From 482255a7f16aa6c4c70e3a32c29dbb082ee4c584 Mon Sep 17 00:00:00 2001
From: Timofei Larkin <lllamnyp@gmail.com>
Date: Fri, 20 Mar 2026 11:15:50 +0300
Subject: [PATCH] [cozystack-scheduler] Publish SchedulingClass demo

## What this PR does

Publish the scripts used for running the Cozystack scheduler demo at the
community meetup on 19.03.2026.

### Release note

```release-note
[cozystack-scheduler] Add demo scripts to the cozystack-scheduler system
packages.
```
---
 .../examples/demo/00-helpers.sh               | 121 ++++++++++++++++
 .../examples/demo/01-scheduling-classes.sh    | 133 ++++++++++++++++++
 .../examples/demo/02-create-tenants.sh        | 121 ++++++++++++++++
 .../examples/demo/03-colocate-demo.sh         |  69 +++++++++
 .../examples/demo/04-colocate-second-redis.sh |  61 ++++++++
 .../examples/demo/05-colocate-cleanup.sh      |  24 ++++
 .../examples/demo/06-onepernode-demo.sh       |  92 ++++++++++++
 .../demo/07-onepernode-second-redis.sh        |  68 +++++++++
 .../examples/demo/08-onepernode-cleanup.sh    |  24 ++++
 .../examples/demo/09-spread-demo.sh           |  73 ++++++++++
 .../examples/demo/10-spread-cleanup.sh        |  24 ++++
 .../examples/demo/11-node2-demo.sh            |  94 +++++++++++++
 .../examples/demo/12-node2-cleanup.sh         |  23 +++
 .../examples/demo/13-teardown.sh              |  24 ++++
 14 files changed, 951 insertions(+)
 create mode 100755 packages/system/cozystack-scheduler/examples/demo/00-helpers.sh
 create mode 100755 packages/system/cozystack-scheduler/examples/demo/01-scheduling-classes.sh
 create mode 100755 packages/system/cozystack-scheduler/examples/demo/02-create-tenants.sh
 create mode 100755 packages/system/cozystack-scheduler/examples/demo/03-colocate-demo.sh
 create mode 100755 packages/system/cozystack-scheduler/examples/demo/04-colocate-second-redis.sh
 create mode 100755 packages/system/cozystack-scheduler/examples/demo/05-colocate-cleanup.sh
 create mode 100755 packages/system/cozystack-scheduler/examples/demo/06-onepernode-demo.sh
 create mode 100755 packages/system/cozystack-scheduler/examples/demo/07-onepernode-second-redis.sh
 create mode 100755 packages/system/cozystack-scheduler/examples/demo/08-onepernode-cleanup.sh
 create mode 100755 packages/system/cozystack-scheduler/examples/demo/09-spread-demo.sh
 create mode 100755 packages/system/cozystack-scheduler/examples/demo/10-spread-cleanup.sh
 create mode 100755 packages/system/cozystack-scheduler/examples/demo/11-node2-demo.sh
 create mode 100755 packages/system/cozystack-scheduler/examples/demo/12-node2-cleanup.sh
 create mode 100755 packages/system/cozystack-scheduler/examples/demo/13-teardown.sh

diff --git a/packages/system/cozystack-scheduler/examples/demo/00-helpers.sh b/packages/system/cozystack-scheduler/examples/demo/00-helpers.sh
new file mode 100755
index 00000000..1cd66446
--- /dev/null
+++ b/packages/system/cozystack-scheduler/examples/demo/00-helpers.sh
@@ -0,0 +1,121 @@
+#!/bin/bash
+# Helper functions for the scheduling classes demo
+# Source this file in other scripts: source "$(dirname "$0")/00-helpers.sh"
+
+# ANSI color codes
+export RED='\033[0;31m'
+export GREEN='\033[0;32m'
+export YELLOW='\033[1;33m'
+export BLUE='\033[0;34m'
+export MAGENTA='\033[0;35m'
+export CYAN='\033[0;36m'
+export WHITE='\033[1;37m'
+export NC='\033[0m' # No Color
+export BOLD='\033[1m'
+
+log_info() {
+    echo -e "${BLUE}ℹ${NC} $*" >&2
+}
+
+log_success() {
+    echo -e "${GREEN}✔${NC} $*" >&2
+}
+
+log_warning() {
+    echo -e "${YELLOW}⚠${NC} $*" >&2
+}
+
+log_error() {
+    echo -e "${RED}✖${NC} $*" >&2
+}
+
+log_step() {
+    echo -e "\n${MAGENTA}${BOLD}▶ $*${NC}" >&2
+}
+
+log_command() {
+    echo -e "${WHITE}  \$ $*${NC}" >&2
+}
+
+separator() {
+    echo -e "\n${CYAN}────────────────────────────────────────────────────────────${NC}\n" >&2
+}
+
+print_header() {
+    local title="$1"
+    echo -e "\n${MAGENTA}${BOLD}╔════════════════════════════════════════════════════════════╗${NC}" >&2
+    echo -e "${MAGENTA}${BOLD}║${NC} ${WHITE}${BOLD}$title${NC}" >&2
+    echo -e "${MAGENTA}${BOLD}╚════════════════════════════════════════════════════════════╝${NC}\n" >&2
+}
+
+# Display a YAML manifest with syntax highlighting (just colored output)
+show_manifest() {
+    echo -e "${YELLOW}$1${NC}" >&2
+}
+
+# Wait for user to press any key
+pause() {
+    echo -e "\n${CYAN}Press any key to continue...${NC}" >&2
+    read -rsn1
+}
+
+# Wait for pods to appear and stabilize
+wait_for_pods() {
+    local namespace="$1"
+    local label="${2:-}"
+    local timeout="${3:-120}"
+    local elapsed=0
+
+    log_info "Waiting for pods in $namespace..."
+    while true; do
+        local count
+        if [[ -n "$label" ]]; then
+            count=$(kubectl get pods -n "$namespace" -l "$label" --no-headers 2>/dev/null | wc -l)
+        else
+            count=$(kubectl get pods -n "$namespace" --no-headers 2>/dev/null | wc -l)
+        fi
+        if [[ "$count" -gt 0 ]]; then
+            break
+        fi
+        if [[ $elapsed -ge $timeout ]]; then
+            log_warning "Timed out waiting for pods"
+            return 1
+        fi
+        sleep 2
+        elapsed=$((elapsed + 2))
+    done
+    # Give pods a moment to get node assignments
+    sleep 3
+}
+
+# Show pods with node placement
+show_pods() {
+    local namespace="$1"
+    echo "" >&2
+    kubectl get pods -n "$namespace" -o wide 2>&1 >&2
+    echo "" >&2
+}
+
+# Wait for a Redis resource to be ready (HelmRelease applied)
+wait_for_redis_ready() {
+    local namespace="$1"
+    local name="$2"
+    local timeout="${3:-180}"
+    local elapsed=0
+
+    log_info "Waiting for Redis $name in $namespace to become ready..."
+    while true; do
+        local phase
+        phase=$(kubectl get redis "$name" -n "$namespace" -o jsonpath='{.status.conditions[0].status}' 2>/dev/null || echo "")
+        if [[ "$phase" == "True" ]]; then
+            log_success "Redis $name is ready"
+            break
+        fi
+        if [[ $elapsed -ge $timeout ]]; then
+            log_warning "Timed out waiting for Redis to be ready, continuing anyway..."
+            break
+        fi
+        sleep 5
+        elapsed=$((elapsed + 5))
+    done
+}
diff --git a/packages/system/cozystack-scheduler/examples/demo/01-scheduling-classes.sh b/packages/system/cozystack-scheduler/examples/demo/01-scheduling-classes.sh
new file mode 100755
index 00000000..2ef6e977
--- /dev/null
+++ b/packages/system/cozystack-scheduler/examples/demo/01-scheduling-classes.sh
@@ -0,0 +1,133 @@
+#!/bin/bash
+# Script 01: Create SchedulingClasses
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/00-helpers.sh"
+
+print_header "Step 1: Create SchedulingClasses"
+
+# --- pin-to-node2 ---
+log_step "SchedulingClass: pin-to-node2"
+log_info "All pods will always be scheduled to node2."
+
+show_manifest "apiVersion: cozystack.io/v1alpha1
+kind: SchedulingClass
+metadata:
+  name: pin-to-node2
+spec:
+  nodeSelector:
+    kubernetes.io/hostname: node2"
+
+pause
+
+kubectl apply -f - <<'EOF'
+apiVersion: cozystack.io/v1alpha1
+kind: SchedulingClass
+metadata:
+  name: pin-to-node2
+spec:
+  nodeSelector:
+    kubernetes.io/hostname: node2
+EOF
+
+log_success "Created SchedulingClass pin-to-node2"
+
+separator
+
+# --- one-per-node ---
+log_step "SchedulingClass: one-per-node"
+log_info "Pods of the same application will never share a node."
+
+show_manifest "apiVersion: cozystack.io/v1alpha1
+kind: SchedulingClass
+metadata:
+  name: one-per-node
+spec:
+  podAntiAffinity:
+    requiredDuringSchedulingIgnoredDuringExecution:
+    - topologyKey: kubernetes.io/hostname"
+
+pause
+
+kubectl apply -f - <<'EOF'
+apiVersion: cozystack.io/v1alpha1
+kind: SchedulingClass
+metadata:
+  name: one-per-node
+spec:
+  podAntiAffinity:
+    requiredDuringSchedulingIgnoredDuringExecution:
+    - topologyKey: kubernetes.io/hostname
+EOF
+
+log_success "Created SchedulingClass one-per-node"
+
+separator
+
+# --- spread-evenly ---
+log_step "SchedulingClass: spread-evenly"
+log_info "Pods will be spread evenly across nodes (maxSkew=1)."
+
+show_manifest "apiVersion: cozystack.io/v1alpha1
+kind: SchedulingClass
+metadata:
+  name: spread-evenly
+spec:
+  topologySpreadConstraints:
+  - maxSkew: 1
+    topologyKey: kubernetes.io/hostname
+    whenUnsatisfiable: DoNotSchedule"
+
+pause
+
+kubectl apply -f - <<'EOF'
+apiVersion: cozystack.io/v1alpha1
+kind: SchedulingClass
+metadata:
+  name: spread-evenly
+spec:
+  topologySpreadConstraints:
+  - maxSkew: 1
+    topologyKey: kubernetes.io/hostname
+    whenUnsatisfiable: DoNotSchedule
+EOF
+
+log_success "Created SchedulingClass spread-evenly"
+
+separator
+
+# --- colocate ---
+log_step "SchedulingClass: colocate"
+log_info "All pods of the same application will land on the same node."
+
+show_manifest "apiVersion: cozystack.io/v1alpha1
+kind: SchedulingClass
+metadata:
+  name: colocate
+spec:
+  podAffinity:
+    requiredDuringSchedulingIgnoredDuringExecution:
+    - topologyKey: kubernetes.io/hostname"
+
+pause
+
+kubectl apply -f - <<'EOF'
+apiVersion: cozystack.io/v1alpha1
+kind: SchedulingClass
+metadata:
+  name: colocate
+spec:
+  podAffinity:
+    requiredDuringSchedulingIgnoredDuringExecution:
+    - topologyKey: kubernetes.io/hostname
+EOF
+
+log_success "Created SchedulingClass colocate"
+
+separator
+log_success "All SchedulingClasses created."
+log_command "kubectl get schedulingclasses"
+kubectl get schedulingclasses >&2
+
+echo -e "\n${GREEN}${BOLD}Next step:${NC} ./02-create-tenants.sh"
diff --git a/packages/system/cozystack-scheduler/examples/demo/02-create-tenants.sh b/packages/system/cozystack-scheduler/examples/demo/02-create-tenants.sh
new file mode 100755
index 00000000..7a9d6b9d
--- /dev/null
+++ b/packages/system/cozystack-scheduler/examples/demo/02-create-tenants.sh
@@ -0,0 +1,121 @@
+#!/bin/bash
+# Script 02: Create tenants, one per scheduling class
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/00-helpers.sh"
+
+print_header "Step 2: Create Tenants"
+
+# --- tenant colocate ---
+log_step "Tenant: colocate (schedulingClass: colocate)"
+
+show_manifest "apiVersion: apps.cozystack.io/v1alpha1
+kind: Tenant
+metadata:
+  name: colocate
+  namespace: tenant-root
+spec:
+  schedulingClass: colocate"
+
+pause
+
+kubectl apply -f - <<'EOF'
+apiVersion: apps.cozystack.io/v1alpha1
+kind: Tenant
+metadata:
+  name: colocate
+  namespace: tenant-root
+spec:
+  schedulingClass: colocate
+EOF
+
+log_success "Created tenant colocate"
+
+separator
+
+# --- tenant onepernode ---
+log_step "Tenant: onepernode (schedulingClass: one-per-node)"
+
+show_manifest "apiVersion: apps.cozystack.io/v1alpha1
+kind: Tenant
+metadata:
+  name: onepernode
+  namespace: tenant-root
+spec:
+  schedulingClass: one-per-node"
+
+pause
+
+kubectl apply -f - <<'EOF'
+apiVersion: apps.cozystack.io/v1alpha1
+kind: Tenant
+metadata:
+  name: onepernode
+  namespace: tenant-root
+spec:
+  schedulingClass: one-per-node
+EOF
+
+log_success "Created tenant onepernode"
+
+separator
+
+# --- tenant spread ---
+log_step "Tenant: spread (schedulingClass: spread-evenly)"
+
+show_manifest "apiVersion: apps.cozystack.io/v1alpha1
+kind: Tenant
+metadata:
+  name: spread
+  namespace: tenant-root
+spec:
+  schedulingClass: spread-evenly"
+
+pause
+
+kubectl apply -f - <<'EOF'
+apiVersion: apps.cozystack.io/v1alpha1
+kind: Tenant
+metadata:
+  name: spread
+  namespace: tenant-root
+spec:
+  schedulingClass: spread-evenly
+EOF
+
+log_success "Created tenant spread"
+
+separator
+
+# --- tenant node2 ---
+log_step "Tenant: node2 (schedulingClass: pin-to-node2)"
+
+show_manifest "apiVersion: apps.cozystack.io/v1alpha1
+kind: Tenant
+metadata:
+  name: node2
+  namespace: tenant-root
+spec:
+  schedulingClass: pin-to-node2"
+
+pause
+
+kubectl apply -f - <<'EOF'
+apiVersion: apps.cozystack.io/v1alpha1
+kind: Tenant
+metadata:
+  name: node2
+  namespace: tenant-root
+spec:
+  schedulingClass: pin-to-node2
+EOF
+
+log_success "Created tenant node2"
+
+separator
+log_success "All tenants created."
+log_command "kubectl get tenants -n tenant-root"
+kubectl get tenants -n tenant-root >&2
+
+echo -e "\n${GREEN}${BOLD}Next step:${NC} ./03-colocate-demo.sh"
diff --git a/packages/system/cozystack-scheduler/examples/demo/03-colocate-demo.sh b/packages/system/cozystack-scheduler/examples/demo/03-colocate-demo.sh
new file mode 100755
index 00000000..9019a00a
--- /dev/null
+++ b/packages/system/cozystack-scheduler/examples/demo/03-colocate-demo.sh
@@ -0,0 +1,69 @@
+#!/bin/bash
+# Script 03: Colocate demo - all pods of a Redis land on the same node
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/00-helpers.sh"
+
+NAMESPACE="tenant-colocate"
+REDIS_NAME="redis-demo"
+
+print_header "Step 3: Colocate Demo"
+
+log_step "Creating Redis in $NAMESPACE (1 replica + 3 sentinels)"
+
+show_manifest "apiVersion: apps.cozystack.io/v1alpha1
+kind: Redis
+metadata:
+  name: $REDIS_NAME
+  namespace: $NAMESPACE
+spec:
+  replicas: 1
+  storageClass: local
+  resourcesPreset: nano
+  authEnabled: false"
+
+pause
+
+kubectl apply -f - <<EOF
+apiVersion: apps.cozystack.io/v1alpha1
+kind: Redis
+metadata:
+  name: $REDIS_NAME
+  namespace: $NAMESPACE
+spec:
+  replicas: 1
+  storageClass: local
+  resourcesPreset: nano
+  authEnabled: false
+EOF
+
+log_success "Redis $REDIS_NAME created"
+
+separator
+
+log_step "Waiting for pods to be scheduled..."
+wait_for_redis_ready "$NAMESPACE" "$REDIS_NAME"
+wait_for_pods "$NAMESPACE"
+
+log_step "All pods should be on the SAME node:"
+show_pods "$NAMESPACE"
+
+pause
+
+separator
+
+log_step "Scaling up replicas to 9..."
+log_command "kubectl patch redis $REDIS_NAME -n $NAMESPACE --type=merge -p '{\"spec\":{\"replicas\":9}}'"
+
+kubectl patch redis "$REDIS_NAME" -n "$NAMESPACE" --type=merge -p '{"spec":{"replicas":9}}'
+
+log_info "Waiting for new pods..."
+sleep 15
+
+log_step "All pods (storage + sentinels) are still on the same node:"
+show_pods "$NAMESPACE"
+
+separator
+log_success "Colocate demo complete. All pods landed on one node."
+echo -e "\n${GREEN}${BOLD}Next step:${NC} ./04-colocate-second-redis.sh"
diff --git a/packages/system/cozystack-scheduler/examples/demo/04-colocate-second-redis.sh b/packages/system/cozystack-scheduler/examples/demo/04-colocate-second-redis.sh
new file mode 100755
index 00000000..eea8c6ff
--- /dev/null
+++ b/packages/system/cozystack-scheduler/examples/demo/04-colocate-second-redis.sh
@@ -0,0 +1,61 @@
+#!/bin/bash
+# Script 04: Second Redis in colocate tenant - shows cross-app independence
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/00-helpers.sh"
+
+NAMESPACE="tenant-colocate"
+REDIS_NAME="redis-demo2"
+
+print_header "Step 4: Colocate - Second Redis (cross-app independence)"
+
+log_step "Cleaning up $REDIS_NAME if it already exists..."
+kubectl delete redis "$REDIS_NAME" -n "$NAMESPACE" --ignore-not-found >&2
+sleep 3
+
+separator
+
+log_step "Creating a second Redis in $NAMESPACE"
+log_info "This Redis will colocate its own pods together,"
+log_info "but may land on a DIFFERENT node than the first Redis."
+
+show_manifest "apiVersion: apps.cozystack.io/v1alpha1
+kind: Redis
+metadata:
+  name: $REDIS_NAME
+  namespace: $NAMESPACE
+spec:
+  replicas: 1
+  storageClass: local
+  resourcesPreset: nano
+  authEnabled: false"
+
+pause
+
+kubectl apply -f - <<EOF
+apiVersion: apps.cozystack.io/v1alpha1
+kind: Redis
+metadata:
+  name: $REDIS_NAME
+  namespace: $NAMESPACE
+spec:
+  replicas: 1
+  storageClass: local
+  resourcesPreset: nano
+  authEnabled: false
+EOF
+
+log_success "Redis $REDIS_NAME created"
+
+log_step "Waiting for pods to be scheduled..."
+wait_for_redis_ready "$NAMESPACE" "$REDIS_NAME"
+wait_for_pods "$NAMESPACE"
+
+log_step "Pod placement for both Redis instances:"
+log_info "Each Redis colocates its own pods, but the two Redises are independent."
+show_pods "$NAMESPACE"
+
+separator
+log_success "Second Redis demo complete."
+echo -e "\n${GREEN}${BOLD}Next step:${NC} ./05-colocate-cleanup.sh"
diff --git a/packages/system/cozystack-scheduler/examples/demo/05-colocate-cleanup.sh b/packages/system/cozystack-scheduler/examples/demo/05-colocate-cleanup.sh
new file mode 100755
index 00000000..8baca4a4
--- /dev/null
+++ b/packages/system/cozystack-scheduler/examples/demo/05-colocate-cleanup.sh
@@ -0,0 +1,24 @@
+#!/bin/bash
+# Script 05: Clean up Redis instances in tenant-colocate
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/00-helpers.sh"
+
+NAMESPACE="tenant-colocate"
+
+print_header "Step 5: Clean up tenant-colocate"
+
+log_step "Deleting all Redis instances in $NAMESPACE..."
+
+kubectl delete redis --all -n "$NAMESPACE" --ignore-not-found >&2
+
+log_info "Waiting for pods to terminate..."
+sleep 10
+
+log_step "Remaining pods:"
+show_pods "$NAMESPACE"
+
+separator
+log_success "Cleanup complete."
+echo -e "\n${GREEN}${BOLD}Next step:${NC} ./06-onepernode-demo.sh"
diff --git a/packages/system/cozystack-scheduler/examples/demo/06-onepernode-demo.sh b/packages/system/cozystack-scheduler/examples/demo/06-onepernode-demo.sh
new file mode 100755
index 00000000..f656422a
--- /dev/null
+++ b/packages/system/cozystack-scheduler/examples/demo/06-onepernode-demo.sh
@@ -0,0 +1,92 @@
+#!/bin/bash
+# Script 06: One-per-node demo - anti-affinity prevents pods on the same node
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/00-helpers.sh"
+
+NAMESPACE="tenant-onepernode"
+REDIS_NAME="redis-demo"
+
+print_header "Step 6: One-per-node Demo"
+
+log_step "Creating Redis in $NAMESPACE (1 replica)"
+log_info "We'll also reduce sentinels to 2 (1 storage + 2 sentinels = 3 pods for 3 nodes)."
+
+show_manifest "apiVersion: apps.cozystack.io/v1alpha1
+kind: Redis
+metadata:
+  name: $REDIS_NAME
+  namespace: $NAMESPACE
+spec:
+  replicas: 1
+  storageClass: local
+  resourcesPreset: nano
+  authEnabled: false"
+
+pause
+
+kubectl apply -f - <<EOF
+apiVersion: apps.cozystack.io/v1alpha1
+kind: Redis
+metadata:
+  name: $REDIS_NAME
+  namespace: $NAMESPACE
+spec:
+  replicas: 1
+  storageClass: local
+  resourcesPreset: nano
+  authEnabled: false
+EOF
+
+log_success "Redis $REDIS_NAME created"
+
+log_info "Waiting for RedisFailover to appear..."
+sleep 10
+
+log_step "Patching RedisFailover to use 2 sentinels instead of 3"
+log_info "With 3 nodes and anti-affinity, 1 storage + 3 sentinels = 4 pods won't fit."
+log_command "kubectl patch rf $REDIS_NAME -n $NAMESPACE --type=merge -p '{\"spec\":{\"sentinel\":{\"replicas\":2}}}'"
+
+kubectl patch rf redis-"$REDIS_NAME" -n "$NAMESPACE" --type=merge -p '{"spec":{"sentinel":{"replicas":2}}}'
+
+log_info "Waiting for pods to be scheduled..."
+wait_for_pods "$NAMESPACE"
+sleep 5
+
+log_step "Each pod is on a different node (1 storage + 2 sentinels on 3 nodes):"
+show_pods "$NAMESPACE"
+
+pause
+
+separator
+
+log_step "Scaling up to 3 replicas..."
+log_command "kubectl patch redis $REDIS_NAME -n $NAMESPACE --type=merge -p '{\"spec\":{\"replicas\":3}}'"
+
+kubectl patch redis "$REDIS_NAME" -n "$NAMESPACE" --type=merge -p '{"spec":{"replicas":3}}'
+
+log_info "Waiting for new pods..."
+sleep 15
+
+log_step "Some pods should now be Pending (anti-affinity prevents scheduling):"
+show_pods "$NAMESPACE"
+
+pause
+
+separator
+
+log_step "Describing a Pending pod to see why it can't be scheduled..."
+PENDING_POD=$(kubectl get pods -n "$NAMESPACE" --field-selector=status.phase=Pending -o jsonpath='{.items[0].metadata.name}' 2>/dev/null || echo "")
+
+if [[ -n "$PENDING_POD" ]]; then
+    log_command "kubectl describe pod $PENDING_POD -n $NAMESPACE | tail -10"
+    kubectl describe pod "$PENDING_POD" -n "$NAMESPACE" 2>&1 | tail -10 >&2
+else
+    log_warning "No Pending pods found (pods may still be initializing)."
+    log_command "kubectl get pods -n $NAMESPACE -o wide"
+fi
+
+separator
+log_success "One-per-node demo complete. Anti-affinity prevents co-scheduling."
+echo -e "\n${GREEN}${BOLD}Next step:${NC} ./07-onepernode-second-redis.sh"
diff --git a/packages/system/cozystack-scheduler/examples/demo/07-onepernode-second-redis.sh b/packages/system/cozystack-scheduler/examples/demo/07-onepernode-second-redis.sh
new file mode 100755
index 00000000..e86a07e8
--- /dev/null
+++ b/packages/system/cozystack-scheduler/examples/demo/07-onepernode-second-redis.sh
@@ -0,0 +1,68 @@
+#!/bin/bash
+# Script 07: Second Redis in one-per-node tenant - shows cross-app independence
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/00-helpers.sh"
+
+NAMESPACE="tenant-onepernode"
+REDIS_NAME="redis-demo2"
+
+print_header "Step 7: One-per-node - Second Redis (cross-app independence)"
+
+log_step "Cleaning up $REDIS_NAME if it already exists..."
+kubectl delete redis "$REDIS_NAME" -n "$NAMESPACE" --ignore-not-found >&2
+sleep 3
+
+separator
+
+log_step "Creating a second Redis in $NAMESPACE"
+log_info "Anti-affinity only applies WITHIN the same application."
+log_info "This second Redis has no anti-affinity against the first one."
+
+show_manifest "apiVersion: apps.cozystack.io/v1alpha1
+kind: Redis
+metadata:
+  name: $REDIS_NAME
+  namespace: $NAMESPACE
+spec:
+  replicas: 1
+  storageClass: local
+  resourcesPreset: nano
+  authEnabled: false"
+
+pause
+
+kubectl apply -f - <<EOF
+apiVersion: apps.cozystack.io/v1alpha1
+kind: Redis
+metadata:
+  name: $REDIS_NAME
+  namespace: $NAMESPACE
+spec:
+  replicas: 1
+  storageClass: local
+  resourcesPreset: nano
+  authEnabled: false
+EOF
+
+log_success "Redis $REDIS_NAME created"
+
+log_info "Waiting for RedisFailover to appear..."
+sleep 10
+
+log_step "Patching sentinels to 2 for the second Redis as well"
+kubectl patch rf redis-"$REDIS_NAME" -n "$NAMESPACE" --type=merge -p '{"spec":{"sentinel":{"replicas":2}}}'
+
+log_info "Waiting for pods to be scheduled..."
+wait_for_pods "$NAMESPACE"
+sleep 5
+
+log_step "Pod placement for both Redis instances:"
+log_info "Each Redis spreads its own pods one-per-node independently."
+log_info "The two Redises CAN share nodes — anti-affinity is per-application."
+show_pods "$NAMESPACE"
+
+separator
+log_success "Second Redis demo complete."
+echo -e "\n${GREEN}${BOLD}Next step:${NC} ./08-onepernode-cleanup.sh"
diff --git a/packages/system/cozystack-scheduler/examples/demo/08-onepernode-cleanup.sh b/packages/system/cozystack-scheduler/examples/demo/08-onepernode-cleanup.sh
new file mode 100755
index 00000000..071a5ff2
--- /dev/null
+++ b/packages/system/cozystack-scheduler/examples/demo/08-onepernode-cleanup.sh
@@ -0,0 +1,24 @@
+#!/bin/bash
+# Script 08: Clean up Redis instances in tenant-onepernode
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/00-helpers.sh"
+
+NAMESPACE="tenant-onepernode"
+
+print_header "Step 8: Clean up tenant-onepernode"
+
+log_step "Deleting all Redis instances in $NAMESPACE..."
+
+kubectl delete redis --all -n "$NAMESPACE" --ignore-not-found >&2
+
+log_info "Waiting for pods to terminate..."
+sleep 10
+
+log_step "Remaining pods:"
+show_pods "$NAMESPACE"
+
+separator
+log_success "Cleanup complete."
+echo -e "\n${GREEN}${BOLD}Next step:${NC} ./09-spread-demo.sh"
diff --git a/packages/system/cozystack-scheduler/examples/demo/09-spread-demo.sh b/packages/system/cozystack-scheduler/examples/demo/09-spread-demo.sh
new file mode 100755
index 00000000..91d3b35f
--- /dev/null
+++ b/packages/system/cozystack-scheduler/examples/demo/09-spread-demo.sh
@@ -0,0 +1,73 @@
+#!/bin/bash
+# Script 09: Spread-evenly demo - topology spread constraints
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/00-helpers.sh"
+
+NAMESPACE="tenant-spread"
+REDIS_NAME="redis-demo"
+
+print_header "Step 9: Spread-evenly Demo"
+
+log_step "Creating Redis in $NAMESPACE (1 replica)"
+
+show_manifest "apiVersion: apps.cozystack.io/v1alpha1
+kind: Redis
+metadata:
+  name: $REDIS_NAME
+  namespace: $NAMESPACE
+spec:
+  replicas: 1
+  storageClass: local
+  resourcesPreset: nano
+  authEnabled: false"
+
+pause
+
+kubectl apply -f - <<EOF
+apiVersion: apps.cozystack.io/v1alpha1
+kind: Redis
+metadata:
+  name: $REDIS_NAME
+  namespace: $NAMESPACE
+spec:
+  replicas: 1
+  storageClass: local
+  resourcesPreset: nano
+  authEnabled: false
+EOF
+
+log_success "Redis $REDIS_NAME created"
+
+log_info "Waiting for pods to be scheduled..."
+wait_for_redis_ready "$NAMESPACE" "$REDIS_NAME"
+wait_for_pods "$NAMESPACE"
+
+log_step "Initial pod distribution (1 storage + 3 sentinels):"
+show_pods "$NAMESPACE"
+
+pause
+
+separator
+
+log_step "Scaling up to 9 replicas..."
+log_command "kubectl patch redis $REDIS_NAME -n $NAMESPACE --type=merge -p '{\"spec\":{\"replicas\":9}}'"
+
+kubectl patch redis "$REDIS_NAME" -n "$NAMESPACE" --type=merge -p '{"spec":{"replicas":9}}'
+
+log_info "Waiting for new pods..."
+sleep 20
+
+log_step "Pods should be evenly distributed across all nodes (maxSkew=1):"
+show_pods "$NAMESPACE"
+
+separator
+
+log_step "Pod count per node:"
+kubectl get pods -n "$NAMESPACE" -o wide --no-headers 2>/dev/null \
+    | awk '{print $7}' | sort | uniq -c | sort -rn >&2
+
+separator
+log_success "Spread-evenly demo complete. Pods are balanced across nodes."
+echo -e "\n${GREEN}${BOLD}Next step:${NC} ./10-spread-cleanup.sh"
diff --git a/packages/system/cozystack-scheduler/examples/demo/10-spread-cleanup.sh b/packages/system/cozystack-scheduler/examples/demo/10-spread-cleanup.sh
new file mode 100755
index 00000000..9049aff5
--- /dev/null
+++ b/packages/system/cozystack-scheduler/examples/demo/10-spread-cleanup.sh
@@ -0,0 +1,24 @@
+#!/bin/bash
+# Script 10: Clean up Redis instances in tenant-spread
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/00-helpers.sh"
+
+NAMESPACE="tenant-spread"
+
+print_header "Step 10: Clean up tenant-spread"
+
+log_step "Deleting all Redis instances in $NAMESPACE..."
+
+kubectl delete redis --all -n "$NAMESPACE" --ignore-not-found >&2
+
+log_info "Waiting for pods to terminate..."
+sleep 10
+
+log_step "Remaining pods:"
+show_pods "$NAMESPACE"
+
+separator
+log_success "Cleanup complete."
+echo -e "\n${GREEN}${BOLD}Next step:${NC} ./11-node2-demo.sh"
diff --git a/packages/system/cozystack-scheduler/examples/demo/11-node2-demo.sh b/packages/system/cozystack-scheduler/examples/demo/11-node2-demo.sh
new file mode 100755
index 00000000..a3ae32ec
--- /dev/null
+++ b/packages/system/cozystack-scheduler/examples/demo/11-node2-demo.sh
@@ -0,0 +1,94 @@
+#!/bin/bash
+# Script 11: Pin-to-node2 demo - all pods on a specific node
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/00-helpers.sh"
+
+NAMESPACE="tenant-node2"
+REDIS1="redis-demo"
+REDIS2="redis-demo2"
+
+print_header "Step 11: Pin-to-node2 Demo"
+
+log_step "Creating first Redis in $NAMESPACE"
+
+show_manifest "apiVersion: apps.cozystack.io/v1alpha1
+kind: Redis
+metadata:
+  name: $REDIS1
+  namespace: $NAMESPACE
+spec:
+  replicas: 1
+  storageClass: local
+  resourcesPreset: nano
+  authEnabled: false"
+
+pause
+
+kubectl apply -f - <<EOF
+apiVersion: apps.cozystack.io/v1alpha1
+kind: Redis
+metadata:
+  name: $REDIS1
+  namespace: $NAMESPACE
+spec:
+  replicas: 1
+  storageClass: local
+  resourcesPreset: nano
+  authEnabled: false
+EOF
+
+log_success "Redis $REDIS1 created"
+
+log_info "Waiting for pods to be scheduled..."
+wait_for_redis_ready "$NAMESPACE" "$REDIS1"
+wait_for_pods "$NAMESPACE"
+
+log_step "All pods should be on node2:"
+show_pods "$NAMESPACE"
+
+pause
+
+separator
+
+log_step "Creating a second Redis in $NAMESPACE"
+
+show_manifest "apiVersion: apps.cozystack.io/v1alpha1
+kind: Redis
+metadata:
+  name: $REDIS2
+  namespace: $NAMESPACE
+spec:
+  replicas: 1
+  storageClass: local
+  resourcesPreset: nano
+  authEnabled: false"
+
+pause
+
+kubectl apply -f - <<EOF
+apiVersion: apps.cozystack.io/v1alpha1
+kind: Redis
+metadata:
+  name: $REDIS2
+  namespace: $NAMESPACE
+spec:
+  replicas: 1
+  storageClass: local
+  resourcesPreset: nano
+  authEnabled: false
+EOF
+
+log_success "Redis $REDIS2 created"
+
+log_info "Waiting for pods to be scheduled..."
+wait_for_redis_ready "$NAMESPACE" "$REDIS2"
+wait_for_pods "$NAMESPACE"
+
+log_step "Both Redis instances — all pods pinned to node2:"
+show_pods "$NAMESPACE"
+
+separator
+log_success "Pin-to-node2 demo complete."
+echo -e "\n${GREEN}${BOLD}Next step:${NC} ./12-node2-cleanup.sh"
diff --git a/packages/system/cozystack-scheduler/examples/demo/12-node2-cleanup.sh b/packages/system/cozystack-scheduler/examples/demo/12-node2-cleanup.sh
new file mode 100755
index 00000000..ed48988d
--- /dev/null
+++ b/packages/system/cozystack-scheduler/examples/demo/12-node2-cleanup.sh
@@ -0,0 +1,23 @@
+#!/bin/bash
+# Script 12: Clean up Redis instances in tenant-node2
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/00-helpers.sh"
+
+NAMESPACE="tenant-node2"
+
+print_header "Step 12: Clean up tenant-node2"
+
+log_step "Deleting all Redis instances in $NAMESPACE..."
+
+kubectl delete redis --all -n "$NAMESPACE" --ignore-not-found >&2
+
+log_info "Waiting for pods to terminate..."
+sleep 10
+
+log_step "Remaining pods:"
+show_pods "$NAMESPACE"
+
+separator
+log_success "Cleanup complete. Demo finished!"
diff --git a/packages/system/cozystack-scheduler/examples/demo/13-teardown.sh b/packages/system/cozystack-scheduler/examples/demo/13-teardown.sh
new file mode 100755
index 00000000..529df7b2
--- /dev/null
+++ b/packages/system/cozystack-scheduler/examples/demo/13-teardown.sh
@@ -0,0 +1,24 @@
+#!/bin/bash
+# Script 13: Tear down all tenants and scheduling classes
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/00-helpers.sh"
+
+print_header "Teardown: Remove tenants and scheduling classes"
+
+log_step "Deleting tenants..."
+for t in colocate onepernode spread node2; do
+    kubectl delete tenant "$t" -n tenant-root --ignore-not-found >&2
+done
+
+log_info "Waiting for tenant namespaces to be cleaned up..."
+sleep 15
+
+log_step "Deleting scheduling classes..."
+for sc in colocate one-per-node spread-evenly pin-to-node2; do
+    kubectl delete schedulingclass "$sc" --ignore-not-found >&2
+done
+
+separator
+log_success "Teardown complete."