Concourse BOSH Deployment Fails with "Instance group 'web' must specify availability zone that matches availability zones of network"

Products

• VMware Tanzu Platform Core
• Concourse for VMware Tanzu

Issue/Introduction

When deploying or updating a Concourse release via BOSH (especially during infrastructure changes such as adding, migrating, or removing Availability Zones), the bosh deploy command fails at the validation step with an error similar to:

Error: Instance group 'web' must specify availability zone that matches availability zones of network 'network-name'
Task 561644 error
Updating deployment: Expected task '561644' to succeed but state is 'error'
Exit code 1

This error occurs even when the required Availability Zone exists in both the BOSH Cloud Config and the Concourse deployment manifest.

Environment

Tanzu Platform 
Concourse 

Cause

This issue is caused by a network name mismatch between the Concourse deployment manifest and the BOSH Cloud Config.

In BOSH deployments, each instance group (web, db, worker) maps to a network name defined in the deployment manifest. BOSH then checks the active Cloud Config to find a matching network definition and verify that the target Availability Zone (AZ) is supported by that network.

If the Concourse deployment manifest references an old network name instead of the exact network name defined in the Cloud Config, BOSH fails to resolve the network-to-AZ mapping and throws a validation error.

Resolution

To resolve this issue, update the Concourse deployment manifest to explicitly reference the network name defined in your BOSH Cloud Config.

1. Verify Cloud Config Network Name

Check your active cloud config to confirm the exact network name assigned to the target subnets:

bosh  cloud-config

Look for the networks block and verify the exact name field.

2. Update the Concourse Manifest

Open your Concourse deployment manifest (or vars/ops files) and update the networks mapping under instance_groups (or defaults) to match the Cloud Config network name:

instance_groups:
  - name: web
    azs: [AZ-name]
    networks:
      - name: network-name # <--- Ensure this matches Cloud Config exactly
  - name: db
    azs: [AZ-name]
    networks:
      - name: network-name 
  - name: worker
    azs: [AZ-name]
    networks:
      - name: network-name    # or concourse-network based on your setup

 

Additional Information

If in case you are using static IP for web VM, you can define it under the cloud-config section.