Merge pull request 2i2c-org#4458 from GeorgianaElena/document-dedicat…

…ed-nodepools

[docs] How to do dedicated nodes on aws

docs/howto/features/dedicated-nodepool.md

@@ -8,7 +8,9 @@ Some hubs on shared clusters require dedicated nodepools, for a few reasons:
 2. (In the future) Helpful with cost isolation, as we can track how much a
    nodepool is costing us.
 
-## GCP
+`````{tab-set}
+````{tab-item} GCP
+:sync: gcp-key
 
 1. Setup a new nodepool in terraform, via the `<cluster-name>.tfvars` for the
    cluster. Add the new nodepool to `notebook_nodes`:
@@ -71,7 +73,79 @@ Some hubs on shared clusters require dedicated nodepools, for a few reasons:
 
    This tells JupyterHub to place user pods from this hub on the nodepool we had
    just created!
-
+````
+
+````{tab-item} AWS
+:sync: aws-key
+
+1. Setup a new nodepool in eksctl, via the `eksctl/<cluster-name>.jsonnet` for the
+   cluster. Add the new nodepool to `notebookNodes`:
+
+   ```
+   notebookNodes = [
+   {
+      {
+        instanceType: "<type>",
+        nameSuffix: 'dedicated',
+        labels+: {
+            "2i2c.org/community": "<community-name>"
+        },
+        tags+: {
+            "community": "<community-name>"
+        },
+        taints+: {
+            "2i2c.org/community": "<community-name>:NoSchedule"
+        },
+      },
+   }]
+   ```
+
+   This sets up a new node with:
+
+   1. Kubernetes labels so we can tell the scheduler that user pods of this hub
+      should come to this nodepool.
+   2. Kubernetes taints so user pods of *other* hubs will not be scheduled on this
+      nodepool.
+   3. AWS tags (unrelated to Kubernetes Labels!) that help us track costs.
+      The key name here is different from (1) and (2) because it must start with a
+      letter, and can not contain `/`.
+
+   Once done, run:
+
+   1. Export the jsonnet to eksctl.yaml
+
+      ```bash
+      jsonnet $CLUSTER_NAME.jsonnet > $CLUSTER_NAME.eksctl.yaml
+      ```
+   2. Create the new nodepool
+
+      ```bash
+      eksctl create nodegroup -f $CLUSTER_NAME.eksctl.yaml
+      ```
+
+2. Configure the hub's helm values to use this nodepool, and this nodepool only.
+
+   ```yaml
+   jupyterhub:
+     singleuser:
+       nodeSelector:
+         2i2c.org/community: <community-name>
+       extraTolerations:
+         - key: 2i2c.org/community
+           operator: Equal
+           value: <community-name>
+           effect: NoSchedule
+   ```
+
+   ```{note}
+   If this is a `daskhub`, nest these under a `basehub` key.
+   ```
+
+   This tells JupyterHub to place user pods from this hub on the nodepool we had
+   just created!
+````
+`````
+
 ## Node type and minimum nodepool size considerations
 
 When setting up a dedicated node pool for a hub, particularly a hub supporting