Merge pull request #18488 from yifan-gu/dockerized_python

Auto commit by PR queue bot

build/common.sh

@@ -820,6 +820,16 @@ function kube::release::write_addon_docker_images_for_server() {
       ) &
     done
 
+    if [[ ! -z "${BUILD_PYTHON_IMAGE:-}" ]]; then
+      (
+        kube::log::status "Building Docker python image"
+        
+        local img_name=python:2.7-slim-pyyaml
+        docker build -t "${img_name}" "${KUBE_ROOT}/cluster/addons/python-image"
+        docker save "${img_name}" > "${1}/${img_name}.tar"
+      ) &
+    fi
+
     kube::util::wait-for-jobs || { kube::log::error "unable to pull or write addon image"; return 1; }
     kube::log::status "Addon images done"
   )

cluster/addons/README.md

@@ -58,6 +58,8 @@ of:
      pods.
   1. Note that this cannot happen for Services as their version is always empty.
 
+Note that in order to run the updator script, python is required on the machine.
+For OS distros that don't have python installed, a python container will be used.
 
 
 

cluster/addons/python-image/Dockerfile

@@ -0,0 +1,3 @@
+FROM python:2.7-slim
+
+RUN pip install pyyaml

cluster/addons/python-image/README.md

@@ -0,0 +1,6 @@
+# Python image
+
+The python image here is used by OS distros that don't have python installed to
+run python scripts to parse the yaml files in the addon updator script.
+
+[![Analytics](https://kubernetes-site.appspot.com/UA-36037335-10/GitHub/cluster/addons/python-image/README.md?pixel)]()

cluster/saltbase/salt/kube-addons/kube-addon-update.sh

@@ -98,7 +98,7 @@ function log() {
 function get-object-kind-from-file() {
     # prints to stdout, so log cannot be used
     #WARNING: only yaml is supported
-    cat $1 | python -c '''
+    cat $1 | ${PYTHON} -c '''
 try:
         import pipes,sys,yaml
         y = yaml.load(sys.stdin)
@@ -120,7 +120,7 @@ function get-object-nsname-from-file() {
     # prints to stdout, so log cannot be used
     #WARNING: only yaml is supported
     #addons that do not specify a namespace are assumed to be in "default".
-    cat $1 | python -c '''
+    cat $1 | ${PYTHON} -c '''
 try:
         import pipes,sys,yaml
         y = yaml.load(sys.stdin)

cluster/saltbase/salt/kube-addons/kube-addons.sh

@@ -24,6 +24,16 @@ ADDON_CHECK_INTERVAL_SEC=${TEST_ADDON_CHECK_INTERVAL_SEC:-600}
 SYSTEM_NAMESPACE=kube-system
 token_dir=${TOKEN_DIR:-/srv/kubernetes}
 
+function ensure_python() {
+  if ! python --version > /dev/null 2>&1; then    
+    echo "No python on the machine, will use a python image"
+    local -r PYTHON_IMAGE=python:2.7-slim-pyyaml
+    export PYTHON="docker run --interactive --rm --net=none ${PYTHON_IMAGE} python"
+  else
+    export PYTHON=python
+  fi
+}
+
 function create-kubeconfig-secret() {
   local -r token=$1
   local -r username=$2
@@ -152,11 +162,16 @@ function load-docker-images() {
 # managed result is of that. Start everything below that directory.
 echo "== Kubernetes addon manager started at $(date -Is) with ADDON_CHECK_INTERVAL_SEC=${ADDON_CHECK_INTERVAL_SEC} =="
 
+# Load any images that we may need
+load-docker-images /srv/salt/kube-addons-images
+
+ensure_python
+
 # Load the kube-env, which has all the environment variables we care
 # about, in a flat yaml format.
 kube_env_yaml="/var/cache/kubernetes-install/kube_env.yaml"
 if [ ! -e "${kubelet_kubeconfig_file}" ]; then
-  eval $(python -c '''
+  eval $(${PYTHON} -c '''
 import pipes,sys,yaml
 
 for k,v in yaml.load(sys.stdin).iteritems():
@@ -164,8 +179,6 @@ for k,v in yaml.load(sys.stdin).iteritems():
 ''' < "${kube_env_yaml}")
 fi
 
-# Load any images that we may need
-load-docker-images /srv/salt/kube-addons-images
 
 # Create the namespace that will be used to host the cluster-level add-ons.
 start_addon /etc/kubernetes/addons/namespace.yaml 100 10 "" &