From 9ce8b07839c373e484ec5864537d3c64e7e4745a Mon Sep 17 00:00:00 2001
From: Leo Palmer Sunmo <leo.sunmo@gmail.com>
Date: Fri, 3 Jul 2020 11:42:43 +1200
Subject: [PATCH] Add metadata endpoint and Kiam documentation

This adds documentation on which EC2 metadata endpoints the termination
handler relies on.
It also provides a config option to enable the termination handler to
function properly on a cluster that has Kiam deployed to manage AWS IAM
credentials.
---
 README.md | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/README.md b/README.md
index 6f92e7c1..0bc9886f 100644
--- a/README.md
+++ b/README.md
@@ -118,6 +118,32 @@ helm upgrade --install aws-node-termination-handler \
 
 For a full list of configuration options see our [Helm readme](https://github.com/aws/eks-charts/tree/master/stable/aws-node-termination-handler).
 
+## Use with Kiam
+To use the termination handler alongside [Kiam](https://github.com/uswitch/kiam) requires some extra configuration on Kiam's end.
+By default Kiam will block all access to the metadata address, so you need to make sure it passes through the requests the termination handler relies on.
+
+To add a whitelist configuration, use the following fields in the Kiam Helm chart values:
+```
+agent.whiteListRouteRegexp: '^\/latest\/meta-data\/(spot\/instance-action|events\/maintenance\/scheduled|instance-(id|type)|public-(hostname|ipv4)|local-(hostname|ipv4))$'
+```
+Or just pass it as an argument to the kiam agents:
+```
+kiam agent --whitelist-route-regexp='^\/latest\/meta-data\/(spot\/instance-action|events\/maintenance\/scheduled|instance-(id|type)|public-(hostname|ipv4)|local-(hostname|ipv4))$'
+```
+
+## Metadata endpoints
+The termination handler relies on the following metadata endpoints to function properly:
+```
+/latest/meta-data/spot/instance-action
+/latest/meta-data/events/maintenance/scheduled
+/latest/meta-data/instance-id
+/latest/meta-data/instance-type
+/latest/meta-data/public-hostname
+/latest/meta-data/public-ipv4
+/latest/meta-data/local-hostname
+/latest/meta-data/local-ipv4
+```
+
 ## Building
 For build instructions please consult [BUILD.md](./BUILD.md).