Passing vars using reusable workflow with no success - github-actions

Question

We try to pass some env variables using a workaround to the reusable workflow as follows, but no variables are passed.
Workflow YAML is:
name: "call my_reusable_workflow"
on:
workflow_dispatch:
env:
env_branch: ${{ github.head_ref }}
env_workspace: ${{ github.workspace }}
jobs:
call_reusable_workflow_job:
uses: my_github/my-reusable-workflow-repo/.github/workflows/used_wf_test.yml#master
with:
env_vars: |
hello-to=Meir
branch_name=${{ env.env_branch }}
secrets:
my_token: ${{secrets.ENVPAT}}
and the reusable workflow YAML is:
name: my_reusable_workflow
on:
workflow_call:
inputs:
env_vars:
required: true
type: string
description: list of vars and values
secrets:
giraffe_token:
required: true
jobs:
reusable_workflow_job:
runs-on: ubuntu-latest
steps:
- name: set environment variables
if: ${{ inputs.env_vars }}
run: |
for env in "${{ inputs.env_vars }}"
do
printf "%s\n" $env >> $GITHUB_ENV
done
When the action is running it gets the value of hello-to=Meir but doesn't get the value branch_name=${{ env.env_branch }}.
I tried to pass the value also as branch_name=${{ github.head_ref }} but with no success.

Answer 1

According to the Limitations of Reusing workflows:
Any environment variables set in an env context defined at the workflow level in the caller workflow are not propagated to the called workflow. For more information, see "Variables" and "Contexts."
So, the env context is not supported in reusable workflow callers at the moment.
However, you can pass the Default Environment Variables to reusable workflow callers.
For example, in your particular scenario, you want to use these contexts:
github.head_ref
github.workspace
The equivalent default environment variables are:
GITHUB_HEAD_REF
GITHUB_WORKSPACE
And, your reusable workflow (e.g. reusable_workflow_set_env_vars.yml) will be called by its caller (e.g. reusable_workflow_set_env_vars_caller.yml) like this:
name: reusable_workflow_set_env_vars_caller
on:
workflow_dispatch:
jobs:
set-env-vars:
uses: ./.github/workflows/reusable_workflow_set_env_vars.yml
with:
env_vars: |
TEST_VAR='test var'
GITHUB_HEAD_REF=$GITHUB_HEAD_REF
GITHUB_WORKSPACE=$GITHUB_WORKSPACE
GITHUB_REF=$GITHUB_REF
Apart from that, regarding your implementation of the reusable workflow (e.g. reusable_workflow_set_env_vars.yml):
As the env_vars is of string type, you need to somehow solidify it against YAML multiline whitespace variants e.g. >.
You can visualize and observe whitespace on this online utility (https://yaml-multiline.info/).
With the current implementation, there may be word splitting for variable values containing spaces in them. So, you might need to iterate per line i.e. up to the newline character. This thread (https://superuser.com/questions/284187/bash-iterating-over-lines-in-a-variable) might be helpful for this.