slack-webhook-send-message

#!/bin/bash
set -euf -o pipefail

##
# Slack.com script that uses a webhook to send a message.
#
# Syntax:
#
#     slack-webhook-send-message <url> <channel> <username> <text>
#
# Example:
#
#     slack-webhook-send-message
#       https://hooks.slack.com/services/mykey
#       myusername
#       myemoji
#       mychannel
#       "Hello World"
#
# This script uses our preferred conventions:
#
#   * It requires parameters for a user name, emoji, and channel.
#   * It logs to syslog.
#
# ## Environment Variables
#
# This script can use environment variables for command paths:
#
#   * CURL: `curl` command. Example: `CURL=/usr/bin/curl`
#
# This script can use environment variables for parameter defaults:
#
#   * SLACK_HOOK
#   * SLACK_USERNAME
#   * SLACK_EMOJI
#   * SLACK_CHANNEL
#   * SLACK_TEXT
#
# ## Future Ideas
#
# Change from positional parameters to key=val parameters.
#
# ## Contact
#
# Contact: Joel Parker Henderson (joel@joelparkerhenderson.com)
# License: GPL
# Created: 2015-09-19
# Updated: 2015-09-21
# Version: 1.1
##

hook="${1:-$SLACK_HOOK}"
username="${2:-$SLACK_USERNAME}"
emoji="${3:-$SLACK_EMOJI}"
channel="${4:-$SLACK_CHANNEL}"
text="${5:-$SLACK_TEXT}"

logger "$0 $hook $username $emoji $channel $text"
${CURL:-curl} -X POST "$hook" --data-urlencode "payload={\"username\": \"$username\", \"icon_emoji\": \"$emoji\", \"channel\": \"$channel\", \"text\": \"$text\"}"