setup-deploy-environment: add --channel and drop obsolete gateway step

The closing 'Next steps' hint was stable/release-specific and partly
wrong: it told operators to label a gateway node (forge already labels
the gwmain pool on both stable and nightly clusters) and to trigger
release-upgrade.yaml with a tag (nightly deploys a snapshot of main via
nightly.yaml on a schedule, not tags).

Add --channel stable|nightly (default stable, so stable output is
unchanged apart from removing the obsolete gateway-labeling step) and
print channel-appropriate trigger guidance. setup-nightly-cluster.sh
passes --channel nightly.

Author: plombardi89

hack/scripts/setup-deploy-environment.sh

@@ -31,6 +31,7 @@ export GH_PAGER=cat
 REPO="Azure/unbounded"
 MANAGE_CNI_PLUGIN="true"
 ASSUME_YES="false"
+DEPLOY_CHANNEL="stable"
 
 ENV_NAME=""
 KUBECONFIG_PATH=""
@@ -64,6 +65,7 @@ Required:
 
 Optional:
   --manage-cni-plugin BOOL   Whether unbounded manages the CNI (true|false). Default: true
+  --channel CHANNEL          Deploy channel for the "next steps" hint: stable|nightly. Default: stable
   --orca-azure-account NAME  Azure storage account for the Orca origin (enables Orca deploy)
   --orca-azure-container NAME Azure blob container for the Orca origin
   --orca-azure-endpoint URL  Azure blob endpoint (optional; blank => *.blob.core.windows.net)
@@ -101,6 +103,7 @@ while [[ $# -gt 0 ]]; do
         --site-node-cidr)      require_value "$1" "${2:-}"; SITE_NODE_CIDR="$2"; shift 2 ;;
         --site-pod-cidr)       require_value "$1" "${2:-}"; SITE_POD_CIDR="$2"; shift 2 ;;
         --manage-cni-plugin)   require_value "$1" "${2:-}"; MANAGE_CNI_PLUGIN="$2"; shift 2 ;;
+        --channel)             require_value "$1" "${2:-}"; DEPLOY_CHANNEL="$2"; shift 2 ;;
         --orca-azure-account)  require_value "$1" "${2:-}"; ORCA_AZURE_ACCOUNT="$2"; shift 2 ;;
         --orca-azure-container) require_value "$1" "${2:-}"; ORCA_AZURE_CONTAINER="$2"; shift 2 ;;
         --orca-azure-endpoint) require_value "$1" "${2:-}"; ORCA_AZURE_ENDPOINT="$2"; shift 2 ;;
@@ -140,6 +143,12 @@ case "$MANAGE_CNI_PLUGIN" in
     *) die "--manage-cni-plugin must be 'true' or 'false', got '$MANAGE_CNI_PLUGIN'" ;;
 esac
 
+# Validate deploy channel (only affects the "next steps" hint printed below).
+case "$DEPLOY_CHANNEL" in
+    stable|nightly) ;;
+    *) die "--channel must be 'stable' or 'nightly', got '$DEPLOY_CHANNEL'" ;;
+esac
+
 # Validate Orca config: account and container go together (endpoint is
 # optional). If neither is set, the Orca deploy job is left unconfigured.
 if [[ -n "$ORCA_AZURE_ACCOUNT" && -z "$ORCA_AZURE_CONTAINER" ]]; then
@@ -277,17 +286,34 @@ cat <<EOF
 
 Environment $ENV_NAME configured.
 
+EOF
+
+# Gateway nodes are labeled by forge's gateway pool, so no manual labeling
+# step is needed (both stable and nightly run on forge-built clusters). The
+# trigger differs per channel: stable deploys release tags via
+# release-upgrade.yaml; nightly deploys a snapshot of main via nightly.yaml.
+if [[ "$DEPLOY_CHANNEL" == "nightly" ]]; then
+    cat <<EOF
 Next steps:
 
-  1. Label at least one node as a gateway:
-       kubectl label node <node-name> \\
-         unbounded-cloud.io/unbounded-net-gateway=true --overwrite
+  1. Trigger the first install (run once per cluster):
+       gh workflow run nightly.yaml \\
+         --repo $REPO \\
+         -f force_init=true
+
+  2. Subsequent nightly snapshots of main deploy automatically to $ENV_NAME
+     at 06:00 UTC.
+EOF
+else
+    cat <<EOF
+Next steps:
 
-  2. Trigger the first install (run once per cluster):
+  1. Trigger the first install (run once per cluster):
        gh workflow run release-upgrade.yaml \\
          --repo $REPO \\
          -f tag=vX.Y.Z \\
          -f force_init=true
 
-  3. Subsequent published releases will deploy automatically to $ENV_NAME.
+  2. Subsequent published releases will deploy automatically to $ENV_NAME.
 EOF
+fi

hack/scripts/setup-nightly-cluster.sh

@@ -419,6 +419,7 @@ configure_environment() {
     --site-node-cidr "${SITE_NODE_CIDR}"
     --site-pod-cidr "${SITE_POD_CIDR}"
     --manage-cni-plugin "${MANAGE_CNI_PLUGIN}"
+    --channel nightly
     --orca-azure-account "${ORIGIN_ACCOUNT}"
     --orca-azure-container "${ORIGIN_CONTAINER}"
     --repo "${REPO}"