Send Alerts to Slack

Option 1: 축구중계 Send Alerts to Slack

✅ Step 1: Create a Slack Incoming Webhook

Go to: https://api.slack.com/apps
Create a new app → Select "Incoming Webhooks"
Enable Webhooks and create a Webhook URL
Choose a channel (e.g., #fail2ban-alerts)
Copy the Webhook URL (you'll use it in your script)

✅ Step 2: Create the Notification Script

Create a new script file:

bash

복사편집

sudo nano /etc/fail2ban/action.d/slack.conf

Paste this template:

ini

복사편집

[Definition] actionstart = actionstop = actioncheck = actionban = curl -X POST -H 'Content-type: application/json' --data '{"text":"[Fail2Ban] IP <ip> has been banned from <name> jail."}' https://hooks.slack.com/services/XXXXXXXXX/YYYYYYYYY/ZZZZZZZZZZZZZZ actionunban = curl -X POST -H 'Content-type: application/json' --data '{"text":"[Fail2Ban] IP <ip> has been unbanned from <name> jail."}' https://hooks.slack.com/services/XXXXXXXXX/YYYYYYYYY/ZZZZZZZZZZZZZZ

Replace the webhook URL with your own.

✅ Step 3: Add to Fail2Ban Jail

In /etc/fail2ban/jail.local:

ini

복사편집

[nginx-auth] enabled = true port = http,https filter = nginx-auth logpath = /var/log/nginx/error.log maxretry = 5 bantime = 3600 findtime = 600 action = slack

Restart Fail2Ban:

bash

복사편집

sudo systemctl restart fail2ban

Now every ban/unban will notify your Slack channel with the IP and jail name.

???? Option 2: Send 축구중계 Alerts to Telegram

✅ Step 1: Set Up a Telegram Bot

Open Telegram, search for @BotFather
Create a new bot → Get the bot token
Send a message to the bot or your group
Visit:
https://api.telegram.org/bot<your_token>/getUpdates
→ This gives you your chat ID

✅ Step 2: Create Telegram Action Script

File: /etc/fail2ban/action.d/telegram.conf

ini

복사편집

[Definition] actionstart = actionstop = actioncheck = actionban = curl -s -X POST https://api.telegram.org/bot<YOUR_BOT_TOKEN>/sendMessage -d chat_id=<YOUR_CHAT_ID> -d text="[Fail2Ban] Banned IP <ip> from <name> jail." actionunban = curl -s -X POST https://api.telegram.org/bot<YOUR_BOT_TOKEN>/sendMessage -d chat_id=<YOUR_CHAT_ID> -d text="[Fail2Ban] Unbanned IP <ip> from <name> jail."

Replace <YOUR_BOT_TOKEN> and <YOUR_CHAT_ID>.

✅ Step 3: Activate the Telegram Alert

In /etc/fail2ban/jail.local:

ini

복사편집

action = telegram

Restart:

bash

복사편집

sudo systemctl restart fail2ban

Boom — you’ll now get real-time ban/unban alerts in Telegram!

???? Bonus Ideas:

Add GeoIP lookup to show country flag and location:

bash

복사편집

geoiplookup <ip>

Pipe alerts into Grafana Loki or InfluxDB for dashboards
Use Uptime Kuma alongside for service status alerts

???? Result: Real-Time Monitoring That Works

축구중계	Alert Speed	Setup Difficulty	Secure?
Slack	Instant	Easy	✅
Telegram	Instant	Moderate	✅

With these alerts, you’ll always know who’s knocking—and who got kicked out—in real-time, no matter where you are.

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