hadolint_output is empty

[pascalgulikers]

- uses: jbergstroem/hadolint-gh-action@v1
  id: hadolint
  with:
    dockerfile: ./Dockerfile
    #output_format: sarif

- name: Debug
  shell: bash
  run: |
    echo "${{ steps.hadolint.outputs.hadolint_version }}"
    echo "${{ steps.hadolint.outputs.hadolint_gh_action_version }}"
    echo "${{ steps.hadolint.outputs.hadolint_output }}"

Produces:
Run echo "2.12.0"
echo "2.12.0"
echo "1.12.0"
echo ""

In other words: the hadolint_output output variable is empty, no matter which output_format is specified.
It looks like it's being caused by:

hadolint-gh-action/lib/main.sh

Line 52 in 4683c5d

echo "hadolint_output=${OUTPUT//$'\n'/'%0A'} >> \$GITHUB_OUTPUT"

Possible solution:
change
echo "hadolint_output=${OUTPUT//$'\n'/'%0A'} >> \$GITHUB_OUTPUT"
to
echo "hadolint_output=${OUTPUT//$'\n'/'%0A'}" >> "${GITHUB_OUTPUT}"

[jbergstroem]

Thanks for the bug report. Will look at it tonight!

[jbergstroem]

Was able to repro with the draft PR as a e2e test. Here's the problem:

++ eval hadolint --no-fail --no-color '' -f json test/fixtures/Dockerfile-warning
+++ hadolint --no-fail --no-color -f json test/fixtures/Dockerfile-warning
+ OUTPUT='[{"code":"DL3018","column":1,"file":"test/fixtures/Dockerfile-warning","level":"warning","line":3,"message":"Pin versions in apk add. Instead of `apk add <package>` use `apk add <package>=<version>`"}]'
+ echo 'hadolint_output=[{"code":"DL3018","column":1,"file":"test/fixtures/Dockerfile-warning","level":"warning","line":3,"message":"Pin versions in apk add. Instead of `apk add <package>` use `apk add <package>=<version>`"}] >> /dev/null'
hadolint_output=[{"code":"DL3018","column":1,"file":"test/fixtures/Dockerfile-warning","level":"warning","line":3,"message":"Pin versions in apk add. Instead of `apk add <package>` use `apk add <package>=<version>`"}] >> /dev/null

Note: the e2e test is incorrect as well.

[jbergstroem]

Been chasing this for a bit. I believe that parsing %0A (newline escaping) might have changed in github actions.

[pascalgulikers]

Any update on this?

[jbergstroem]

Any update on this?

Been busy with work; will make an re-attempt at the fix this week. Sorry for the delay.

[pascalgulikers]

Sorry, is there any update on this?