From 94596388f7ebdf4c46545f4204434a4bbaaebd6b Mon Sep 17 00:00:00 2001
From: Spencer Smith <robertspencersmith@gmail.com>
Date: Fri, 14 Apr 2017 17:33:04 -0400
Subject: [PATCH] add ability for custom flags

---
 docs/vars.md                                       | 14 ++++++++++++++
 roles/kubernetes/master/defaults/main.yml          |  7 +++++++
 .../templates/manifests/kube-apiserver.manifest.j2 |  3 +++
 .../manifests/kube-controller-manager.manifest.j2  |  3 +++
 .../templates/manifests/kube-scheduler.manifest.j2 |  3 +++
 roles/kubernetes/node/defaults/main.yml            |  3 +++
 roles/kubernetes/node/templates/kubelet.j2         |  2 +-
 7 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/docs/vars.md b/docs/vars.md
index 966b3ffc8..603a614b2 100644
--- a/docs/vars.md
+++ b/docs/vars.md
@@ -98,6 +98,20 @@ Stack](https://github.com/kubernetes-incubator/kargo/blob/master/docs/dns-stack.
   loaded by preinstall kubernetes processes.  For example, ceph and rbd backed volumes.  Set this variable to
   true to let kubelet load kernel modules.
 
+##### Custom flags for Kube Components
+For all kube components, custom flags can be passed in. This allows for edge cases where users need changes to the default deployment that may not be applicable to all deployments. This can be done by providing a list of flags. Example:
+```
+kubelet_custom_flags:
+  - "--eviction-hard=memory.available<100Mi"
+  - "--eviction-soft-grace-period=memory.available=30s"
+  - "--eviction-soft=memory.available<300Mi"
+```
+The possible vars are:
+* *apiserver_custom_flags*
+* *controller_mgr_custom_flags*
+* *scheduler_custom_flags*
+* *kubelet_custom_flags*
+
 #### User accounts
 
 Kargo sets up two Kubernetes accounts by default: ``root`` and ``kube``. Their
diff --git a/roles/kubernetes/master/defaults/main.yml b/roles/kubernetes/master/defaults/main.yml
index 016df0c64..bd5461239 100644
--- a/roles/kubernetes/master/defaults/main.yml
+++ b/roles/kubernetes/master/defaults/main.yml
@@ -51,3 +51,10 @@ kube_oidc_auth: false
 # kube_oidc_ca_file: {{ kube_cert_dir }}/ca.pem
 # kube_oidc_username_claim: sub
 # kube_oidc_groups_claim: groups
+
+##Variables for custom flags
+apiserver_custom_flags: []
+
+controller_mgr_custom_flags: []
+
+scheduler_custom_flags: []
\ No newline at end of file
diff --git a/roles/kubernetes/master/templates/manifests/kube-apiserver.manifest.j2 b/roles/kubernetes/master/templates/manifests/kube-apiserver.manifest.j2
index 967f0a9cb..721474466 100644
--- a/roles/kubernetes/master/templates/manifests/kube-apiserver.manifest.j2
+++ b/roles/kubernetes/master/templates/manifests/kube-apiserver.manifest.j2
@@ -81,6 +81,9 @@ spec:
 {% if kube_api_anonymous_auth is defined and kube_version | version_compare('v1.5', '>=')  %}
     - --anonymous-auth={{ kube_api_anonymous_auth }}
 {% endif %}
+{% for flag in apiserver_custom_flags %}
+    - {{ flag }}
+{% endfor %}
     livenessProbe:
       httpGet:
         host: 127.0.0.1
diff --git a/roles/kubernetes/master/templates/manifests/kube-controller-manager.manifest.j2 b/roles/kubernetes/master/templates/manifests/kube-controller-manager.manifest.j2
index 477d6a64f..0f66509ad 100644
--- a/roles/kubernetes/master/templates/manifests/kube-controller-manager.manifest.j2
+++ b/roles/kubernetes/master/templates/manifests/kube-controller-manager.manifest.j2
@@ -46,6 +46,9 @@ spec:
     - --configure-cloud-routes=true
     - --cluster-cidr={{ kube_pods_subnet }}
 {% endif %}
+{% for flag in controller_mgr_custom_flags %}
+    - {{ flag }}
+{% endfor %}
     livenessProbe:
       httpGet:
         host: 127.0.0.1
diff --git a/roles/kubernetes/master/templates/manifests/kube-scheduler.manifest.j2 b/roles/kubernetes/master/templates/manifests/kube-scheduler.manifest.j2
index 7431ddf3d..a549d5296 100644
--- a/roles/kubernetes/master/templates/manifests/kube-scheduler.manifest.j2
+++ b/roles/kubernetes/master/templates/manifests/kube-scheduler.manifest.j2
@@ -27,6 +27,9 @@ spec:
     - --leader-elect=true
     - --master={{ kube_apiserver_endpoint }}
     - --v={{ kube_log_level }}
+{% for flag in scheduler_custom_flags %}
+    - {{ flag }}
+{% endfor %}
     livenessProbe:
       httpGet:
         host: 127.0.0.1
diff --git a/roles/kubernetes/node/defaults/main.yml b/roles/kubernetes/node/defaults/main.yml
index 952214179..7f1e6f4a0 100644
--- a/roles/kubernetes/node/defaults/main.yml
+++ b/roles/kubernetes/node/defaults/main.yml
@@ -45,3 +45,6 @@ etcd_config_dir: /etc/ssl/etcd
 kube_apiserver_node_port_range: "30000-32767"
 
 kubelet_load_modules: false
+
+##Support custom flags to be passed to kubelet
+kubelet_custom_flags: []
\ No newline at end of file
diff --git a/roles/kubernetes/node/templates/kubelet.j2 b/roles/kubernetes/node/templates/kubelet.j2
index ba02e5eb9..d2ca95ad4 100644
--- a/roles/kubernetes/node/templates/kubelet.j2
+++ b/roles/kubernetes/node/templates/kubelet.j2
@@ -44,7 +44,7 @@ KUBELET_HOSTNAME="--hostname-override={{ ansible_hostname }}"
 {%   set node_labels %}--node-labels=node-role.kubernetes.io/node=true{% endset %}
 {% endif %}
 
-KUBELET_ARGS="{{ kubelet_args_base }} {{ kubelet_args_dns }} {{ kubelet_args_kubeconfig }} {{ node_labels }}"
+KUBELET_ARGS="{{ kubelet_args_base }} {{ kubelet_args_dns }} {{ kubelet_args_kubeconfig }} {{ node_labels }} {% for flag in kubelet_custom_flags %} {{flag}} {% endfor %}"
 {% if kube_network_plugin is defined and kube_network_plugin in ["calico", "weave", "canal"] %}
 KUBELET_NETWORK_PLUGIN="--network-plugin=cni --network-plugin-dir=/etc/cni/net.d --cni-bin-dir=/opt/cni/bin"
 {% elif kube_network_plugin is defined and kube_network_plugin == "weave" %}