Custom CPU/RAM resource constraints

[SufyExpert]

How do we apply custom CPU/RAM resource constraints to containers deployed via the CasaOS App Store?

When installing applications from the native CasaOS App Store or community repositories, the underlying Docker Compose files generally deploy containers without any resource restrictions. On low-resource environments or shared homelab servers, a single container (like a media transcoder or database sync tool) can easily spike and cause kernel panic or OOM (Out Of Memory) kills on critical CasaOS services.

Since the GUI configuration panel doesn't expose sliders for resource limitations, what is the best practice for injecting deploy.resources limits into a CasaOS-managed application so that the constraints survive web-app updates?

[Muhammad-Ahmed-Zia]

CasaOS stores its active application configurations as standard Docker Compose structures. You can append native Docker Compose V3 resource limits by modifying the local App management files directly.

1. Locate the App's Compose File

Every application installed via CasaOS has its configuration stored in /var/lib/casaos/apps/. Navigate to the directory of the target application:

cd /var/lib/casaos/apps/[app_name]/

Open the docker-compose.yml file using your preferred editor.

2. Inject the Resource Constraints

Under the specific container service definition, add the deploy block specifying your maximum limits (e.g., capping the app at 2 CPU cores and 1GB of RAM):

services:
  app-service-name:
    image: example:latest
    # ... existing configuration ...
    deploy:
      resources:
        limits:
          cpus: '2.0'
          memory: 1024M

3. Re-import and Recreate the Container

Do not just restart the container via Docker commands. Let CasaOS update its internal state machine by reloading the app directly from the terminal or using the "Update" action in the Web UI dashboard to reconstruct the container with the new configuration:

casaos-app-management-cli app apply [app_name] /var/lib/casaos/apps/[app_name]/docker-compose.yml

This forces the Docker engine to apply the hard execution boundaries, protecting the rest of your CasaOS environment from resource exhaustion.