r *http.Request) {
 
 	utils.WriteResponse(w, http.StatusOK, &reports.ScpReport{Id: rep.Names[0]})
 }
+
+// Resolve the passed (short) name to one more candidates it may resolve to.
+// See https://www.redhat.com/sysadmin/container-image-short-names.
+//
+// One user of this endpoint is Podman Desktop which needs to figure out where
+// an image may resolve to.
+func ImageResolve(w http.ResponseWriter, r *http.Request) {
+	runtime := r.Context().Value(api.RuntimeKey).(*libpod.Runtime)
+	name := utils.GetName(r)
+
+	mode := types.ShortNameModeDisabled
+	sys := runtime.SystemContext()
+	sys.ShortNameMode = &mode
+
+	resolved, err := shortnames.Resolve(sys, name)
+	if err != nil {
+		utils.Error(w, http.StatusBadRequest, fmt.Errorf("resolving %q: %w", name, err))
+		return
+	}
+
+	if len(resolved.PullCandidates) == 0 { // Should never happen but let's be defensive.
+		utils.Error(w, http.StatusInternalServerError, fmt.Errorf("name %q did not resolve to any candidate", name))
+		return
+	}
+
+	names := make([]string, 0, len(resolved.PullCandidates))
+	for _, candidate := range resolved.PullCandidates {
+		names = append(names, candidate.Value.String())
+	}
+
+	report := handlers.LibpodImagesResolveReport{Names: names}
+	utils.WriteResponse(w, http.StatusOK, report)
+}

pkg/api/handlers/types.go

@@ -34,6 +34,12 @@ type LibpodImagesRemoveReport struct {
 	Errors []string
 }
 
+// LibpodImagesResolveReport includes a list of fully-qualified image references.
+type LibpodImagesResolveReport struct {
+	// Fully-qualified image references.
+	Names []string
+}
+
 type ContainersPruneReport struct {
 	docker.ContainersPruneReport
 }

pkg/api/server/register_images.go

@@ -1690,5 +1690,27 @@ func (s *APIServer) registerImagesHandlers(r *mux.Router) error {
 	//   500:
 	//     $ref: '#/responses/internalError'
 	r.Handle(VersionedPath("/libpod/images/scp/{name:.*}"), s.APIHandler(libpod.ImageScp)).Methods(http.MethodPost)
+	// swagger:operation GET /libpod/images/{name}/resolve libpod ImageResolveLibpod
+	// ---
+	// tags:
+	//  - images
+	// summary: Resolve an image (short) name
+	// description: Resolve the passed image name to a list of fully-qualified images referring to container registries.
+	// parameters:
+	//  - in: path
+	//    name: name
+	//    type: string
+	//    required: true
+	//    description: the (short) name to resolve
+	// produces:
+	// - application/json
+	// responses:
+	//   204:
+	//     description: resolved image names
+	//   400:
+	//     $ref: "#/responses/badParamError"
+	//   500:
+	//     $ref: '#/responses/internalError'
+	r.Handle(VersionedPath("/libpod/images/{name:.*}/resolve"), s.APIHandler(libpod.ImageResolve)).Methods(http.MethodGet)
 	return nil
 }

test/apiv2/10-images.at

@@ -325,4 +325,22 @@ t DELETE images/$iid_test2?noprune=false 200
 t GET libpod/images/$iid_test1/exists 404
 t GET libpod/images/$iid_test2/exists 404
 
+# If the /resolve tests fail, make sure to use ../registries.conf for the
+# podman-service.
+
+# With an alias, we only get one item back.
+t GET libpod/images/podman-desktop-test123:this/resolve 200 \
+  .Names[0]="florent.fr/will/like:this"
+
+# If no alias matches, we will get a candidate for each unqualified-search
+# registry.
+t GET libpod/images/no-alias-for-sure/resolve 200 \
+  .Names[0]="docker.io/library/no-alias-for-sure:latest" \
+  .Names[1]="quay.io/no-alias-for-sure:latest" \
+  .Names[2]="registry.fedoraproject.org/no-alias-for-sure:latest"
+
+# Test invalid input.
+t GET libpod/images/noCAPITALcharAllowed/resolve 400 \
+  .cause="repository name must be lowercase"
+
 # vim: filetype=sh

test/apiv2/test-apiv2

@@ -448,6 +448,7 @@ function start_service() {
         $PODMAN_BIN unshare true
     fi
 
+    CONTAINERS_REGISTRIES_CONF=$TESTS_DIR/../registries.conf \
         $PODMAN_BIN \
         --root $WORKDIR/server_root --syslog=true \
         system service \

test/registries.conf

@@ -21,3 +21,7 @@ location="quay.io/libpod"
 [[registry]]
 location="localhost:5000"
 insecure=true
+
+# Alias used in tests.
+[aliases]
+  "podman-desktop-test123"="florent.fr/will/like"