From 3009c7715ddcb61475c1753ef00453c2ab78ca07 Mon Sep 17 00:00:00 2001
From: Jason Deal <jmdeal@amazon.com>
Date: Thu, 26 Oct 2023 10:47:59 -0700
Subject: [PATCH] update docs

---
 .../en/preview/concepts/nodeclasses.md        | 71 ++++++++++++++-----
 1 file changed, 54 insertions(+), 17 deletions(-)

diff --git a/website/content/en/preview/concepts/nodeclasses.md b/website/content/en/preview/concepts/nodeclasses.md
index 946cacb96d39..5665d5dd687f 100644
--- a/website/content/en/preview/concepts/nodeclasses.md
+++ b/website/content/en/preview/concepts/nodeclasses.md
@@ -29,35 +29,35 @@ metadata:
   name: default
 spec:
   # required, resolves a default ami and userdata
-  amiFamily: AL2                
-  
+  amiFamily: AL2
+
   # required, discovers subnets to attach to instances
-  subnetSelectorTerms:          
+  subnetSelectorTerms:
     - tags:
         karpenter.sh/discovery: "${CLUSTER_NAME}"
-  
+
   # required, discovers security groups to attach to instances
-  securityGroupSelectorTerms:   
+  securityGroupSelectorTerms:
     - tags:
         karpenter.sh/discovery: "${CLUSTER_NAME}"
 
   # optional, discovers amis to override the amiFamily's default
-  amiSelectorTerms:             
+  amiSelectorTerms:
     - tags:
         karpenter.sh/discovery: "${CLUSTER_NAME}"
-  
+
   # optional, IAM role to use for the node identity
   role: "KarpenterNodeRole-${CLUSTER_NAME}"
-  
+
   # optional, overrides autogenerated userdata with a merge semantic
-  userData: |                   
+  userData: |
     echo "Hello world"
 
   # optional, propagates tags to underlying EC2 resources
-  tags:                  
+  tags:
     team: team-a
     app: team-a-app
-  
+
   # optional, configures IMDS for the instance
   metadataOptions:
     httpEndpoint: enabled
@@ -65,6 +65,11 @@ spec:
     httpPutResponseHopLimit: 2
     httpTokens: required
 
+  # options, configure network interfaces for the instance
+    - associatePublicIPAddress: true
+      description: "a network interface"
+      deviceIndex: 0
+
   # optional, configures storage devices for the instance
   blockDeviceMappings:
     - deviceName: /dev/xvda
@@ -95,7 +100,7 @@ status:
       zone: us-east-2c
     - id: subnet-03941e7ad6afeaa72
       zone: us-east-2a
-  
+
   # resolved security groups
   securityGroups:
     - id: sg-041513b454818610b
@@ -103,7 +108,7 @@ status:
     - id: sg-0286715698b894bca
       name: ControlPlaneSecurityGroup-1AQ073TSAAPW
 
-  # resolved AMIs 
+  # resolved AMIs
   amis:
     - id: ami-01234567890123456
       name: custom-ami-amd64
@@ -119,7 +124,7 @@ status:
           operator: In
           values:
             - arm64
-  
+
   # generated instance profile name
   instanceProfile: "${CLUSTER_NAME}-0123456778901234567789"
 ```
@@ -206,7 +211,7 @@ Karpenter will automatically query for the appropriate [EKS optimized AMI](https
 
 ### Custom
 
-The `Custom` AMIFamily ships without any default userData to allow you to configure custom bootstrapping for control planes or images that don't support the default methods from the other families. 
+The `Custom` AMIFamily ships without any default userData to allow you to configure custom bootstrapping for control planes or images that don't support the default methods from the other families.
 
 ## spec.subnetSelectorTerms
 
@@ -265,7 +270,7 @@ spec:
 ## spec.securityGroupSelectorTerms
 
 The security group of an instance is comparable to a set of firewall rules.
-[EKS creates at least two security groups by default](https://docs.aws.amazon.com/eks/latest/userguide/sec-group-reqs.html). 
+[EKS creates at least two security groups by default](https://docs.aws.amazon.com/eks/latest/userguide/sec-group-reqs.html).
 
 {{% alert title="Tip" color="secondary" %}}
 Security groups may be specified by any tag, including "Name". Selecting tags using wildcards (`*`) is supported.
@@ -531,6 +536,38 @@ spec:
 
 The `Custom` AMIFamily ships without any default `blockDeviceMappings`.
 
+## spec.networkInterfaces
+
+The `networkInterfaces` field on the AWSNodeTemplate is mapped to [AWS EC2 LaunchTemplate NetworkInterfaces](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-ec2-launchtemplate-networkinterface.html)
+and can be used to configure the network interfaces that AWS EC2 will attach to the provisioned nodes.
+
+Learn more about [Network Interfaces](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-eni.html).
+
+### Examples
+
+Single network interface (with associated public IP):
+```yaml
+apiVersion: karpenter.k8s.aws/v1alpha1
+kind: AWSNodeTemplate
+spec:
+  networkInterfaces:
+    - associatePublicIPAddress: true
+      description: "a network interface"
+      deviceIndex: 1
+```
+
+Multiple network interfaces:
+```yaml
+apiVersion: karpenter.k8s.aws/v1alpha1
+kind: AWSNodeTemplate
+spec:
+  networkInterfaces:
+    - description: "main network interface"
+      deviceIndex: 0
+    - description: "secondary network interface"
+      deviceIndex: 1
+```
+
 ## spec.userData
 
 You can control the UserData that is applied to your worker nodes via this field. This allows you to run custom scripts or pass-through custom configuration to Karpenter instances on start-up.
@@ -880,4 +917,4 @@ spec:
   role: "KarpenterNodeRole-${CLUSTER_NAME}"
 status:
   instanceProfile: "${CLUSTER_NAME}-0123456778901234567789"
-```
\ No newline at end of file
+```