You can execute short-lived workflows by running them as Tasks in Kf. Tasks are run under Apps, meaning each Task must have an associated App. Each Task execution uses the build arttifacts from the parent App. Because Tasks are short-lived, the App will not be deployed as a long-running application, and no routes should be created for the App or the Task.

Push an App for running Tasks

Navigate to the directory of the App manifest or source code and create an App for running Tasks with the kf push APP_NAME --task command. The --task flag indicates that the App is meant to be used for running Tasks, and thus no routes will be created on the App and it will not be deployed as a long-running application.

 $  
kf  
push  
helloworld  
--task 

Confirm that no App instances or routes were created by listing the App.

 $  
kf  
apps
Listing  
Apps  
 in 
  
Space:  
test-space
Name  
Instances  
Memory  
Disk  
CPU  
URLs
helloworld  
stopped  
1Gi  
1Gi  
100m  
<nil> 

Run Task on App

When you run a Task on the App, you can optionally specify a start command using the --command flag. If no start command is specified, it uses the start command specified on the App. If the App doesn't have a start command specified, it looks up the CMD configuration of the container image. A start command must exists in order to run Task successfully.

 $  
kf  
run-task  
helloworld  
--command  
 "printenv" 
Task  
helloworld-gd8dv  
is  
submitted  
successfully  
 for 
  
execution. 

The Task name is automatically generated in the Kubernetes API Server. It is prefixed with the App name and surfixed with an arbitrary string. The Task name is an unique identifier for Tasks within the same cluster.

Specify Task resource limits

Resource limits (such as CPU cores/Memory limit/Disk quota) can be specified in the App (during kf push ) or during the kf run-task command. The limits specified in the kf run-task command take prededence over the limits specified on the App.

To specify resource limits in an App, you can use the --cpu-cores , --memory-limit and --disk-quota flags in the kf push command.

 $  
kf  
push  
helloworld  
--command  
 "printenv" 
  
--cpu-cores = 
 0 
.5  
--memory-limit = 
2G  
--disk-quota = 
5G  
--task 

To override these limits in the App, you can use the --cpu-cores , --memory-limit and --disk-quota flags in the kf run-task command.

 $  
kf  
run-task  
helloworld  
--command  
 "printenv" 
  
--cpu-cores = 
 0 
.5  
--memory-limit = 
2G  
--disk-quota = 
5G 

Specify a custom display name for a Task

You can optionally use the --name flag to specify a custom display name for a Task for easier identification/grouping.

 $  
kf  
run-task  
helloworld  
--command  
 "printenv" 
  
--name  
foo
Task  
helloworld-6swct  
is  
submitted  
successfully  
 for 
  
execution.

$  
kf  
tasks  
helloworld
Listing  
Tasks  
 in 
  
Space:  
 test 
  
space
Name  
ID  
DisplayName  
Age  
Duration  
Succeeded  
Reason
helloworld-6swct  
 3 
  
foo  
1m  
21s  
True  
<nil> 

Managing Tasks

View all Tasks of an App with the kf tasks APP_NAME command.

 $  
kf  
tasks  
helloworld
Listing  
Tasks  
 in 
  
Space:  
 test 
  
space
Name  
ID  
DisplayName  
Age  
Duration  
Succeeded  
Reason
helloworld-gd8dv  
 1 
  
helloworld-gd8dv  
1m  
21s  
True  
<nil> 

Cancel a Task

Cancel an active Task using the kf terminate-task command.

Cancel a Task by Task name.

 $  
kf  
terminate-task  
helloworld-6w6mz
Task  
 "helloworld-6w6mz" 
  
is  
successfully  
submitted  
 for 
  
termination 

Or cancel a Task by APP_NAME + Task ID.

 $  
kf  
terminate-task  
helloworld  
 2 
Task  
 "helloworld-6w6mz" 
  
is  
successfully  
submitted  
 for 
  
termination 

• Note: You can only cancel Tasks that are pending/running, completed Tasks are not cancellable.

Cancelled Tasks have PipelineRunCancelled status.

 $  
kf  
tasks  
helloworld
Listing  
Tasks  
 in 
  
Space:  
 test 
  
space
Name  
ID  
DisplayName  
Age  
Duration  
Succeeded  
Reason
helloworld-gd8dv  
 1 
  
helloworld-gd8dv  
1m  
21s  
True  
<nil>
helloworld-6w6mz  
 2 
  
helloworld-6w6mz  
38s  
11s  
False  
PipelineRunCancelled 

View Task logs

View logs of a Task using the kf logs APP_NAME --task command.

 $  
kf  
logs  
helloworld  
--task