Impact of enabling diego_docker flag on applications running in Cloud Foundry

Products

• VMware Tanzu Platform - Cloud Foundry
• VMware Tanzu Application Service

Issue/Introduction

The diego_docker flag can be enabled in Cloud Foundry to allow space developers to push Docker apps. This article provides insight on how this works and the possible effect on applications running in Cloud Foundry.

 

Resolution

Docker and garden use the same libraries to isolate and limit resources. It is important to take into account that the minimum Cloud Controller API required for this flag to be available is v2.33.

The detailed explanation of the use of Docker can be found in the following documentation:

Using Docker in TAS for VMs/ Elastic Application Runtime: https://techdocs.broadcom.com/us/en/vmware-tanzu/platform/elastic-application-runtime/6-0/eart/docker.html

 

The status of the feature flag can be checked using cf commands or the Cloud Controller API:

CF command:

cf feature-flag diego_docker

 

API:

 /v2/config/feature_flags/diego_docker

 

 

To activate or deactivate the flag you can use cf commands.

To enable the flag:

cf enable-feature-flag diego_docker

To disable the flag:

cf disable-feature-flag diego_docker

Enabling the flag has no impact on applications already running in garden, as no restart or changes occur to currently running apps. When the flag is disabled, this will cause all docker image based applications to be stopped within a few minutes.