Pass build date in build_args when building Dockerfile

[ddhanak]

Hi!

Couldn't find this anywhere but is it possible to pass build date in build_args when building a Dockerfile?

Thanks!

[taylorsilva]

You'll need to have a task generate the date in the format you want. You could output the date into a file and then use load_var to read the file into a variable that you can then pass into your build step as a param using the var format ((.:my-var))

Might look something like this:

- task: generate-date
  config:
  ...
  outputs:
  - name: todays
  run:
    path: sh
    args:
    - -cx
    - |
      date +'%Y%m%d' > todays/date
- load_var: date
  file: todays/date
- task: build-image
  config:
    ...
    params:
      ARG_DATE: ((.:date))

[Shuu-Ri]

Hi @taylorsilva ,

Sorry for asking this because I am a newbie on this. Is the one you showing a compose.yml file or a YML file with any filename?

Thanks

[taylorsilva]

@Shuu-Ri The yaml I wrote would be part of a pipeline. I wrote the steps that someone could add to their job in their pipeline yaml.

So that stuff would be part of some yaml file (pipeline.yml) and I would set it in Concourse using fly set-pipeline. Hope that helps with your understanding.

[Shuu-Ri]

That's cleared my doubts. Thanks. :D