settings: adds new node-labels, node-taints settings

Adds `node-labels` and `node-taints` settings for kubelet.
Allows users to label and taint the node through userdata

Updates README with descriptions of the new settings

README.md

@@ -237,6 +237,19 @@ See the [setup guide](INSTALL.md) for *much* more detail on setting up Thar and
 * `settings.kubernetes.cluster-certificate`: This is the base64-encoded certificate authority of the cluster.
 * `settings.kubernetes.api-server`: This is the cluster's Kubernetes API endpoint.
 
+The following settings can be optionally set to customize the node labels and taints. 
+* `settings.kubernetes.node-labels`: [Labels](https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/) in the form of key, value pairs added when registering the node in the cluster.
+* `settings.kubernetes.node-taints`: [Taints](https://kubernetes.io/docs/concepts/configuration/taint-and-toleration/) in the form of key, value and effect entries added when registering the node in the cluster.
+  * Example user data for setting up labels and taints:
+    ```
+    [settings.kubernetes.node-labels]
+    label1 = "foo"
+    label2 = "bar"
+    [settings.kubernetes.node-taints]
+    dedicated = "experimental:PreferNoSchedule"
+    special = "true:NoSchedule"
+    ```
+
 The following settings are set for you automatically by [pluto](workspaces/api/) based on runtime instance information, but you can override them if you know what you're doing!
 * `settings.kubernetes.max-pods`: The maximum number of pods that can be scheduled on this node (limited by number of available IPv4 addresses)
 * `settings.kubernetes.cluster-dns-ip`: The CIDR block of the primary network interface.

packages/kubernetes/kubelet-env

@@ -1,2 +1,4 @@
 NODE_IP={{settings.kubernetes.node-ip}}
+NODE_LABELS={{join_map "=" "," "no-fail-if-missing" settings.kubernetes.node-labels}}
+NODE_TAINTS={{join_map "=" "," "no-fail-if-missing" settings.kubernetes.node-taints}}
 POD_INFRA_CONTAINER_IMAGE={{settings.kubernetes.pod-infra-container-image}}

packages/kubernetes/kubelet.service

@@ -19,6 +19,8 @@ ExecStart=/usr/bin/kubelet \
     --cert-dir /var/lib/kubelet/pki \
     --volume-plugin-dir /var/lib/kubelet/plugins/volume/exec \
     --node-ip ${NODE_IP} \
+    --node-labels "${NODE_LABELS}" \
+    --register-with-taints "${NODE_TAINTS}" \
     --pod-infra-container-image ${POD_INFRA_CONTAINER_IMAGE}
 
 Restart=on-failure

workspaces/api/apiserver/src/model.rs

@@ -55,6 +55,12 @@ pub struct KubernetesSettings {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub api_server: Option<String>,
 
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub node_labels: Option<HashMap<SingleLineString, SingleLineString>>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub node_taints: Option<HashMap<SingleLineString, SingleLineString>>,
+
     // Dynamic settings.
 
     #[serde(skip_serializing_if = "Option::is_none")]