Container image digest references (@sha256) rejected in Portal and Terraform/Terragrunt deployments

[alirezza]

This issue is a: (mark with an x)

• bug report -> please search issues before submitting
• documentation issue or request
• regression (a behavior that used to work and stopped in a new release)

Issue description

The Azure Container Apps Portal rejects valid container image digest references in params.json with a client-side validation error. Currently, only image tags are supported, which leads to incorrect image pulls when tags are reused.

Steps to reproduce

1. Create a Container App deployment configuration
2. Reference the image as registry/repository@sha256:<digest> instead of just registry/repository:tag
3. Attempt to deploy through the Portal
4. Observe the validation error from the Portal

Expected behavior
The Portal should accept both notations:

• registry/repository:tag (currently works)
• registry/repository@sha256:<digest> (should work)

Actual behavior
Client-side validation rejects digest-based references. The error message indicates that only tag notation is supported, causing image pull failures.

Error Message

Container was terminated with exit code 27 and reason 'ImagePullFailure'. 
Pull image: registry/repository@sha256:... failed with exit code 1