From ee882fa462d2f2ec97b3b009908df8e94a798f1d Mon Sep 17 00:00:00 2001
From: Cristian Calin <6627509+cristicalin@users.noreply.github.com>
Date: Tue, 30 Nov 2021 10:52:56 +0200
Subject: [PATCH] Add capability to use swap, requires Kube 1.22 (#8241)

* Alpha-NodeSwap: allow nodes to use swap

* CI: Add Fedora 35 with experimental swap job
---
 .gitlab-ci/packet.yml                             |  5 +++++
 docs/ci.md                                        |  2 +-
 .../node/templates/kubelet-config.v1beta1.yaml.j2 |  4 ++++
 .../kubernetes/preinstall/tasks/0010-swapoff.yml  | 10 ++++++++--
 .../files/packet_fedora35-calico-swap-selinux.yml | 15 +++++++++++++++
 5 files changed, 33 insertions(+), 3 deletions(-)
 create mode 100644 tests/files/packet_fedora35-calico-swap-selinux.yml

diff --git a/.gitlab-ci/packet.yml b/.gitlab-ci/packet.yml
index 9dc7b5713..c502a805c 100644
--- a/.gitlab-ci/packet.yml
+++ b/.gitlab-ci/packet.yml
@@ -229,6 +229,11 @@ packet_fedora34-calico-selinux:
   extends: .packet_periodic
   when: on_success
 
+packet_fedora35-calico-swap-selinux:
+  stage: deploy-part2
+  extends: .packet_pr
+  when: manual
+
 packet_amazon-linux-2-aio:
   stage: deploy-part2
   extends: .packet_pr
diff --git a/docs/ci.md b/docs/ci.md
index 46309339f..39b05f990 100644
--- a/docs/ci.md
+++ b/docs/ci.md
@@ -14,7 +14,7 @@ debian11 |  :white_check_mark: | :x: | :x: | :x: | :x: | :x: | :x: | :x: | :x: |
 debian9 |  :x: | :x: | :x: | :x: | :x: | :x: | :white_check_mark: | :x: | :x: |
 fedora33 |  :white_check_mark: | :x: | :x: | :x: | :x: | :x: | :x: | :x: | :x: |
 fedora34 |  :white_check_mark: | :x: | :x: | :x: | :white_check_mark: | :x: | :x: | :x: | :x: |
-fedora35 |  :x: | :x: | :x: | :x: | :x: | :white_check_mark: | :x: | :x: | :x: |
+fedora35 |  :white_check_mark: | :x: | :x: | :x: | :x: | :white_check_mark: | :x: | :x: | :x: |
 opensuse |  :x: | :white_check_mark: | :x: | :x: | :x: | :x: | :x: | :x: | :x: |
 oracle7 |  :x: | :white_check_mark: | :x: | :x: | :x: | :x: | :x: | :x: | :x: |
 ubuntu16 |  :x: | :white_check_mark: | :x: | :white_check_mark: | :x: | :white_check_mark: | :x: | :x: | :x: |
diff --git a/roles/kubernetes/node/templates/kubelet-config.v1beta1.yaml.j2 b/roles/kubernetes/node/templates/kubelet-config.v1beta1.yaml.j2
index 13ed5f4c4..83e5a7176 100644
--- a/roles/kubernetes/node/templates/kubelet-config.v1beta1.yaml.j2
+++ b/roles/kubernetes/node/templates/kubelet-config.v1beta1.yaml.j2
@@ -106,3 +106,7 @@ eventRecordQPS: {{ kubelet_event_record_qps }}
 shutdownGracePeriod: {{ kubelet_shutdown_grace_period }}
 shutdownGracePeriodCriticalPods: {{ kubelet_shutdown_grace_period_critical_pods }}
 {% endif %}
+{% if not kubelet_fail_swap_on|default(true) %}
+memorySwap:
+  swapBehavior: {{ kubelet_swap_behavior|default("LimitedSwap") }}
+{% endif %}
diff --git a/roles/kubernetes/preinstall/tasks/0010-swapoff.yml b/roles/kubernetes/preinstall/tasks/0010-swapoff.yml
index 3efc99b8c..4ea91d83e 100644
--- a/roles/kubernetes/preinstall/tasks/0010-swapoff.yml
+++ b/roles/kubernetes/preinstall/tasks/0010-swapoff.yml
@@ -13,11 +13,17 @@
   command: /sbin/swapon -s
   register: swapon
   changed_when: no
+
 - name: Disable swap
   command: /sbin/swapoff -a
-  when: swapon.stdout
+  when:
+    - swapon.stdout
+    - kubelet_fail_swap_on | default(True)
   ignore_errors: "{{ ansible_check_mode }}"  # noqa ignore-errors
 
 - name: Disable swapOnZram for Fedora
   command: touch /etc/systemd/zram-generator.conf
-  when: swapon.stdout and ansible_distribution in ['Fedora']
+  when:
+    - swapon.stdout
+    - ansible_distribution in ['Fedora']
+    - kubelet_fail_swap_on | default(True)
diff --git a/tests/files/packet_fedora35-calico-swap-selinux.yml b/tests/files/packet_fedora35-calico-swap-selinux.yml
new file mode 100644
index 000000000..ba6d58a59
--- /dev/null
+++ b/tests/files/packet_fedora35-calico-swap-selinux.yml
@@ -0,0 +1,15 @@
+---
+# Instance settings
+cloud_image: fedora-35
+mode: default
+
+# Kubespray settings
+auto_renew_certificates: true
+
+# Test with SELinux in enforcing mode
+preinstall_selinux_state: enforcing
+
+# Test Alpha swap feature by leveraging zswap default config in Fedora 35
+kubelet_fail_swap_on: False
+kube_feature_gates:
+  - "NodeSwap=True"