Slack2gram

Slack2gram is an application to forward chat messages from Slack to Telegram channels. Is supports message routing, so one single bot could be used to do forwarding for many channels. Slack2gram was developed for those, who using Slack as a primary corporate or team communication solution, but does not want to have Slack installed on their mobile devices. Using Slack2gram they can recieve Slack chat messages in Telegram channels.

How to prepare

Slack bot

• Create a new app
• Use "From an app manifest" feature and example manifest
• Click "Install to Workspace"
• On Basic Information blade, scroll down to App-Level Tokens section and click on Generate Tokens and Scopes
• Type any Token Name and select "connections:write" scope
• Click "Generate" and write down xapp token
• Go to "OAuth & Permissions" blade, and write down xoxb token
• Go to "Install App" blade and click "Reinstall to Workspace"
• Open Slack application and invite the Bot user to every channel where you want to make forward from. The Bot will unable to forward messages from any channels where it's not a member.

Telegram bot

• Open Telegram, find @BotFather, type /start
• Type /newbot to create a bot and follow instructions
• Write down API key
• Open Telegram application and add the Bot user to every channel where you want to make forward to. The Bot will unable to forward messages to any channels where it's not a member. While adding bot, you can only select a Post Messages permission.

Routing rules

Create a file routing.conf with message routing rules in following form:

<slack channel name #1>: <telegram channel id #1>
<slack channel name #2>: <telegram channel id #2>

To find an Id for telegram channel open in browser the following URL: https://api.telegram.org/bot<api_token>/getUpdates. If you can't see the channel you are looking for - just send a new message there.

How to run

From source code

• Create and activate a new Python virtual env:

python3 -m venv .venv
source .venv/bin/activate

• Install Python dependencies: pip install -r requirements.txt

• Export following environment variables:

  export SLACK_BOT_TOKEN=<xoxb-...>
  export SLACK_APP_TOKEN=<xapp-...>
  export TG_BOT_TOKEN=<0123456789:AA..>
  

• Run the code: python3 main.py

Using docker image

• Export following environment variables:

  export SLACK_BOT_TOKEN=<xoxb-...>
  export SLACK_APP_TOKEN=<xapp-...>
  export TG_BOT_TOKEN=<0123456789:AA..>

• Run the docker container:

docker run -d -v $(pwd)/routing.conf:/app/routing.conf \
-e SLACK_BOT_TOKEN=${SLACK_BOT_TOKEN} \
-e SLACK_APP_TOKEN=${SLACK_APP_TOKEN} \
-e TG_BOT_TOKEN=${TG_BOT_TOKEN} baber/slack2gram:latest