security updates after the end of support and maintenance for Ubuntu 16.04 LTS - Elastic Compute Service

In April 2021, Ubuntu 16.04 LTS (Xenial Xerus) reached the end of the standard 5-year security maintenance window. Therefore, Alibaba Cloud no longer provides updates for Ubuntu 16.04 LTS public images. Ubuntu 16.04 LTS transitions into the Expanded Security Maintenance (ESM) support phase. You can perform the operations described in this topic and use the Ubuntu Advantage for Infrastructure (UA-I) subscription to obtain updates under the ESM program for Ubuntu 16.04.

Background information

While Ubuntu 16.04 LTS is in the ESM support phase, you can use ESM in the UA-I subscription to continue receiving security updates for the Ubuntu base operating systems, critical software packages, and infrastructure components. For more information, see Ubuntu Advantage for Infrastructure and Expanded Security Maintenance (ESM).

If you want to continue receiving security updates for the operating system of an Ubuntu 16.04 instance, perform the following steps.

Step 1: Subscribe to the UA-I service on the official Ubuntu website

On your computer, open a browser and go to the official Ubuntu website.
In the top navigation bar, click Sign in.
Use an Ubuntu account to log on to the official Ubuntu website. If you do not have an Ubuntu account, create an account as prompted and then log on to the website.
Go to the SUBSCRIPTION page and then click Register.
In the Free Personal Token section, obtain and save the token value.

Step 2: Add UA-I to the Ubuntu 16.04 instance and perform security updates

Connect to the Ubuntu 16.04 instance.
For more information, see Connect to a Linux instance by using a password or key.
Run the following commands in sequence to install the latest Ubuntu Advantage (UA) client:
1. Update the software packages in the software repository.
```
sudo apt update
```
2. Install the UA client.
```
sudo apt install ubuntu-advantage-tools
```
Run the token value that you saved in Step 1.
Run the command in the following format. Replace the <token> parameter with the value that you saved.
```
sudo ua attach <token>
```
The following sample command output indicates that ESM is enabled.
(Optional) Run the following command to enable ESM.
If you are unsure whether ESM is enabled, run the following command to ensure that ESM is enabled:
```
sudo ua enable esm-infra
```
Run the following commands in sequence to update and upgrade the software packages:
1. Update the software packages in the software repository.
```
sudo apt update
```
2. Upgrade the software packages.
```
sudo apt upgrade 
```