执行Camunda 8 Platform Spring示例时zeebeClientLifecycle Bean启动失败，请求排查指导

Hey there, let's work through this issue you're hitting with your Camunda 8 Spring Boot example. The key clue in your error stack is the bottom-most exception: java.io.IOException: Failed while requesting access token with status code 404 and message Not Found — this tells us your application is still trying to use OAuth authentication (for Camunda Cloud) even though you're connecting to a local cluster, which doesn't require OAuth.

Here's how to fix this step-by-step:

1. Fix Your application.properties Configuration #

Make sure your local configuration explicitly disables OAuth and points to your local Zeebe gateway. Update your application.properties with these settings:

# Clear all Camunda Cloud OAuth-related properties (not needed for local clusters)
zeebe.client.cloud.region=
zeebe.client.cloud.cluster-id=
zeebe.client.cloud.client-id=
zeebe.client.cloud.client-secret=

# Point to your local Zeebe gateway (default port for docker-compose is 26500)
zeebe.client.broker.gateway-address=localhost:26500

# Enable plaintext communication (local clusters don't use TLS by default)
zeebe.client.security.plaintext=true

This ensures your client skips OAuth attempts and connects directly to your Docker-hosted Zeebe cluster.

2. Verify Docker Port Mapping #

Double-check that your Zeebe gateway container has port 26500 mapped to your host machine. Run docker ps and look for the Zeebe gateway entry — it should show a port binding like:

0.0.0.0:26500->26500/tcp

If the port isn't mapped, review your docker-compose.yml to ensure the Zeebe gateway service has the correct port binding configuration.

3. Clean and Rebuild Your Project #

Spring Boot sometimes caches old configurations, so do a full clean to eliminate any stale settings:

• For Maven: Run mvn clean install
• For Gradle: Run ./gradlew clean build
  Then restart your application with the fresh build.

4. Validate Local Zeebe Cluster Health #

Use the Zeebe command-line tool (zbctl) to confirm your local cluster is reachable:

zbctl status --insecure

If this returns valid cluster details (like broker info and leader status), your local Zeebe is running correctly and accessible from your host.

Bonus: Confirm Configuration Loading #

Check your application's startup logs for lines like Loaded configuration from 'classpath:/application.properties' to ensure your local configuration file is being picked up instead of any leftover cloud settings.

If you follow these steps, your Spring Boot application should connect to your local Camunda 8 cluster without the OAuth-related error.

内容的提问来源于stack exchange，提问作者Andy Dufresne