How to Judge Whether BOSH Runtime Config Has Been Applied to a Deployment

Products

• VMware Tanzu Platform - Kubernetes

Issue/Introduction

In BOSH-managed environments, runtime configs are powerful tools for injecting global behaviors—like logging agents, security hardening, or monitoring sidecars—across deployments. However, runtime configs are not automatically applied to existing deployments until a bosh deploy or apply-changes is triggered. This creates a subtle operational gap: how do you know whether a runtime config has actually been applied to a given deployment?

This article introduces a timestamp-based audit strategy to detect whether a deployment is potentially out-of-sync with the latest runtime config.

Resolution

• Strategy Overview

We’ll compare two key timestamps:

Metric	Description
Runtime Config Last Updated	When the runtime config was last changed in the BOSH Director
Deployment Addon Application Time	When the deployment last applied runtime config via apply-addons

 

If the addon application time is older than the runtime config update, the deployment is likely missing the latest runtime config and will reapply it on the next deploy.

• Step-by-Step Implementation

1.) Retrieve Runtime Config Update Time.

Use the BOSH CLI to list the latest change time of runtime config in bosh director.

ubuntu@####:~$ bosh configs
Using environment '1##.1##.1##.1##' as client 'ops_manager'
ID   Type     Name                              Team                            Created At 
14*  cloud    default                           -                               2025-08-25 07:28:29 UTC 
12*  cloud    gpu                               genai-####                      2025-07-21 12:55:24 UTC 
11*  cloud    pivotal-container-service-####    pivotal-container-service-####  2025-07-21 12:11:38 UTC                  
.
.
.

 

2.) Check Deployment's Last Addon Application Time.

This part is trickier. You’ll need to inspect the last successful task that ran apply-addons for the deployment.

ubuntu@####:~$ bosh -d service-instance_#### tasks --recent=999|grep 'apply-addons'|head -1

1####8 done Mon Sep  8 05:35:25 UTC 2025 Mon Sep  8 05:38:09 UTC 2025 pivotal-container-service-#### service-instance_#### run errand apply-addons from deployment service-instance_####          1 succeeded, 0 errored, 0 canceled

 

3.) Compare Timestamps.