Simple Slack notifications sample that can be used in GitLab, when you want to send notifications under certain conditions

slack.sh

#!/usr/bin/env bash
# Simple Slack notifications that can be used in GitLab, when you want to send notifications under certain conditions
#
# SLACK_HOOK - url to slack IncomingWebhook
# ENVIRONMENT - app name
# CI_* - env vars from GitLab
#
# --error flag sends the error message.

set -e
ARG=$1
if [ "${ARG}" == "--error" ]; then
    echo Sending error message to Slack
    curl -X POST \
      ${SLACK_HOOK} \
      -H 'Content-Type: application/json' \
      -d '{"attachments": [
            {
                "fallback": "Deployment of '"${ENVIRONMENT}"' app failed! Check what went wrong here: '"${CI_PIPELINE_URL}"'",
                "pretext": ":disappointed: Sorry to say this, but...",
                "title": "'"${ENVIRONMENT}"'",
                "title_link": "'"${CI_PROJECT_URL}"'/-/jobs/'"${CI_JOB_ID}"'",
                "text": "Deployment of '"${ENVIRONMENT}"' app failed! Click on the link to see what went wrong.",
                "color": "#992222"
            },
            {
                "fallback": "Commit: '"${CI_COMMIT_SHA}"'",
                "text": "*Commit* `'"${CI_COMMIT_SHA}"'`\n*Message*\n'"${CI_COMMIT_MESSAGE}"'",
                "color": "#333333"
            }
        ]
    }'
else
    echo Sending success message to Slack
    curl -X POST \
      ${SLACK_HOOK} \
      -H 'Content-Type: application/json' \
      -d '{"attachments": [
            {
                "fallback": "Deployment of '"${ENVIRONMENT}"' app went well! It'\''s available here: '"${SLACK_URL}"'",
                "pretext": ":tada: Hey, I'\''ve got some good news for you!",
                "title": "'"${ENVIRONMENT}"'",
                "title_link": "'"${SLACK_URL}"'",
                "text": "Deployment of '"${ENVIRONMENT}"' app went well! Click on the link to see it.",
                "color": "#7CD197"
            },
            {
                "fallback": "Commit: '"${CI_COMMIT_SHA}"'",
                "text": "*Commit* `'"${CI_COMMIT_SHA}"'`\n*Message*\n'"${CI_COMMIT_MESSAGE}"'",
                "color": "#333333"
            }
        ]
    }'
fi