s2i: s2i rebuild broken

Bug 1366475
Bugzilla link https://bugzilla.redhat.com/show_bug.cgi?id=1366475
Detailed explanation
an attempt to pull the builder image to obtain labels was made; the correct thing was
to pull the locally build image we were rebuilding

cmd/s2i/main.go

@@ -216,7 +216,7 @@ func newCmdRebuild(cfg *api.Config) *cobra.Command {
 				cfg.PullAuthentication = docker.LoadAndGetImageRegistryAuth(r, cfg.Tag)
 			}
 
-			err := build.GenerateConfigFromLabels(cfg)
+			err := build.GenerateConfigFromLabels(cfg, true)
 			checkErr(err)
 
 			if len(args) >= 2 {

hack/test-stirunimage.sh

@@ -62,15 +62,6 @@ function test_debug() {
     echo
 }
 
-set +e
-img_count=$(docker images | grep -c sti_test/sti-fake)
-set -e
-
-if [ "${img_count}" != "10" ]; then
-    echo "You do not have necessary test images, be sure to run 'hack/build-test-images.sh' beforehand."
-    exit 1
-fi
-
 trap cleanup EXIT SIGINT
 
 echo "working dir:  ${WORK_DIR}"
@@ -114,6 +105,12 @@ check_result $? ""
 grep "Copying sources" "${WORK_DIR}/s2i-non-repo.log"
 check_result $? "${WORK_DIR}/s2i-non-repo.log"
 
+test_debug "s2i rebuild"
+s2i build https://github.com/openshift/sti-php.git --context-dir=5.5/test/test-app registry.access.redhat.com/openshift3/php-55-rhel7 rack-test-app --incremental=true --loglevel=5 &> "${WORK_DIR}/s2i-pre-rebuild.log"
+check_result $? "${WORK_DIR}/s2i-pre-rebuild.log"
+s2i rebuild rack-test-app:latest rack-test-app:v1 --force-pull=false -p never --loglevel=5 &> "${WORK_DIR}/s2i-rebuild.log"
+check_result $? "${WORK_DIR}/s2i-rebuild.log"
+
 test_debug "s2i usage"
 
 s2i usage openshift/ruby-20-centos7 &> "${WORK_DIR}/s2i-usage.log"

pkg/api/describe/describer.go

@@ -97,7 +97,7 @@ func describeBuilderImage(config *api.Config, image string, out io.Writer) {
 		Tag:                config.Tag,
 		IncrementalAuthentication: config.IncrementalAuthentication,
 	}
-	build.GenerateConfigFromLabels(c)
+	build.GenerateConfigFromLabels(c, false)
 	if len(c.DisplayName) > 0 {
 		fmt.Fprintf(out, "Builder Name:\t%s\n", c.DisplayName)
 	}

pkg/build/config.go

@@ -9,8 +9,14 @@ import (
 
 // GenerateConfigFromLabels generates the S2I Config struct from the Docker
 // image labels.
-func GenerateConfigFromLabels(config *api.Config) error {
-	result, err := docker.GetBuilderImage(config)
+func GenerateConfigFromLabels(config *api.Config, rebuild bool) error {
+	var result *docker.PullResult
+	var err error
+	if rebuild {
+		result, err = docker.GetRebuildImage(config)
+	} else {
+		result, err = docker.GetBuilderImage(config)
+	}
 	if err != nil {
 		return err
 	}

pkg/docker/util.go

@@ -286,6 +286,28 @@ func GetBuilderImage(config *api.Config) (*PullResult, error) {
 	return r, nil
 }
 
+// GetRebuildImage obtains the metadata information for the image
+// specified in a s2i rebuild operation.  Assumptions are made that
+// the build is available locally since it should have been previously built.
+func GetRebuildImage(config *api.Config) (*PullResult, error) {
+	d, err := New(config.DockerConfig, config.PullAuthentication)
+	if err != nil {
+		return nil, err
+	}
+
+	r, err := PullImage(config.Tag, d, api.PullNever, false)
+	if err != nil {
+		return nil, err
+	}
+
+	err = CheckAllowedUser(d, config.Tag, config.AllowedUIDs, r.OnBuild)
+	if err != nil {
+		return nil, err
+	}
+
+	return r, nil
+}
+
 // GetRuntimeImage processes the config and performs operations necessary to make
 // the Docker image specified as RuntimeImage available locally.
 func GetRuntimeImage(config *api.Config, docker Docker) error {