Description of problem:

The lightspeed configuration described in the `lightspeed-stack` ConfigMap requires to use final values and you can use env variables inside `mcp_servers` section. If you use the next definition for your MCP server:

    mcp_servers:
      - name: mcp::backstage
        provider_id: model-context-protocol
        url: https://backstage-developer-hub-rhdh-gitlab.${BASEDOMAIN}/api/mcp-actions/v1 

It will fail with errors in the `llama-stack` container similar to the ones attached in this case (file: backstage-developer-hub-5546f44f8-8s6qd-llama-stack.log) backstage-developer-hub-5546f44f8-8s6qd-llama-stack.log

The env variable is defined in a secret added into `lightspeed-core` container using the `envFrom` section, such as:

              - name: lightspeed-core # Lightspeed Core Service
                image: 'quay.io/lightspeed-core/lightspeed-stack:dev-20251021-ee9f08f'
                envFrom:
                  - secretRef:
                      name: rhdh-secrets
                volumeMounts:
                  - mountPath: /app-root/lightspeed-stack.yaml
                    name: lightspeed-stack
                    subPath: lightspeed-stack.yaml
                  - mountPath: /tmp/data/feedback
                    name: shared-storage
                  - mountPath: /tmp/data/transcripts
                    name: shared-storage
                  - mountPath: /tmp/data/conversations
                    name: shared-storage 

The variable is available inside the container as we can check from the terminal:

on 🎩 ❯ oc exec $(oc get pod -l rhdh.redhat.com/app=backstage-developer-hub -n rhdh-gitlab -o jsonpath='{.items[0].metadata.name}') -c lightspeed-core -n rhdh-gitlab -- printenv BASEDOMAIN
apps.cluster-mxvsb.mxvsb.sandbox3509.opentlc.com 

However, any chat conversation fails in Lightspeed Developer UI. If the `url`variable is defined without env var and using the final value, the chat conversations work succesfully.

Prerequisites (if any, like setup, operators/versions):

Steps to Reproduce

The following GitHub repository has an example to replicate this error.

https://github.com/rmarting/rhdh-exercises/blob/main/README-ai-ls.md

Here it is the `url` definition using the env var:

https://github.com/rmarting/rhdh-exercises/blob/main/custom-app-config-gitlab/ls-stack-configmap-15.yaml#L33

Here it is injected the secret with the env variables:

https://github.com/rmarting/rhdh-exercises/blob/main/custom-app-config-gitlab/rhdh-instance-15.yaml#L55

Actual results:

Any chat conversation fails with errors in the `llama-stack` container.

Expected results:

Successful chat conversations and get responses from the LLM and MCP servers.

Reproducibility (Always/Intermittent/Only Once):

Always

Build Details:

Additional info (Such as Logs, Screenshots, etc):