chore(nodepool|instancepool): allow downsizing to 0

[zyegfryed]

Description

Align the command line with the documentation, for which both NodePool 1 and InstancePool 2 are able to scale to 0.

Checklist

(For exoscale contributors)

• Changelog updated (under Unreleased block)
• Testing

Testing

Tried the work against SKS Nodepool to scale it down to 0:

➜ exo compute sks create cluster-sc162955-001 --service-level starter
 ✔ Creating SKS cluster "cluster-sc162955-001"... 1m19s
┼───────────────────┼──────────────────────────────────────────────────────────┼
│    SKS CLUSTER    │                                                          │
┼───────────────────┼──────────────────────────────────────────────────────────┼
│ ID                │ bd6def1f-8cf1-4ad1-9d6e-a472ff7c1c3f                     │
│ Name              │ cluster-sc162955-001                                     │
│ Description       │                                                          │
│ Zone              │ ch-gva-2                                                 │
│ Creation Date     │ 2026-01-26 15:33:09 +0000 UTC                            │
│ Auto-upgrade      │ false                                                    │
│ Enable kube-proxy │ true                                                     │
│ Endpoint          │ bd6def1f-8cf1-4ad1-9d6e-a472ff7c1c3f.sks-ch-gva-2.exo.io │
│ Version           │ 1.35.0                                                   │
│ Service Level     │ starter                                                  │
│ CNI               │ calico                                                   │
│ Add-Ons           │ exoscale-cloud-controller                                │
│                   │ metrics-server                                           │
│ Audit Enabled     │ false                                                    │
│ Feature Gates     │                                                          │
│ State             │ running                                                  │
│ Labels            │ n/a                                                      │
│ Nodepools         │ n/a                                                      │
┼───────────────────┼──────────────────────────────────────────────────────────┼
➜ exo compute sks nodepool add cluster-sc162955-001 nodepool-sc162955-001
 ✔ Adding Nodepool "nodepool-sc162955-001"... 39s
┼─────────────────────────┼──────────────────────────────────────┼
│      SKS NODEPOOL       │                                      │
┼─────────────────────────┼──────────────────────────────────────┼
│ ID                      │ ee79ffe1-29b8-4459-ba83-46260acdc90a │
│ Name                    │ nodepool-sc162955-001                │
│ Description             │                                      │
│ Creation Date           │ 2026-01-26 15:41:25 +0000 UTC        │
│ Instance Pool ID        │ 723bcbc6-f3ef-47a8-9c3f-5cd7ac6c56a6 │
│ Instance Prefix         │ pool                                 │
│ Instance Type           │ standard.medium                      │
│ Template                │ sks-node-1.35.0-standard             │
│ Disk Size               │ 50                                   │
│ IPv6                    │ false                                │
│ Anti Affinity Groups    │ n/a                                  │
│ Security Groups         │ n/a                                  │
│ Private Networks        │ n/a                                  │
│ Version                 │ 1.35.0                               │
│ Size                    │ 2                                    │
│ State                   │ running                              │
│ Taints                  │ n/a                                  │
│ Labels                  │ n/a                                  │
│ Add Ons                 │ n/a                                  │
│ Image GC Min            │ 2m                                   │
│ Image Gc Low Threshold  │ 80                                   │
│ Image Gc High Threshold │ 85                                   │
┼─────────────────────────┼──────────────────────────────────────┼
➜ exo compute sks nodepool scale cluster-sc162955-001 nodepool-sc162955-001 0
error: minimum Nodepool size is 1
➜ exo version
exo 1.90.1 fedbc19d (egoscale v3.1.30)

# trying with the local build
➜ go run . compute sks nodepool scale cluster-sc162955-001 nodepool-sc162955-001 0  <-- this is the test covering the patch
[+] Are you sure you want to scale Nodepool "nodepool-sc162955-001" to 0? [yN]: y
 ✔ Scaling Nodepool "nodepool-sc162955-001"... 15s
┼─────────────────────────┼──────────────────────────────────────┼
│      SKS NODEPOOL       │                                      │
┼─────────────────────────┼──────────────────────────────────────┼
│ ID                      │ ee79ffe1-29b8-4459-ba83-46260acdc90a │
│ Name                    │ nodepool-sc162955-001                │
│ Description             │                                      │
│ Creation Date           │ 2026-01-26 15:41:25 +0000 UTC        │
│ Instance Pool ID        │ 723bcbc6-f3ef-47a8-9c3f-5cd7ac6c56a6 │
│ Instance Prefix         │ pool                                 │
│ Instance Type           │ standard.medium                      │
│ Template                │ sks-node-1.35.0-standard             │
│ Disk Size               │ 50                                   │
│ IPv6                    │ false                                │
│ Anti Affinity Groups    │ n/a                                  │
│ Security Groups         │ n/a                                  │
│ Private Networks        │ n/a                                  │
│ Version                 │ 1.35.0                               │
│ Size                    │ 0                                    │
│ State                   │ running                              │
│ Taints                  │ n/a                                  │
│ Labels                  │ n/a                                  │
│ Add Ons                 │ n/a                                  │
│ Image GC Min            │ 2m                                   │
│ Image Gc Low Threshold  │ 80                                   │
│ Image Gc High Threshold │ 85                                   │
┼─────────────────────────┼──────────────────────────────────────┼

# verifying cluster and nodepool are running
➜ exo compute sks nodepool show cluster-sc162955-001 nodepool-sc162955-001
┼─────────────────────────┼──────────────────────────────────────┼
│      SKS NODEPOOL       │                                      │
┼─────────────────────────┼──────────────────────────────────────┼
│ ID                      │ ee79ffe1-29b8-4459-ba83-46260acdc90a │
│ Name                    │ nodepool-sc162955-001                │
│ Description             │                                      │
│ Creation Date           │ 2026-01-26 15:41:25 +0000 UTC        │
│ Instance Pool ID        │ 723bcbc6-f3ef-47a8-9c3f-5cd7ac6c56a6 │
│ Instance Prefix         │ pool                                 │
│ Instance Type           │ standard.medium                      │
│ Template                │ sks-node-1.35.0-standard             │
│ Disk Size               │ 50                                   │
│ IPv6                    │ false                                │
│ Anti Affinity Groups    │ n/a                                  │
│ Security Groups         │ n/a                                  │
│ Private Networks        │ n/a                                  │
│ Version                 │ 1.35.0                               │
│ Size                    │ 0                                    │
│ State                   │ running                              │
│ Taints                  │ n/a                                  │
│ Labels                  │ n/a                                  │
│ Add Ons                 │ n/a                                  │
│ Image GC Min            │ 2m                                   │
│ Image Gc Low Threshold  │ 80                                   │
│ Image Gc High Threshold │ 85                                   │
┼─────────────────────────┼──────────────────────────────────────┼
➜ exo compute sks show cluster-sc162955-001
┼───────────────────┼──────────────────────────────────────────────────────────────┼
│    SKS CLUSTER    │                                                              │
┼───────────────────┼──────────────────────────────────────────────────────────────┼
│ ID                │ bd6def1f-8cf1-4ad1-9d6e-a472ff7c1c3f                         │
│ Name              │ cluster-sc162955-001                                         │
│ Description       │                                                              │
│ Zone              │ ch-gva-2                                                     │
│ Creation Date     │ 2026-01-26 15:33:09 +0000 UTC                                │
│ Auto-upgrade      │ false                                                        │
│ Enable kube-proxy │ true                                                         │
│ Endpoint          │ bd6def1f-8cf1-4ad1-9d6e-a472ff7c1c3f.sks-ch-gva-2.exo.io     │
│ Version           │ 1.35.0                                                       │
│ Service Level     │ starter                                                      │
│ CNI               │ calico                                                       │
│ Add-Ons           │ exoscale-cloud-controller                                    │
│                   │ metrics-server                                               │
│ Audit Enabled     │ false                                                        │
│ Feature Gates     │                                                              │
│ State             │ running                                                      │
│ Labels            │ n/a                                                          │
│ Nodepools         │ ee79ffe1-29b8-4459-ba83-46260acdc90a | nodepool-sc162955-001 │
┼───────────────────┼──────────────────────────────────────────────────────────────┼

# verifying we can scale the Nodepool up
➜ exo compute sks nodepool scale cluster-sc162955-001 nodepool-sc162955-001 2
[+] Are you sure you want to scale Nodepool "nodepool-sc162955-001" to 2? [yN]: y
 ✔ Scaling Nodepool "nodepool-sc162955-001"... 33s
┼─────────────────────────┼──────────────────────────────────────┼
│      SKS NODEPOOL       │                                      │
┼─────────────────────────┼──────────────────────────────────────┼
│ ID                      │ ee79ffe1-29b8-4459-ba83-46260acdc90a │
│ Name                    │ nodepool-sc162955-001                │
│ Description             │                                      │
│ Creation Date           │ 2026-01-26 15:41:25 +0000 UTC        │
│ Instance Pool ID        │ 723bcbc6-f3ef-47a8-9c3f-5cd7ac6c56a6 │
│ Instance Prefix         │ pool                                 │
│ Instance Type           │ standard.medium                      │
│ Template                │ sks-node-1.35.0-standard             │
│ Disk Size               │ 50                                   │
│ IPv6                    │ false                                │
│ Anti Affinity Groups    │ n/a                                  │
│ Security Groups         │ n/a                                  │
│ Private Networks        │ n/a                                  │
│ Version                 │ 1.35.0                               │
│ Size                    │ 2                                    │
│ State                   │ running                              │
│ Taints                  │ n/a                                  │
│ Labels                  │ n/a                                  │
│ Add Ons                 │ n/a                                  │
│ Image GC Min            │ 2m                                   │
│ Image Gc Low Threshold  │ 80                                   │
│ Image Gc High Threshold │ 85                                   │
┼─────────────────────────┼──────────────────────────────────────┼

[zyegfryed]

Thanks 🍰