Slack Bot - Simple Python Implementation

A dead-simple Slack bot built with Bolt for Python. No Docker, no complexity, just python main.py.

Features

• /ping slash command → Responds with "Pong!"
• "hello" message listener → Detects "hello" (case-insensitive) and responds with "Hey there!"
• /add-all slash command → Adds all workspace members to the channel with confirmation

Quick Start (Local Development)

# 1. Clone and setup
cd PWRUP_slack_bot
python3 -m venv venv
source venv/bin/activate
pip install -r requirements.txt

# 2. Configure environment
cp .env.example .env
# Edit .env with your Slack tokens (see Setup Guide below)

# 3. Run the bot
python main.py

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📋 Complete Setup Guide

Step 1: Create Slack App

1. Go to https://api.slack.com/apps
2. Click "Create New App" → "From scratch"
3. Name it (e.g., "PWRUP Bot") and select your workspace
4. Click "Create App"

Step 2: Configure Bot Permissions

1. In your app settings, go to "OAuth & Permissions"

2. Scroll to "Scopes" → "Bot Token Scopes"

3. Add these scopes:

   • chat:write - Send messages
   • commands - Use slash commands
   • channels:history - Read messages in public channels
   • groups:history - Read messages in private channels
   • im:history - Read direct messages
   • mpim:history - Read group messages
   • users:read - List workspace members
   • channels:read - Read channel info
   • channels:manage - Invite users to channels
   • groups:write - Invite users to private channels

4. Scroll up and click "Install to Workspace"

5. Authorize the app

6. Copy the "Bot User OAuth Token" (starts with xoxb-)

   • Save this as SLACK_BOT_TOKEN in your .env file

Step 3: Get Signing Secret

1. Go to "Basic Information" in your app settings
2. Scroll to "App Credentials"
3. Copy the "Signing Secret"
   • Save this as SLACK_SIGNING_SECRET in your .env file

Step 4: Create Slash Commands

1. Go to "Slash Commands" in your app settings
2. Click "Create New Command" for /ping:
   • Command: /ping
   • Request URL: https://your-domain.com/slack/events
   • Short Description: "Ping the bot"
3. Click "Create New Command" for /add-all:
   • Command: /add-all
   • Request URL: https://your-domain.com/slack/events
   • Short Description: "Add all workspace members to this channel"

Step 5: Enable Event Subscriptions

1. Go to "Event Subscriptions" in your app settings
2. Toggle "Enable Events" to ON
3. Request URL: https://your-domain.com/slack/events
   • ⚠️ You need to deploy your bot first before Slack can verify this URL
4. Scroll to "Subscribe to bot events"
5. Add these events:
   • message.channels - Messages in public channels
   • message.groups - Messages in private channels
   • message.im - Direct messages
   • message.mpim - Group messages
6. Click "Save Changes"

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🚀 Ubuntu Server Deployment

Prerequisites

# Update system
sudo apt update && sudo apt upgrade -y

# Install Python 3 and pip
sudo apt install python3 python3-pip python3-venv curl -y

Deployment Steps

1. Upload Your Code

# On your Ubuntu server
cd /opt
sudo git clone https://github.com/PinewoodRobotics/SlackBot.git
cd SlackBot

# Or upload files manually with scp:
# scp -r /path/to/PWRUP_slack_bot user@your-server:/opt/SlackBot

2. Setup Python Environment

cd /opt/SlackBot
sudo python3 -m venv venv
sudo chown -R $USER:$USER venv
source venv/bin/activate
pip install -r requirements.txt

3. Configure Environment

# Create .env file
cp .env.example .env
nano .env

# Add your tokens:
# SLACK_BOT_TOKEN=xoxb-your-actual-token
# SLACK_SIGNING_SECRET=your-actual-secret
# PORT=3000

4. Test the Bot

# Run manually to test
python main.py

# You should see: ⚡️ Slack bot is starting on port 3000...
# Press Ctrl+C to stop

5. Setup Systemd Service (Run on Bot)

# Create service file
sudo nano /etc/systemd/system/slackbot.service

Paste this content:

[Unit]
Description=PWRUP Slack Bot
After=network.target

[Service]
Type=simple
User=ubuntu
WorkingDirectory=/opt/SlackBot
Environment="PATH=/opt/SlackBot/venv/bin"
EnvironmentFile=/opt/SlackBot/.env
ExecStart=/opt/SlackBot/venv/bin/python main.py
Restart=always
RestartSec=10

[Install]
WantedBy=multi-user.target

Note: Change User=ubuntu to your actual username if different.

# Enable and start the service
sudo systemctl daemon-reload
sudo systemctl enable slackbot
sudo systemctl start slackbot

# Check status
sudo systemctl status slackbot

# View logs
sudo journalctl -u slackbot -f

6. Setup Cloudflare Tunnel

# Install Cloudflare Tunnel
curl -L --output cloudflared.deb https://github.com/cloudflare/cloudflared/releases/latest/download/cloudflared-linux-amd64.deb
sudo dpkg -i cloudflared.deb
rm cloudflared.deb

# Authenticate with Cloudflare
cloudflared tunnel login

# Create a tunnel (replace 'slackbot' with your preferred name)
cloudflared tunnel create slackbot

# Get your tunnel ID from the output

Create config file at ~/.cloudflared/config.yml:

tunnel: slackbot
credentials-file: ~/.cloudflared/<YOUR-TUNNEL-ID>.json

ingress:
  - hostname: your-domain.com
    service: http://localhost:3000
  - service: http_status:404

Create systemd service for tunnel:

sudo nano /etc/systemd/system/cloudflared.service

[Unit]
Description=Cloudflare Tunnel
After=network.target

[Service]
Type=simple
User=ubuntu
ExecStart=/usr/local/bin/cloudflared tunnel --config ~/.cloudflared/config.yml run slackbot
Restart=always
RestartSec=10

[Install]
WantedBy=multi-user.target

sudo systemctl daemon-reload
sudo systemctl enable cloudflared
sudo systemctl start cloudflared
sudo systemctl status cloudflared

7. Update Slack App URLs

Now go back to your Slack app settings:

1. Event Subscriptions → Request URL: https://your-domain.com/slack/events
2. Slash Commands → /ping → Request URL: https://your-domain.com/slack/events
3. Click "Save Changes"

Slack will verify the URL (should show a green checkmark ✓)

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🧪 Testing

Test /ping Command

In any Slack channel where the bot is added:

/ping

Expected response: Pong!

Test Message Listener

In any channel where the bot is added:

hello
Hello
HELLO
hey hello there

Expected response: Hey there <@your_username>!

Test /add-all Command

In any channel where the bot is added:

/add-all

Expected: Ephemeral message (only visible to you) showing all members to be added with Confirm/Cancel buttons. Click Confirm to add them all.

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🔧 Useful Commands

# View bot logs
sudo journalctl -u slackbot -f

# Restart bot
sudo systemctl restart slackbot

# Stop bot
sudo systemctl stop slackbot

# Check bot status
sudo systemctl status slackbot

# Update code and restart
cd /opt/SlackBot
git pull
sudo systemctl restart slackbot

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🐛 Troubleshooting

Bot not responding to /ping

1. Check if service is running: sudo systemctl status slackbot
2. Check logs: sudo journalctl -u slackbot -f
3. Verify Slack slash command URL is correct
4. Make sure bot is installed in your workspace

Bot not responding to "hello"

1. Make sure bot is invited to the channel: /invite @YourBotName
2. Check Event Subscriptions are enabled
3. Verify bot has correct scopes (see Step 2)
4. Check logs for errors

"url_verification failed" error

• This happens when Slack can't verify your URL
• Make sure bot is running: sudo systemctl status slackbot
• Make sure tunnel is running: sudo systemctl status cloudflared
• Verify tunnel is connected: sudo journalctl -u cloudflared -f
• Check bot is responding: curl https://your-domain.com/slack/events

Port 3000 already in use

# Find what's using port 3000
sudo lsof -i :3000

# Kill the process or change PORT in .env

Cloudflare Tunnel issues

# Check tunnel status
sudo systemctl status cloudflared

# View tunnel logs
sudo journalctl -u cloudflared -f

# Restart tunnel
sudo systemctl restart cloudflared

# List active tunnels
cloudflared tunnel list

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📁 Project Structure

PWRUP_slack_bot/
├── main.py              # Main bot code
├── requirements.txt     # Python dependencies
├── .env.example        # Environment template
├── .env                # Your actual config (git-ignored)
├── .gitignore          # Git ignore rules
└── README.md           # This file

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🔐 Security Notes

• Never commit .env to git (it's in .gitignore)
• Keep your tokens secret
• Use HTTPS in production (handled by certbot)
• Slack automatically verifies requests using the signing secret

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📚 Resources

• Slack Bolt Python Docs
• Slack API Documentation
• Slack App Management

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🎉 That's It!

You now have a production-ready Slack bot running on your Ubuntu server. No Docker, no complexity, just Python.

Questions? Check the logs: sudo journalctl -u slackbot -f