IBM Cloud Code Engine: How to overwrite environment variable in cron-invoked job run? - ibm-cloud

Question

When working with jobs in IBM Cloud Code Engine, I would submit a jobrun for the actual invocation. For the jobrun I can specify environment variables to be passed into the runtime environment (--env FOO=BAR).
How can I do the same when using a cron subscription to trigger the job, i.e., to set FOO=BAR?

Answer 1

I believe the correct flag to pass to the CLI is the --ext or --extension.
% ibmcloud ce subscription cron create --
NAME:
create - Create a cron event subscription.
USAGE:
create --name CRON_SOURCE_NAME --destination DESTINATION_REF [options...]
OPTIONS:
--destination, -d value Required. The name of the resource that will receive events.
--name, -n value Required. The name of the cron event subscription. Use a name that is unique within the project.
--content-type, --ct value The media type of the 'data' or 'data-base64' option. Examples include 'application/json',
'application/x-www-form-urlencoded', 'text/html', and 'text/plain'.
--data, --da value The data to send to the destination.
--data-base64, --db value The base64-encoded data to send to the destination.
--destination-type, --dt value The type of the 'destination'. Valid values are 'app' and 'job'. (default: "app")
--extension, --ext value Set CloudEvents extensions to send to the destination. Must be in NAME=VALUE format. This option can be
specified multiple times. (accepts multiple inputs)
For example:
% ibmcloud ce subscription cron create -d application-5c -n sample-cron-sub --ext FOO=BAR
Creating cron event subscription 'sample-cron-sub'...
Run 'ibmcloud ce subscription cron get -n sample-cron-sub' to check the cron event subscription status.
% ibmcloud ce subscription cron get -n sample-cron-sub
Getting cron event subscription 'sample-cron-sub'...
OK
Name: sample-cron-sub
ID: xxxx
Project Name: susan-project
Project ID: xxxx
Age: 3m16s
Created: 2022-06-06T11:17:17-07:00
Destination Type: app
Destination: application-5c
Schedule: * * * * *
Time Zone: UTC
Ready: true
CloudEvents Extensions:
Name Value
FOO BAR
Events:
Type Reason Age Source Messages
Normal PingSourceSkipped 3m17s pingsource-controller PingSource is not ready
Normal PingSourceDeploymentUpdated 3m17s (x2 over 3m17s) pingsource-controller PingSource adapter deployment updated
Normal PingSourceSynchronized 3m17s pingsource-controller PingSource adapter is synchronized
After looking at this a bit more it appears that the name=value pairs you pass in to an event subscription prepend the string 'CE_' to the name.
Therefore, to allow for this in the running job, you would need to prepend the environment variable in the job with the CE_. For example:
When I create the jobdefinition I add the environment variable like this:
CE_FOO=BAR
Then, when I create the event subscription, for the --ext flag, I use the original suggestion: --ext FOO=BAR
I believe since the FOO variable in the event subscription automatically gets the prepended CE_ to the FOO variable it should work.
Please let me know if this does not work or I misunderstood you.