From 78411d40cbf1ff98896f0f69760d03c0bbf1c16a Mon Sep 17 00:00:00 2001
From: Vincent Hou <shou@us.ibm.com>
Date: Thu, 23 Jan 2020 15:18:01 -0500
Subject: [PATCH 1/2] Add the instruction on how to upgrade v0.10 and v0.11 to
 v0.12

---
 README.md            |  4 ++++
 doc/upgrade_guide.md | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+)
 create mode 100644 doc/upgrade_guide.md

diff --git a/README.md b/README.md
index 1a84f894..ec916998 100644
--- a/README.md
+++ b/README.md
@@ -183,3 +183,7 @@ spec:
   channel: alpha
 EOF
 ```
+
+## Upgrade
+
+Please refer to the [upgrade guide](doc/upgrade_guide.md) for a safe upgrade process.
diff --git a/doc/upgrade_guide.md b/doc/upgrade_guide.md
new file mode 100644
index 00000000..eb6edf87
--- /dev/null
+++ b/doc/upgrade_guide.md
@@ -0,0 +1,32 @@
+# Upgrade Guide
+
+This document describes how to upgrade the serving-operator to an expected version.
+
+## Backup precaution
+
+As an administrator, you are recommended to save the content of the custom resource for serving-operator
+before upgrading your operator. Make sure that you know the name and the namespace of your CR, and use the
+following command to save the CR in a file called `serving_operator_cr.yaml`:
+
+For the version v0.10.0 or later:
+
+```
+kubectl get KnativeServing <cr-name> -n <namespace> -o=yaml > serving_operator_cr.yaml
+```
+
+Replace `<cr-name>` with the name of your CR, and `<namespace>` with the namespace.
+
+One version of serving-operator installs only one specific version of Knative Serving. With your
+operator successfully upgraded, your Knative Serving is upgraded as well.
+
+## v0.10.0, v0.11.x -> v0.12.0
+
+Both of v0.10 and v0.11 versions are able to upgrade to the version v0.12.0 by running the following command:
+
+```
+kubectl apply -f https://github.com/knative/serving-operator/releases/download/v0.12.0/serving-operator.yaml
+```
+
+## v0.9.0 or earlier
+
+There is no upgrade support for the version v0.9.0 or any unofficial version prior to it.

From bd56e199605eda66cb8ba334f39e24078fc3720f Mon Sep 17 00:00:00 2001
From: Vincent Hou <shou@us.ibm.com>
Date: Thu, 23 Jan 2020 16:01:42 -0500
Subject: [PATCH 2/2] Remove the section about 0.9 version

---
 doc/upgrade_guide.md | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/doc/upgrade_guide.md b/doc/upgrade_guide.md
index eb6edf87..88a8916a 100644
--- a/doc/upgrade_guide.md
+++ b/doc/upgrade_guide.md
@@ -26,7 +26,3 @@ Both of v0.10 and v0.11 versions are able to upgrade to the version v0.12.0 by r
 ```
 kubectl apply -f https://github.com/knative/serving-operator/releases/download/v0.12.0/serving-operator.yaml
 ```
-
-## v0.9.0 or earlier
-
-There is no upgrade support for the version v0.9.0 or any unofficial version prior to it.