Add kind coverage dump script to experiment/

Author: Katharine

experiment/dump_kind_coverage.sh

@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+# Copyright 2018 The Kubernetes 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.
+
+# Dump coverage files from a kind node.
+# Usage: dump_kind_coverage.sh [cluster] [destination]
+
+# Executes a command inside the node running the kind cluster named ${cluster}.
+exec_in_node() {
+   docker exec $(docker ps -f name=kind-${cluster}-control-plane --format '{{.ID}}') "$@"
+}
+
+# Executes a command in container $1 in the kind cluster named ${cluster}
+exec_in_container() {
+  local container="$1"
+  shift
+  exec_in_node bash -c "docker exec \"\$(docker ps -f label=io.kubernetes.container.name=${container} --format '{{.ID}}')\" $*"
+}
+
+# Produces the coverage log for service $1 in the kind cluster named ${cluster}
+get_container_log() {
+  local service="$1"
+  exec_in_container "${service}" cat "/tmp/k8s-${service}.cov"
+}
+
+# Dumps logs from the cluster named $1 to $2.
+dump_logs() {
+  local cluster="$1"
+  local destination="$2"
+  get_container_log "kube-apiserver" > "${destination}/kube-apiserver.cov"
+  get_container_log "kube-scheduler" > "${destination}/kube-scheduler.cov"
+  get_container_log "kube-controller-manager" > "${destination}/kube-controller-manager.cov"
+  get_container_log "kube-proxy" > "${destination}/kube-proxy.cov"
+  exec_in_node cat /tmp/k8s-kubelet.cov > "${destination}/kubelet.cov"
+}
+
+dump_logs "$@"