slackr

#!/bin/bash

WEBHOOK_URL=""

usage() { echo "Usage: $(basename "$0") [options] <text>

Options:
    -r <channel name|channel ID>
    -i <bot icon emoji>
    -n <bot name>
    -c <good|warning|danger|#hex color>
    -a <author name>
    -t <title text>
    -l <title link URL>
    -f <footer text>
    -w <webhook URL>

Examples:
    $(basename "$0") some text
    $(basename "$0") -c good -n friendlybot -i :cat: hello
    $(basename "$0") -r general < logfile.txt
    ls -la /etc/ | $(basename "$0") -r D024BE91L -f \"\$(history 1)\"
    tail /var/log/syslog | $(basename "$0") -a \"\$(id -un) \$(hostname -f)\"
" 1>&2; exit 1; }

json_escape () {
    printf '%s' "$1" | python -c 'import json,sys; print(json.dumps(sys.stdin.read()))'
}

recipient=""
boticon=""
botname=""
color=""
authorname=""
title=""
titlelink=""
footer=""
while getopts ":r:i:n:c:a:t:l:f:w:" o; do
    case "${o}" in
        r)
            recipient="\"channel\":$(json_escape "${OPTARG}"),"
            ;;
        i)
            boticon="\"icon_emoji\":$(json_escape "${OPTARG}"),"
            ;;
        n)
            botname="\"username\":$(json_escape "${OPTARG}"),"
            ;;
        c)
            color="\"color\":$(json_escape "${OPTARG}"),"
            ;;
        a)
            authorname="\"author_name\":$(json_escape "${OPTARG}"),"
            ;;
        t)
            title="\"title\":$(json_escape "${OPTARG}"),"
            ;;
        l)
            titlelink="\"title_link\":$(json_escape "${OPTARG}"),"
            ;;
        f)
            footer="\"footer\":$(json_escape "${OPTARG}"),"
            ;;
        w)
            WEBHOOK_URL="${OPTARG}"
            ;;
        *)
            echo "Illegal option: ${OPTARG}"$'\n'
            usage
            ;;
    esac
done
shift $((OPTIND-1))

if [[ "$WEBHOOK_URL" == "" ]]; then
    echo "No webhook URL specified. Please set WEBHOOK_URL in $(readlink -f "$0") or use the -w option."$'\n'
    usage
fi

text=$*
if [[ "$text" == "" ]]; then
    if [ -t 0 ]; then
        echo "No text specified"$'\n'
        usage
    else
        while IFS= read -r line || [ -n "$line" ]; do
            text="$text$line"$'\n'
        done
    fi
fi

payload="payload={$recipient$boticon$botname\"attachments\":[{$color$authorname$title$titlelink$footer\"text\":$(json_escape "\`\`\`$text\`\`\`"),\"mrkdwn_in\":[\"text\"]}]}"

echo "$(curl -s -S --data-urlencode "$payload" "$WEBHOOK_URL" 2>&1)"