Merge pull request #26813 from wonderfly/choose_docker_version

Automatic merge from submit-queue

Prep for continuous Docker validation test

```release-note
Add a test config variable to specify desired Docker version to run on GCI.
```
We want to continuously validate Docker releases (#25215), on GCI. This change
adds a new test config variable, `KUBE_GCI_DOCKER_VERSION`, through which we can
specify which version of Docker we want to run on the master and nodes. This
change also patches the Jenkins e2e-runner with the ability to fetch the latest
Docker (pre)release, and sets the aforementioned variable accordingly.

Tested on my local Jenkins instance that was able to start a cluster with the latest Docker version (different from installed version) running on both master and nodes.

@dchen1107 Can you review?

cc/ @andyzheng0831 for changes in `cluster/gce/gci/helper.sh`, and @ixdy @spxtr for changes to the Jenkins e2e-runner

cc/ @kubernetes/goog-image

cluster/gce/config-test.sh

@@ -48,6 +48,7 @@ NODE_IMAGE=${KUBE_GCE_NODE_IMAGE:-"${MASTER_IMAGE}"}
 NODE_IMAGE_PROJECT=${KUBE_GCE_NODE_PROJECT:-"${MASTER_IMAGE_PROJECT}"}
 CONTAINER_RUNTIME=${KUBE_CONTAINER_RUNTIME:-docker}
 RKT_VERSION=${KUBE_RKT_VERSION:-0.5.5}
+GCI_DOCKER_VERSION=${KUBE_GCI_DOCKER_VERSION:-}
 
 NETWORK=${KUBE_GCE_NETWORK:-e2e}
 INSTANCE_PREFIX="${KUBE_GCE_INSTANCE_PREFIX:-e2e-test-${USER}}"

cluster/gce/gci/helper.sh

@@ -25,9 +25,14 @@ function ensure-gci-metadata-files {
 update_disabled
 EOF
   fi
-  if [[ ! -f "${KUBE_TEMP}/gci-docker.txt" ]]; then
-    cat >"${KUBE_TEMP}/gci-docker.txt" << EOF
+  if [[ ! -f "${KUBE_TEMP}/gci-ensure-gke-docker.txt" ]]; then
+    cat >"${KUBE_TEMP}/gci-ensure-gke-docker.txt" << EOF
 true
+EOF
+  fi
+  if [[ ! -f "${KUBE_TEMP}/gci-docker-version.txt" ]]; then
+    cat >"${KUBE_TEMP}/gci-docker-version.txt" << EOF
+${GCI_DOCKER_VERSION}
 EOF
   fi
 }
@@ -42,7 +47,8 @@ function create-node-instance-template {
     "configure-sh=${KUBE_ROOT}/cluster/gce/gci/configure.sh" \
     "cluster-name=${KUBE_TEMP}/cluster-name.txt" \
     "gci-update-strategy=${KUBE_TEMP}/gci-update.txt" \
-    "gci-ensure-gke-docker=${KUBE_TEMP}/gci-docker.txt"
+    "gci-ensure-gke-docker=${KUBE_TEMP}/gci-ensure-gke-docker.txt" \
+    "gci-docker-version=${KUBE_TEMP}/gci-docker-version.txt"
 }
 
 # create-master-instance creates the master instance. If called with
@@ -76,7 +82,7 @@ function create-master-instance {
     --scopes "storage-ro,compute-rw,monitoring,logging-write" \
     --can-ip-forward \
     --metadata-from-file \
-      "kube-env=${KUBE_TEMP}/master-kube-env.yaml,user-data=${KUBE_ROOT}/cluster/gce/gci/master.yaml,configure-sh=${KUBE_ROOT}/cluster/gce/gci/configure.sh,cluster-name=${KUBE_TEMP}/cluster-name.txt,gci-update-strategy=${KUBE_TEMP}/gci-update.txt,gci-ensure-gke-docker=${KUBE_TEMP}/gci-docker.txt" \
+      "kube-env=${KUBE_TEMP}/master-kube-env.yaml,user-data=${KUBE_ROOT}/cluster/gce/gci/master.yaml,configure-sh=${KUBE_ROOT}/cluster/gce/gci/configure.sh,cluster-name=${KUBE_TEMP}/cluster-name.txt,gci-update-strategy=${KUBE_TEMP}/gci-update.txt,gci-ensure-gke-docker=${KUBE_TEMP}/gci-ensure-gke-docker.txt,gci-docker-version=${KUBE_TEMP}/gci-docker-version.txt" \
     --disk "name=${MASTER_NAME}-pd,device-name=master-pd,mode=rw,boot=no,auto-delete=no" \
     --boot-disk-size "${MASTER_ROOT_DISK_SIZE:-10}"
 }

hack/jenkins/e2e-runner.sh

@@ -103,20 +103,24 @@ function get_latest_gci_image() {
     local image_type="$2"
     local image_index=""
     if [[ "${image_type}" == head ]]; then
-      image_index="gci-head"
+      image_index="latest-base-image-gci-head"
     elif [[ "${image_type}" == dev ]]; then
-      image_index="gci-dev"
+      image_index="latest-base-image-gci-dev"
     elif [[ "${image_type}" == beta ]]; then
-      image_index="gci-beta"
+      image_index="latest-base-image-gci-beta"
     elif [[ "${image_type}" == stable ]]; then
-      image_index="gci-stable"
+      image_index="latest-base-image-gci-stable"
+    elif [[ "${image_type}" == preview-test ]]; then
+      # A GCI preview image that is able to override its Docker installation on
+      # boot.
+      image_index="latest-test-image-gci-preview"
     fi
 
     local image=""
     # Retry the gsutil command a couple times to mitigate the effect of
     # transient server errors.
     for n in $(seq 3); do
-      image="$(gsutil cat "gs://${image_project}/image-indices/latest-base-image-${image_index}")" && break || sleep 1
+      image="$(gsutil cat "gs://${image_project}/image-indices/${image_index}")" && break || sleep 1
     done
     if [[ -z "${image}" ]]; then
       echo "Failed to find GCI image for ${image_type}"
@@ -128,6 +132,18 @@ function get_latest_gci_image() {
     rm -rf .gsutil &> /dev/null
 }
 
+function get_latest_docker_release() {
+  # Typical Docker release versions are like v1.11.2-rc1, v1.11.2, and etc.
+  local -r version_re='.*\"tag_name\":[[:space:]]+\"v([0-9\.r|c-]+)\",.*'
+  local -r latest_release="$(curl -fsSL --retry 3 https://api.github.com/repos/docker/docker/releases/latest)"
+  if [[ "${latest_release}" =~ ${version_re} ]]; then
+    echo "${BASH_REMATCH[1]}"
+  else
+    echo "Malformed Docker API response for latest release: ${latest_release}"
+    exit 1
+  fi
+}
+
 function install_google_cloud_sdk_tarball() {
     local -r tarball=$1
     local -r install_dir=$2
@@ -196,6 +212,9 @@ if [[ -n "${JENKINS_GCI_IMAGE_TYPE:-}" ]]; then
   export KUBE_GCE_MASTER_PROJECT="${gci_image_project}"
   export KUBE_GCE_MASTER_IMAGE="${gci_image}"
   export KUBE_OS_DISTRIBUTION="gci"
+  if [[ "${JENKINS_GCI_IMAGE_TYPE}" == preview-test ]]; then
+    export KUBE_GCI_DOCKER_VERSION="$(get_latest_docker_release)"
+  fi
 fi
 
 function e2e_test() {