Script to comment on GitHub from a CircleCI build

circleci_comment_on_github.sh

#!/bin/sh

{ # Prevent execution if this script was only partially downloaded

# NOTE: This script will use the GitHub Personal token stored in GITHUB_AUTH_TOKEN
#       to post a comment from CircleCI to your pull request (or commit if there
#       is no pull request).
#
#       The message must be provided in /tmp/comment
#
#       This is a less sophisticated replacement for:
#       https://github.com/themadcreator/circle-github-bot

set -e

# NOTE: replace newlines by \n and " by \"
body=$(cat /tmp/comment | sed -e ':a' -e 'N' -e '$!ba' -e 's/\n/\\n/g;s/"/\\"/g')

if [ -n "$CIRCLE_PULL_REQUEST" ]; then
	location=$(echo $CIRCLE_PULL_REQUEST | grep -Po 'github.com/\K[^/]+/[^/]+')
	curl -s -u ${GITHUB_AUTH_TOKEN:?}:x-oauth-basic --data '{"body":"'"$body"'"}' \
		https://api.github.com/repos/$location/issues/${CIRCLE_PULL_REQUEST##*/}/comments
else
	curl -s -u ${GITHUB_AUTH_TOKEN:?}:x-oauth-basic --data '{"body":"'"$body"'"}' \
		https://api.github.com/repos/${CIRCLE_PROJECT_USERNAME:?}/${CIRCLE_PROJECT_REPONAME:?}/commits/${CIRCLE_SHA1:?}/comments
fi

}

Example Usage:

- run:
    name: Run tests
    command: |
      (
        echo '### Test Results'
        echo '```none'
        <<<run_test_command_here>>>
        echo '```'
      ) > /tmp/comment
      curl -sSL https://gist.githubusercontent.com/cecton/538ce1a6e0b645bd6cbbecf6ccf51366/raw/de93dfdf7182c07eebbfa258ca5a38a0c8149e01/circleci_comment_on_github.sh | sh -