use pandoc action from pandoc repo instead of local path (#180)

* use pandoc action from pandoc repo instead of local path

* reference action by exact commit

* reference render by full filepath

* add note about commit hash of reusable action

Author: chrisfenner

.github/actions/render/action.yml

@@ -1,3 +1,8 @@
+# Reminder: Due to the way GitHub Actions treats reusable workflows that use reusable actions from local paths,
+# we have to update .github/workflows/render.yml to point to a particular commit of this file.
+# This means that when updating this file, we have to first send a PR that updates the action,
+# then second send a PR send that uses the action in the reusable workflow.
+
 name: 'Render'
 description: 'Render a TCG Markdown document'
 inputs:

.github/workflows/render.yml

@@ -76,10 +76,15 @@ jobs:
           key: latex-${{ inputs.input }}-${{ inputs.container-version }}-${{ github.run_id }}
           restore-keys: latex-${{ inputs.input }}-${{ inputs.container-version }}
 
+      # Note: It appears that we can't pass variables into 'uses:' below to allow callers to
+      # request a version of the action. Referencing it by local path breaks external workflows
+      # that call to this one.
+      # The unfortunate workaround is for this file to be updated to point at specific commits
+      # and reference that version of the action file in this reusable workflow.
       # Render the document with diffs in the 'pr' mode.
       - name: Render
         if: inputs.workflow == 'pr'
-        uses: ./.github/actions/render
+        uses: trustedcomputinggroup/pandoc/.github/actions/render@8f79b567c9dc6b15afba5d83d61e0d37f9508c47
         with:
           input-md: ${{ inputs.input }}
           output-basename: ${{ steps.gen_output_name.outputs.OUTPUT_FILENAME }}
@@ -90,7 +95,7 @@ jobs:
       # Render the document with diffs in the 'manual' mode.
       - name: Render
         if: inputs.workflow == 'manual'
-        uses: ./.github/actions/render
+        uses: trustedcomputinggroup/pandoc/.github/actions/render@8f79b567c9dc6b15afba5d83d61e0d37f9508c47
         with:
           input-md: ${{ inputs.input }}
           output-basename: ${{ steps.gen_output_name.outputs.OUTPUT_FILENAME }}
@@ -99,7 +104,7 @@ jobs:
       # Render the document without diffs in other modes.
       - name: Render
         if: inputs.workflow != 'pr' && inputs.workflow != 'manual'
-        uses: ./.github/actions/render
+        uses: trustedcomputinggroup/pandoc/.github/actions/render@8f79b567c9dc6b15afba5d83d61e0d37f9508c47
         with:
           input-md: ${{ inputs.input }}
           output-basename: ${{ steps.gen_output_name.outputs.OUTPUT_FILENAME }}