difference behavior of {{= workflow.creationTimestamp }} and {{ workflow.creationTimestamp }}

[roy-ht]

Summary

What happened/what you expected to happen?

{{= workflow.creationTimesamp }} should be rfc3339 string, but outputs a map representation like:

map[A:Monday B:October H:06 I:06 L:.000 M:11 S:08 Y:2021 Z:UTC a:Mon b:Oct d:11 m:10 p:AM s:1633932668 y:21 z:+0000]

some investigations

In Template.Replace,

I guess simpleReplace searches flattened replaceMap and good, but expressionReplace has a "nested" replaceMap, as env,
so the key workflow.creationTimestamp becomes a map[string]interface{}.

I'd like to get a formatted string value or time.Time instance to send sprig.dateModify like:

{{= sprig.dateModify("-24h", sprig.toDate('2006-01-02T15:04:05Z07:00', workflow.creationTimestamp)) }}

Or more simply to send to dateModify,
I would appreciate if Argo WF has workflow.creationTimestamp.time or asTime(workflow.creationTimestamp).

What version of Argo Workflows are you running?

v3.1.8

Diagnostics

Either a workflow that reproduces the bug, or paste you whole workflow YAML, including status, something like:

apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
  generateName: steps-
spec:
  entrypoint: hello

  templates:
  - name: hello
    steps:
    - - name: h1
        template: whalesay
        arguments:
          parameters:
          - name: message
            value: "1: {{ workflow.creationTimestamp }}"
    - - name: h2
        template: whalesay
        arguments:
          parameters:
          - name: message
            value: "2: {{= workflow.creationTimestamp }}"
    - - name: h3
        template: whalesay
        arguments:
          parameters:
          - name: message
            value: "3: {{= string(workflow.creationTimestamp) }}"

  - name: whalesay
    inputs:
      parameters:
      - name: message
    container:
      image: docker/whalesay
      command: [cowsay]
      args: ["{{inputs.parameters.message}}"]

What Kubernetes provider are you using?

Amazon EKS

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[alexec]

This is because workflows.creationTimestamp is, in fact, a map. It has some fields,

workflow.creationTimestamp. Creation timestamp formatted with a strftime format character

https://strftime.org

I'm not sure this is useful to most users.

Options:

1. Remove workflows.creationTimestamp.STRFTIMECHAR from expression template support (breaking change).
2. Add workflows.creationTimestamp.RFC3339 or similar.

This is an easy change.

[roy-ht]

@alexec Thanks for quick reply!

First, Option 2 seems to be good for me, but I'm not sure which is the best option for the future of Argo WF.

I prefer option 1 and add some utility function to manipulate a date (like strftime, date_add, ....), but it has a cost to existing users and need some extra implementation.

[ziv-codefresh]

@alexec i would be happy to contribute it. can you assign it to me please?

[posquit0]

I need this feature also. :)