Cache deployer - Using the same kubectl version as the server

Fixes #4505

backend/src/cache/deployer/deploy-cache-service.sh

@@ -26,6 +26,18 @@ NAMESPACE=${NAMESPACE_TO_WATCH:-kubeflow}
 MUTATING_WEBHOOK_CONFIGURATION_NAME="cache-webhook-${NAMESPACE}"
 WEBHOOK_SECRET_NAME=webhook-server-tls
 
+# Getting correct kubectl. Kubernetes only supports kubectl versions within +/-1 minor version.
+# kubectl has some resource version information hardcoded, so using too old kubectl can lead to errors
+mkdir -p "$HOME/bin"
+export PATH="$PATH:$HOME/bin"
+{
+    server_version_major_minor=$(kubectl version --output json | jq '(.serverVersion.major + "." + .serverVersion.minor)' | tr -d '+')
+    stable_build_version=$(curl -s "https://storage.googleapis.com/kubernetes-release/release/stable-${server_version_major_minor}.txt")
+    kubectl_url="https://storage.googleapis.com/kubernetes-release/release/${stable_build_version}/bin/linux/amd64/kubectl"
+    curl -L -O "$HOME/bin/kubectl" "$kubectl_url"
+    chmod +x "$HOME/bin/kubectl"
+} || true
+
 # This should fail if there are connectivity problems
 # Gotcha: Listing all objects requires list permission,
 # but when listing a single oblect kubectl will fail if it's not found