Merge pull request #112356 from v-miegge/v-miegge/python-3-enabled-linux

CI 117060 - Created file, updated TOC

Author: ShannonLeavitt

articles/virtual-machines/extensions/issues-using-vm-extensions-python-3.md

@@ -0,0 +1,89 @@
+---
+title: Issues using VM extensions in Python 3-enabled Linux Azure Virtual Machines systems 
+description: Learn about using VM extensions in Python 3-enabled Linux systems
+services: virtual-machines-windows
+documentationcenter: ''
+author: v-miegge
+ms.author: jparrel
+manager: dcscontentpm
+editor: ''
+tags: top-support-issue,azure-resource-manager
+
+ms.service: virtual-machines-windows
+ms.topic: article
+ms.tgt_pltfrm: vm-windows
+ms.workload: infrastructure-services
+ms.date: 04/22/2020
+ms.assetid: 3cd520fd-eaf7-4ef9-b4d3-4827057e5028
+---
+
+# Issues using VM extensions in Python 3-enabled Linux Azure Virtual Machines systems
+
+> [!NOTE]
+> Microsoft encourages users to adopt **Python 3.x** in their systems unless your workload requires **Python 2.x** support. Examples of this requirement might include legacy administration scripts, or extensions such as **Azure Disk Encryption** and **Azure Monitor**.
+>
+> Before installing **Python 2.x** in production, consider the question of long-term support of Python 2.x, particularly their ability to receive security updates. As products, including some of the extension mentioned, update with **Python 3.8** support, you should discontinue use of Python 2.x.
+
+Some Linux distributions have transitioned to Python 3.8 and removed the legacy `/usr/bin/python` entrypoint for Python altogether. This transition impacts the out-of-the-box, automated deployment of certain virtual machine (VM) extensions with the following conditions:
+
+- Extensions that are still transitioning to Python 3.x support
+- Extensions that use the legacy `/usr/bin/python` entrypoint
+
+Linux distribution users who have transitioned to **Python 3.x** must ensure the legacy `/usr/bin/python` entrypoint exists before attempting to deploy those extensions to their VMs. Otherwise, the extension deployment might fail. 
+
+- Endorsed Linux distributions that are affected include **Ubuntu Server 20.04 LTS** and **Ubuntu Pro 20.04 LTS**.
+
+- Affected VM Extensions include **Azure Disk Encryption**, **Log Analytics**, **VM Access** (used for Password Reset), and **Guest Diagnostics** (used for additional performance counters).
+
+In-place upgrades, such as upgrading from **Ubuntu 18.04 LTS** to **Ubuntu 20.04 LTS**, should retain the `/usr/bin/python` symlink, and remain unaffected.
+
+## Resolution
+
+Consider the following general recommendations before deploying extensions in the known-affected scenarios described previously in the Summary:
+
+1.	Before deploying the extension, reinstate the `/usr/bin/python` symlink by using the Linux distribution vendor-provided method.
+
+    - For example, for **Python 2.7**, use: `sudo apt update && sudo apt install python-is-python2`
+
+2.	If you’ve already deployed an instance that exhibits this problem, use the **Run command** functionality in the **VM blade** to run the commands mentioned above. The Run command extension itself is not affected by the transition to Python 3.8.
+
+3.	If you are deploying a new instance, and need to set an extension at provisioning time, use **cloud-init** user data to install the packages mentioned above.
+
+    For example, for Python 2.7:
+
+    ```
+    # create cloud-init config
+    cat > cloudinitConfig.json <<EOF
+    #cloud-config
+    package_update: true
+    
+    runcmd:
+    - sudo apt update
+    - sudo apt install python-is-python2 
+    EOF
+    
+    # create VM
+    az vm create \
+        --resource-group <resourceGroupName> \
+        --name <vmName> \
+        --image <Ubuntu 20.04 Image URN> \
+        --admin-username azadmin \
+        --ssh-key-value "<sshPubKey>" \
+        --custom-data ./cloudinitConfig.json
+    ```
+
+4.	If your organization’s policy administrators determine that extensions shouldn’t be deployed in VMs, you can disable extension support at provisioning time:
+
+    - REST API
+
+      To disable and enable extensions when you can deploy a VM with this property:
+
+      ```
+        "osProfile": {
+          "allowExtensionOperations": false
+        },
+      ```
+
+## Next steps
+
+Please refer to [Other base system changes since 18.04 LTS - Python 3 by default](https://wiki.ubuntu.com/FocalFossa/ReleaseNotes#Python3_by_default) for additional information.

articles/virtual-machines/extensions/toc.yml

@@ -125,3 +125,5 @@
     href: export-templates.md
   - name: Troubleshoot
     href: troubleshoot.md
+  - name: Issues with Python 3-enabled Linux systems
+    href: issues-using-vm-extensions-python-3.md