How might I run Pandoc 'convert all files in Dir' command in Github Actions

Question

I would like to setup a github action that runs this command from pandoc FAQ on a repo when its pushed to master. Our objective is to convert all md files in our repo from md to another format using the pandoc docker container.

here is where I got so far. In the first example i do not declare an entrypoint and i get the error "/usr/local/bin/docker-entrypoint.sh: exec: line 11: for: not found."

name: Advanced Usage

on:
  push:
    branches:
      - master

jobs:
  convert_via_pandoc:
    runs-on: ubuntu-18.04
    steps:
      - name: convert md to rtf
        uses: docker://pandoc/latex:2.9
        with:
          args: |
            for f in *.md; do pandoc "$f" -s -o "${f%.md}.rtf"; done

In the second example we declare entrypoint: /bin/sh and the result is error "/bin/sh: can't open 'for': No such file or directory"

name: Advanced Usage

on:
  push:
    branches:
      - master

jobs:
  convert_via_pandoc:
    runs-on: ubuntu-18.04
    steps:
      - name: convert md to rtf
        uses: docker://pandoc/latex:2.9
        with:
          entrypoint: /bin/sh
          args: |
            for f in *.md; do pandoc "$f" -s -o "${f%.md}.rtf"; done

I am a total noob to git actions and not a technical person so my guess is this is easy idea for the SO community. just trying some simple workflow automation. any explicit and beginner feedback is appreciated. thanks - allen

Answer 1

I needed to do a recursive conversion of md files to make a downloadable pack, so this answer extends beyond the OP's goal.

This github action will:

1. Make the output directory (mkdir output)
2. Recurse through the folders, create similarly named folders in an output directory (for d in */; do mkdir output/$d; done)
3. Find all md files recursively (find ./ -iname '*.md' -type f) and execute a pandoc command (-exec sh -c 'pandoc ${0} -o output/${0%.md}.docx' {} \;)

Note that you have to be careful with double and single quote marks when converting from stuff that works in terminal to things that get correctly transformed into a single docker command as part of the github action.

First iteration

jobs:
  convert_via_pandoc:
    runs-on: ubuntu-20.04
    steps:
      - uses: actions/checkout@v2
      - name: convert md to docx
        uses: docker://pandoc/latex:2.9
        with:
          entrypoint: /bin/sh
          args: -c "mkdir output;for d in */; do mkdir output/$d; done;find ./ -iname '*.md' -type f -exec sh -c 'pandoc ${0} -o output/${0%.md}.docx' {} \;"
      - uses: actions/upload-artifact@master
        with:
          name: output
          path: output

This solution was developed using @anemyte's info and this SO post on recursive conversion

Second iteration from @caleb

name: Generate Word docs
on: push

jobs:
  convert_via_pandoc:
    runs-on: ubuntu-20.04
    container:
      image: docker://pandoc/latex:2.9
      options: --entrypoint=sh
    steps:
      - uses: actions/checkout@v2
      - name: prepare output directories
        run: |
          for d in */; do
            mkdir -p output/$d
          done
      - name: convert md to docx
        run: |
          find ./ -iname '*.md' -type f -exec sh -c 'pandoc ${0} -o output/${0%.md}.docx' {} \;
      - uses: actions/upload-artifact@master
        with:
          name: output
          path: output