prow.sh: update to kind 0.9, support Kubernetes 1.19

kind 0.9 adds support for recent Kubernetes releases like 1.19 and
simplifies configuration of feature gates and runtime config.

With Kubernetes 1.19, new feature gates were introduced which might
become relevant for the alpha Prow jobs.

The updated kind release comes with images for different Kubernetes
releases than the one before. To avoid breaking existing jobs,
the script now picks kind images automatically. As an additional
bonus, it then uses images with hash, i.e. it's less likely to break
if those image tags change because of a future kind release.

Author: pohly

Diff for: prow.sh

@@ -52,26 +52,6 @@ configvar () {
     eval echo "\$3:" "$1=\${$1}"
 }
 
-# Takes the minor version of $CSI_PROW_KUBERNETES_VERSION and overrides it to
-# $1 if they are equal minor versions. Ignores versions that begin with
-# "release-".
-override_k8s_version () {
-    local current_minor_version
-    local override_minor_version
-
-    # Ignore: See if you can use ${variable//search/replace} instead.
-    # shellcheck disable=SC2001
-    current_minor_version="$(echo "${CSI_PROW_KUBERNETES_VERSION}" | sed -e 's/\([0-9]*\)\.\([0-9]*\).*/\1\.\2/')"
-
-    # Ignore: See if you can use ${variable//search/replace} instead.
-    # shellcheck disable=SC2001
-    override_minor_version="$(echo "${1}" | sed -e 's/\([0-9]*\)\.\([0-9]*\).*/\1\.\2/')"
-    if [ "${current_minor_version}" == "${override_minor_version}" ]; then
-      CSI_PROW_KUBERNETES_VERSION="$1"
-      echo "Overriding CSI_PROW_KUBERNETES_VERSION with $1: $CSI_PROW_KUBERNETES_VERSION"
-    fi
-}
-
 # Prints the value of a variable + version suffix, falling back to variable + "LATEST".
 get_versioned_variable () {
     local var="$1"
@@ -107,9 +87,19 @@ configvar CSI_PROW_GO_VERSION_KIND "${CSI_PROW_GO_VERSION_BUILD}" "Go version fo
 configvar CSI_PROW_GO_VERSION_GINKGO "${CSI_PROW_GO_VERSION_BUILD}" "Go version for building ginkgo" # depends on CSI_PROW_GINKGO_VERSION below
 
 # kind version to use. If the pre-installed version is different,
-# the desired version is downloaded from https://github.com/kubernetes-sigs/kind/releases/download/
+# the desired version is downloaded from https://github.com/kubernetes-sigs/kind/releases
 # (if available), otherwise it is built from source.
-configvar CSI_PROW_KIND_VERSION "v0.6.0" "kind"
+configvar CSI_PROW_KIND_VERSION "v0.9.0" "kind"
+
+# kind images to use. Must match the kind version.
+# The release notes of each kind release list the supported images.
+configvar CSI_PROW_KIND_IMAGES "kindest/node:v1.19.1@sha256:98cf5288864662e37115e362b23e4369c8c4a408f99cbc06e58ac30ddc721600
+kindest/node:v1.18.8@sha256:f4bcc97a0ad6e7abaf3f643d890add7efe6ee4ab90baeb374b4f41a4c95567eb
+kindest/node:v1.17.11@sha256:5240a7a2c34bf241afb54ac05669f8a46661912eab05705d660971eeb12f6555
+kindest/node:v1.16.15@sha256:a89c771f7de234e6547d43695c7ab047809ffc71a0c3b65aa54eda051c45ed20
+kindest/node:v1.15.12@sha256:d9b939055c1e852fe3d86955ee24976cab46cba518abcb8b13ba70917e6547a6
+kindest/node:v1.14.10@sha256:ce4355398a704fca68006f8a29f37aafb49f8fc2f64ede3ccd0d9198da910146
+kindest/node:v1.13.12@sha256:1c1a48c2bfcbae4d5f4fa4310b5ed10756facad0b7a2ca93c7a4b5bae5db29f5" "kind images"
 
 # Use kind node-image --type=bazel by default, but allow to disable that.
 configvar CSI_PROW_USE_BAZEL true "use Bazel during 'kind node-image' invocation"
@@ -127,10 +117,13 @@ configvar CSI_PROW_GINKO_PARALLEL "-p" "Ginko parallelism parameter(s)"
 configvar CSI_PROW_BUILD_JOB true "building code in repo enabled"
 
 # Kubernetes version to test against. This must be a version number
-# (like 1.13.3) for which there is a pre-built kind image (see
-# https://hub.docker.com/r/kindest/node/tags), "latest" (builds
-# Kubernetes from the master branch) or "release-x.yy" (builds
-# Kubernetes from a release branch).
+# (like 1.13.3), "latest" (builds Kubernetes from the master branch)
+# or "release-x.yy" (builds Kubernetes from a release branch).
+#
+# The patch version is only relevant for picking the E2E test suite
+# that is used for testing. The script automatically picks
+# the kind images for the major/minor version of Kubernetes
+# that the kind release supports.
 #
 # This can also be a version that was not released yet at the time
 # that the settings below were chose. The script will then
@@ -139,16 +132,6 @@ configvar CSI_PROW_BUILD_JOB true "building code in repo enabled"
 # deprecating or changing the implementation of an alpha feature.
 configvar CSI_PROW_KUBERNETES_VERSION 1.17.0 "Kubernetes"
 
-# This is a hack to workaround the issue that each version
-# of kind currently only supports specific patch versions of
-# Kubernetes. We need to override CSI_PROW_KUBERNETES_VERSION
-# passed in by our CI/pull jobs to the versions that
-# kind v0.5.0 supports.
-#
-# If the version is prefixed with "release-", then nothing
-# is overridden.
-override_k8s_version "1.15.3"
-
 # CSI_PROW_KUBERNETES_VERSION reduced to first two version numbers and
 # with underscore (1_13 instead of 1.13.3) and in uppercase (LATEST
 # instead of latest).
@@ -338,9 +321,7 @@ configvar CSI_PROW_E2E_ALPHA "$(get_versioned_variable CSI_PROW_E2E_ALPHA "${csi
 # kubernetes-csi components must be updated, either by disabling
 # the failing test for "latest" or by updating the test and not running
 # it anymore for older releases.
-# TODO: add new CSI_PROW_ALPHA_GATES_xxx entry for future Kubernetes releases and
-# add new gates to CSI_PROW_E2E_ALPHA_GATES_LATEST.
-configvar CSI_PROW_E2E_ALPHA_GATES_LATEST '' "alpha feature gates for latest Kubernetes"
+configvar CSI_PROW_E2E_ALPHA_GATES_LATEST 'GenericEphemeralVolume=true,CSIStorageCapacity=true' "alpha feature gates for latest Kubernetes"
 configvar CSI_PROW_E2E_ALPHA_GATES "$(get_versioned_variable CSI_PROW_E2E_ALPHA_GATES "${csi_prow_kubernetes_version_suffix}")" "alpha E2E feature gates"
 
 # Which external-snapshotter tag to use for the snapshotter CRD and snapshot-controller deployment
@@ -504,6 +485,22 @@ list_gates () (
     done
 )
 
+# Turn feature gates in the format foo=true,bar=false into
+# a YAML map with the corresponding API groups for use
+# with https://kind.sigs.k8s.io/docs/user/configuration/#runtime-config
+list_api_groups () (
+    set -f; IFS=','
+    # Ignore: Double quote to prevent globbing and word splitting.
+    # shellcheck disable=SC2086
+    set -- $1
+    while [ "$1" ]; do
+        if [ "$1" = 'CSIStorageCapacity=true' ]; then
+            echo '   "storage.k8s.io/v1alpha1": "true"'
+        fi
+        shift
+    done
+)
+
 go_version_for_kubernetes () (
     local path="$1"
     local version="$2"
@@ -533,8 +530,21 @@ start_cluster () {
         run kind delete cluster --name=csi-prow || die "kind delete failed"
     fi
 
-    # Build from source?
-    if [[ "${CSI_PROW_KUBERNETES_VERSION}" =~ ^release-|^latest$ ]]; then
+    # Try to find a pre-built kind image if asked to use a specific version.
+    if ! [[ "${CSI_PROW_KUBERNETES_VERSION}" =~ ^release-|^latest$ ]]; then
+        # Ignore: See if you can use ${variable//search/replace} instead.
+        # shellcheck disable=SC2001
+        major_minor=$(echo "${CSI_PROW_KUBERNETES_VERSION}" | sed -e 's/^\([0-9]*\)\.\([0-9]*\).*/\1.\2/')
+        for i in ${CSI_PROW_KIND_IMAGES}; do
+            if echo "$i" | grep -q "kindest/node:v${major_minor}"; then
+                image="$i"
+                break
+            fi
+        done
+    fi
+
+    # Need to build from source?
+    if ! [ "$image" ]; then
         if ! ${csi_prow_kind_have_kubernetes}; then
             local version="${CSI_PROW_KUBERNETES_VERSION}"
             if [ "$version" = "latest" ]; then
@@ -552,63 +562,19 @@ start_cluster () {
             csi_prow_kind_have_kubernetes=true
         fi
         image="csiprow/node:latest"
-    else
-        image="kindest/node:v${CSI_PROW_KUBERNETES_VERSION}"
     fi
     cat >"${CSI_PROW_WORK}/kind-config.yaml" <<EOF
 kind: Cluster
-apiVersion: kind.sigs.k8s.io/v1alpha3
+apiVersion: kind.x-k8s.io/v1alpha4
 nodes:
 - role: control-plane
 - role: worker
 - role: worker
-EOF
-
-    # kubeadm has API dependencies between apiVersion and Kubernetes version
-    # 1.15+ requires kubeadm.k8s.io/v1beta2
-    # We only run alpha tests against master so we don't need to maintain
-    # different patches for different Kubernetes releases.
-    if [[ -n "$gates" ]]; then
-        cat >>"${CSI_PROW_WORK}/kind-config.yaml" <<EOF
-kubeadmConfigPatches:
-- |
-  apiVersion: kubeadm.k8s.io/v1beta2
-  kind: ClusterConfiguration
-  metadata:
-    name: config
-  apiServer:
-    extraArgs:
-      "feature-gates": "$gates"
-  controllerManager:
-    extraArgs:
-      "feature-gates": "$gates"
-  scheduler:
-    extraArgs:
-      "feature-gates": "$gates"
-- |
-  apiVersion: kubeadm.k8s.io/v1beta2
-  kind: InitConfiguration
-  metadata:
-    name: config
-  nodeRegistration:
-    kubeletExtraArgs:
-      "feature-gates": "$gates"
-- |
-  apiVersion: kubelet.config.k8s.io/v1beta1
-  kind: KubeletConfiguration
-  metadata:
-    name: config
-  featureGates:
-$(list_gates "$gates")
-- |
-  apiVersion: kubeproxy.config.k8s.io/v1alpha1
-  kind: KubeProxyConfiguration
-  metadata:
-    name: config
-  featureGates:
+featureGates:
 $(list_gates "$gates")
+runtimeConfig:
+$(list_api_groups "$gates")
 EOF
-    fi
 
     info "kind-config.yaml:"
     cat "${CSI_PROW_WORK}/kind-config.yaml"