docker-compose-8.8: Identity container fails to connect to Keycloak on startup

[gorazd-dimovski]

Issue Description

Environment

• Docker Compose version: 8.8 (downloaded from https://docs.camunda.io/docs/self-managed/quickstart/developer-quickstart/docker-compose/)
• Platform: macOS with Colima
• Download date: November 12, 2025

Problem
When running docker-compose -f docker-compose-full.yaml up -d with the default configuration, the identity container fails to start due to connection errors with Keycloak.

Error from identity container logs:
ERROR: Unable to connect to Keycloak.
ERROR: RESTEASY004655: Unable to invoke request: org.apache.http.NoHttpResponseException: host.docker.internal:18080 failed to respond

Version Details

• Not working (current docker-compose-8.8 release from Nov 12, 2025):

  • Camunda: 8.8.3
  • Console: 8.8.35
  • Connectors: 8.8.2
  • Optimize: 8.8.1

• Working (previous docker-compose-8.8 release):

  • Camunda: 8.8.2
  • Console: 8.8.17
  • Connectors: 8.8.1
  • Optimize: 8.8.0

Observation
The default .env file contains:
KEYCLOAK_HOST=host.docker.internal

The identity container attempts to connect to Keycloak using host.docker.internal:18080, which fails. The Keycloak container itself is healthy and running, but identity cannot establish a connection.

Expected Behavior
The default configuration should work out-of-the-box without requiring manual configuration changes.