App Platform is a Platform-as-a-Service (PaaS) offering that allows developers to publish code directly to DigitalOcean servers without worrying about the underlying infrastructure.
App Platform apps run in Docker containers that contain the app’s stack, which includes the OS, buildpack, and other dependencies. You can upgrade or downgrade the app’s stack by changing your app’s spec to a specified Ubuntu version, which upgrades or downgrades the container’s OS, buildpacks, and dependencies.
As of October 2023, all apps on App Platform run on Ubuntu 22. To check which version of Ubuntu your app uses, navigate to your app’s Overview page, then click the Settings tab. The app’s stack version is listed in the Build Phase section.
To change your app’s stack, go to the Apps page in the DigitalOcean Control Panel and click your app. Click the Settings tab, scroll to the App Spec section, and click the Edit button. Here, you can download the spec to edit it in your preferred text editor or edit the spec directly in the control panel.
To change the stack, add a feature field to the spec (if one doesn’t already exist) and set the value to either buildpack-stack=ubuntu-22 or buildpack-stack=ubuntu-18, like this:
...
name: example-app
region: nyc
features:
- buildpack-stack=ubuntu-18
services:
- build_command: npm run build
environment_slug: node-js
github:
branch: master
deploy_on_push: true
repo: example/app-repo
http_port: 8080
instance_count: 2
instance_size_slug: professional-xs
name: reactions
run_command: npm start
source_dir: /
If you edited the spec in the control panel, click Save to update your app. If you downloaded the spec, instead click Upload File, select your updated spec, and click Replace. Either way, this automatically triggers a deployment with the specified Ubuntu version.