How to pass arry to container.args?

[SleepyBrett]

I have a input string that i've constructed in another step that I need to use as a .container.args. How do I template that? I've tried a few things so far.

Input parameter: '["--foo","--bar","--baz"]'

Template

steps:
  - name: foo
    inputs:
      parameters:
        - name: args
    container:
      command: "/foo"
      args: {{ WHAT DO I PUT HERE }}

things that do not work:

• "{{inputs.parameters.args}}" (this passes the whole json array as one list item)
• "{{=sprig.fromJson(input.parameters.args}}" (json: cannot unmarshal string into Go struct field Container.spec.templates.container.args of type []string)
• in your documentation you suggest this args: [ "{{inputs.parameters.message}}" ] but that only works if you have a single parameter or a fixed number of parameters.

[gitsult4n]

Structurally impossible through args templating and that is by design not a missing feature

Argo substitutes every tag into the already serialized JSON of your template

replacementStr = strconv.Quote(replacementStr)
replacementStr = replacementStr[1:len(replacementStr)-1]

so whatever you put inside args: ["{{...}}"] becomes one escaped JSON string fragment sitting inside one array slot A three item array can never come out of a single string slot no matter what the expression resolves to which is why the sprig fromJson form fails with the same unmarshal error the value is still a string at substitution time

The supported way is podSpecPatch because that field itself is a raw string field The one level of escaping gets undone when the whole workflow JSON is parsed so a parameter holding actual JSON lands intact

podSpecPatch: '{"containers":[{"name":"main","args":{{inputs.parameters.args}}}]}'

with the parameter holding ["--foo","--bar","--baz"] end to end This is templated through processPodSpecPatch then applied as a strategic merge patch against PodSpec where containers merge by name and args gets replaced outright not appended

examples/pod-spec-from-previous-step.yaml in the repo does the identical pattern for resources so this is the intended mechanism not a workaround

If podSpecPatch is locked down in your setup the fallback is folding the whole thing into one shell string

command: [sh, -c]
args: ["{{inputs.parameters.args_as_shell_string}}"]