NE-2215: add CI step and presubmit for testing HAProxy 2.8

Add CI scaffolding for testing the non-default HAProxy version (2.8)
with the IngressControllerMultipleHAProxyVersions TechPreview feature gate:

- ingress-conf-haproxy-version step: writes an IngressController manifest
  to SHARED_DIR with the specified haproxyVersion, run before ipi-install
- e2e-aws-operator-haproxy28-techpreview CIO presubmit: optional operator
  e2e test with HAProxy 2.8 for validating CIO changes

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: gcs278

ci-operator/config/openshift/cluster-ingress-operator/openshift-cluster-ingress-operator-master.yaml

@@ -308,6 +308,27 @@ tests:
         requests:
           cpu: 100m
     workflow: ipi-aws
+- always_run: false
+  as: e2e-aws-operator-haproxy28-techpreview
+  optional: true
+  steps:
+    cluster_profile: openshift-org-aws
+    env:
+      FEATURE_SET: TechPreviewNoUpgrade
+      HAPROXY_VERSION: "2.8"
+    pre:
+    - chain: ipi-conf-aws
+    - ref: ingress-conf-haproxy-version
+    - chain: ipi-install
+    test:
+    - as: test
+      cli: latest
+      commands: make test-e2e
+      from: src
+      resources:
+        requests:
+          cpu: 100m
+    workflow: ipi-aws
 - always_run: false
   as: e2e-openstack-operator
   optional: true

ci-operator/step-registry/ingress/conf/haproxy-version/OWNERS

@@ -0,0 +1,10 @@
+approvers:
+- gcs278
+- jcmoraisjr
+- Miciah
+- candita
+reviewers:
+- gcs278
+- jcmoraisjr
+- Miciah
+- candita

ci-operator/step-registry/ingress/conf/haproxy-version/ingress-conf-haproxy-version-commands.sh

@@ -0,0 +1,33 @@
+#!/bin/bash
+
+set -o errexit
+set -o nounset
+set -o pipefail
+
+echo "Info: ingress-conf-haproxy-version running"
+echo "  HAPROXY_VERSION='${HAPROXY_VERSION:-<unset>}'"
+
+if [[ ! -d "${SHARED_DIR}" ]]; then
+  echo "Error: SHARED_DIR not set or doesn't exist"
+  exit 1
+fi
+
+if [[ -z "${HAPROXY_VERSION}" ]]; then
+  echo "Error: HAPROXY_VERSION must be set"
+  exit 1
+fi
+
+echo "Configuring default IngressController with HAProxy version: ${HAPROXY_VERSION}"
+
+cat > "${SHARED_DIR}/manifest_default-ingresscontroller.yaml" <<EOF
+apiVersion: operator.openshift.io/v1
+kind: IngressController
+metadata:
+  name: default
+  namespace: openshift-ingress-operator
+spec:
+  haproxyVersion: "${HAPROXY_VERSION}"
+EOF
+
+echo "Wrote IngressController manifest to ${SHARED_DIR}/manifest_default-ingresscontroller.yaml"
+cat "${SHARED_DIR}/manifest_default-ingresscontroller.yaml"

ci-operator/step-registry/ingress/conf/haproxy-version/ingress-conf-haproxy-version-ref.metadata.json

@@ -0,0 +1,11 @@
+{
+	"path": "ingress/conf/haproxy-version/ingress-conf-haproxy-version-ref.yaml",
+	"owners": {
+		"approvers": [
+			"gcs278",
+			"jcmoraisjr",
+			"Miciah",
+			"candita"
+		]
+	}
+}

ci-operator/step-registry/ingress/conf/haproxy-version/ingress-conf-haproxy-version-ref.yaml

@@ -0,0 +1,21 @@
+ref:
+  as: ingress-conf-haproxy-version
+  from: installer
+  commands: ingress-conf-haproxy-version-commands.sh
+  resources:
+    requests:
+      cpu: 10m
+      memory: 100Mi
+  env:
+  - name: HAPROXY_VERSION
+    default: ""
+    documentation: |-
+      The HAProxy version to configure on the default IngressController at
+      install time (e.g. "2.8"). This value is written into the
+      spec.haproxyVersion field of the IngressController manifest.
+  documentation: |-
+    Configures the default IngressController to use a specific HAProxy version
+    at install time by writing an IngressController manifest to SHARED_DIR.
+    The cluster must have the IngressControllerMultipleHAProxyVersions feature
+    gate enabled (TechPreviewNoUpgrade). This step should run before
+    ipi-install-install in the workflow.