Adds tutorial doc for untrusted root CA

Signed-off-by: Zhongcheng Lao <[email protected]>

Author: laozc

site/content/en/docs/Tutorials/untrusted_root_certificate.md

@@ -0,0 +1,42 @@
+---
+title: "Untrusted Root Certificate"
+linkTitle: "Untrusted Root Certificate"
+weight: 1
+date: 2019-08-15
+description: >
+  Using minikube with Untrusted Root Certificate
+---
+
+## Overview
+
+Most organizations deploy their own Root Certificate and CA service inside the corporate networks.
+Internal websites, image repositories and other resources may install SSL server certificates issued by this CA service for security and privacy concerns.
+You may install the Root Certificate into the minikube VM to access these corporate resources within the cluster.
+
+## Prerequisites
+
+- Corporate X.509 Root Certificate
+- Latest minikube binary and ISO
+
+## Tutorial
+
+* The certificate must be in PEM format. You may use `openssl` to convert from DER format.
+
+```
+openssl x509 -inform der -in my_company.cer -out my_company.pem
+```
+
+* You may need to delete existing minikube VM
+
+```shell
+minikube delete
+```
+
+* Copy the certificate before creating the minikube VM
+
+```shell
+mkdir -p $HOME/.minikube/certs
+cp my_company.pem $HOME/.minikube/certs/my_company.pem
+
+minikube start
+```