Add kubebuilder installation for presubmit

Author: engedaam

.github/actions/install-deps/actions.yaml

@@ -0,0 +1,30 @@
+name: InstallDependencies
+description: 'Installs Go Downloads and installs Karpenter Dependencies'
+inputs:
+  k8sVersion:
+    description: Kubernetes version to use when installing the toolchain
+    default: "1.24.x"
+runs:
+  using: "composite"
+  steps:
+    - uses: actions/setup-go@3041bf56c941b39c61721a86cd11f3bb1338122a # v5.2.0
+      id: setup-go
+      with:
+        go-version-file: go.mod
+        check-latest: true
+        cache-dependency-path: "**/go.sum"
+    # Root path permission workaround for caching https://github.com/actions/cache/issues/845#issuecomment-1252594999
+    - run: sudo chown "$USER" /usr/local
+      shell: bash
+    - uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57 # v4.2.0
+      id: cache-toolchain
+      with:
+        path: |
+          /usr/local/kubebuilder/bin
+          ~/go/bin
+        # Added go version to compensate for this issue with govulncheck: https://github.com/golang/go/issues/65590. Could re-evaluate if this is necessary once the
+        # upstream go issue is corrected and if this is causing too many cache misses.
+        key: ${{ runner.os }}-${{ inputs.k8sVersion }}-${{ steps.setup-go.outputs.go-version }}-toolchain-cache-${{ hashFiles('hack/toolchain.sh') }}
+    - if: ${{ steps.cache-toolchain.outputs.cache-hit != 'true' }}
+      shell: bash
+      run: K8S_VERSION=${{ inputs.k8sVersion }} make toolchain

.github/toolchain.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+K8S_VERSION="${K8S_VERSION:="1.31.x"}"
+KUBEBUILDER_ASSETS="/usr/local/kubebuilder/bin"
+
+main() {
+    kubebuilder
+}
+
+kubebuilder() {
+    if ! mkdir -p ${KUBEBUILDER_ASSETS}; then
+      sudo mkdir -p ${KUBEBUILDER_ASSETS}
+      sudo chown $(whoami) ${KUBEBUILDER_ASSETS}
+    fi
+    arch=$(go env GOARCH)
+    ln -sf $(setup-envtest use -p path "${K8S_VERSION}" --arch="${arch}" --bin-dir="${KUBEBUILDER_ASSETS}")/* ${KUBEBUILDER_ASSETS}
+    find $KUBEBUILDER_ASSETS
+
+    # Install latest binaries for 1.25.x (contains CEL fix)
+    if [[ "${K8S_VERSION}" = "1.25.x" ]] && [[ "$OSTYPE" == "linux"* ]]; then
+        for binary in 'kube-apiserver' 'kubectl'; do
+            rm $KUBEBUILDER_ASSETS/$binary
+            wget -P $KUBEBUILDER_ASSETS dl.k8s.io/v1.25.16/bin/linux/${arch}/${binary}
+            chmod +x $KUBEBUILDER_ASSETS/$binary
+        done
+    fi
+}
+
+main "$@"

.github/workflows/presubmit.yaml

@@ -9,4 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
+    - uses: ./.github/actions/install-deps
+      with:
+        k8sVersion: 1.31
     - run: make presubmit

Makefile

@@ -14,4 +14,8 @@ verify: ##
 
 .PHONY: test
 test: ##
-	go test ./...
+	go test ./...
+
+.PHONY: toolchain
+toolchain: ##
+	./.github/toolchain.sh

singleton/controller.go

@@ -40,7 +40,7 @@ func Source() source.Source {
 }
 
 func ChannelSource[T client.Object](ctx context.Context, objectChan <-chan watch.Event) source.Source {
-	eventSource := make(chan event.GenericEvent, 1)
+	eventSource := make(chan event.GenericEvent, 1000)
 
 	go func(ctx context.Context, objectChan <-chan watch.Event, eventSource chan event.GenericEvent) {
 		for {