Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/binwiederhier/replbot

Slack/Discord bot for running interactive REPLs and shells from a chat.
https://github.com/binwiederhier/replbot

discord discord-bot discordgo docker go golang repl slack slack-bot slack-bot-go

Last synced: about 1 month ago
JSON representation

Slack/Discord bot for running interactive REPLs and shells from a chat.

Awesome Lists containing this project

README

        

# 🤖 REPLbot
[![Release](https://img.shields.io/github/release/binwiederhier/replbot.svg?color=success&style=flat-square)](https://github.com/binwiederhier/replbot/releases/latest)
[![Go Reference](https://pkg.go.dev/badge/heckel.io/replbot.svg)](https://pkg.go.dev/heckel.io/replbot)
[![Tests](https://github.com/binwiederhier/replbot/workflows/test/badge.svg)](https://github.com/binwiederhier/replbot/actions)
[![Go Report Card](https://goreportcard.com/badge/github.com/binwiederhier/replbot)](https://goreportcard.com/report/github.com/binwiederhier/replbot)
[![codecov](https://codecov.io/gh/binwiederhier/replbot/branch/master/graph/badge.svg?token=bdrFZttMsk)](https://codecov.io/gh/binwiederhier/replbot)
[![Slack channel](https://img.shields.io/badge/slack-@gophers/binwiederhier-success.svg?logo=slack)](https://gophers.slack.com/archives/C01JMTPGF2Q)

REPLbot is a bot for Slack and Discord that allows you to control a [REPL](https://en.m.wikipedia.org/wiki/Read%E2%80%93eval%E2%80%93print_loop)
or shell from a chat. It comes with a few REPLs (Go 🥳, Java, NodeJS, PHP, Python, Ruby, Scala, Kotlin, C++, Ubuntu, Debian, Alpine, Arch Linux, Amazon Linux, CentOS & Fedora),
but you can [easily make or bring your own](config/script.d).

![replbot demo](assets/slack-php-count.gif)

## Why ...?
I thought it might be a fun way to collaboratively dabble with a REPL in a team. Yes, I could have gone for a terminal
in a browser, but there's nothing like having it right there in Slack. Mainly I did it because it was fun though. 😄

## How it works
I use `tmux` and the `tmux capture-pane` command to run most of the show. It's simple, but effective. In the first
iteration I tried using a pseudo terminal (pty) directly, but with all the escape sequences and commands, it was getting
kinda tiresome, and I was spending time with stuff that I didn't want to spend time with (though I learned a lot!).
And `tmux` does its job so well.

The actual REPLs are just simple scripts (see [script.d folder](config/script.d)), so they could be anything you like.
I highly recommend using Docker to provide somewhat of an isolation, though you'll probably still need to trust the
people using the bot if you give them an entire REPL.

## Screenshots & Videos







Scala, split mode (Discord)
Ubuntu running `htop` (Discord)
C++, channel mode (Discord)







Blinking cursors, choo choo 🚂 (Slack)
Custom shells, multiple sessions (Slack)

## Usage
After [installing REPLbot](#installation), you may use it by tagging `@replbot` in Slack/Discord. For the most part it
should be pretty self-explanatory:

![replbot mention](assets/slack-mention-help.png)

To start a session with the default settings, simply say `@replbot java` to start a Java REPL. There are a few advanced arguments
you can use when starting a session.

### REPL scripts
REPLbot can run more or less arbitrary scripts and interact with them -- they don't really have to be REPLs. Any interactive
script is perfectly fine, whether it's a REPL or a Shell or even a game. By default, REPLbot ships with a [few REPLs](config/script.d).
To extend the REPLs you can run, simple add more scripts in the `script-dir` folder (see [config.yml](config/config.yml)).

Here's a super simple example script:
```bash
#!/bin/sh
# Scripts are executed as "./script run " to start the REPL, and as "./script kill "
# to stop it. Not all scripts need the "kill" behavior, if they exit properly on SIGTERM.
case "$1" in
run)
while true; do
echo -n "Enter name: "
read name
echo "Hello $name!"
done
;;
*) ;;
esac
```

In all likelihood, you'll want more isolation by running REPLs as Docker containers. Here's the [PHP REPL script](https://github.com/binwiederhier/replbot/blob/1460ddba1adbfd450465d5d37b0b9b340e8a4f79/config/script.d/php)
that REPLbot ships with (not shortened):

```bash
#!/bin/sh
# REPLbot script to run a PHP REPL.
#
# Scripts are executed as "./script run " to start the REPL,
# and as "./script kill " to stop it.

DIR="$(cd -- "$(dirname "$0")" >/dev/null 2>&1 && pwd -P)"
case "$1" in
run) docker run --rm --name "$2" -it php ;;
kill) "$DIR"/helpers/docker-kill "$2" ;;
*) echo "Syntax: $0 (run|kill) ID"; exit 1 ;;
esac
```

### Session commands
When a session is started, you can get a list of available commands by typing `!help` (or `!h`). To exit a session at any
point in time, type `!exit` (or `!q`).

![replbot session help](assets/slack-session-help.png)

### Recording sessions
Sessions can be recorded using `asciinema`, and can even be automatically uploaded to either [asciinema.org](https://asciinema.org/)
or your private [asciinema-server](https://github.com/asciinema/asciinema-server) (see [install instructions](https://github.com/asciinema/asciinema-server/wiki/Installation-guide)).

After a session exits, the recording is then attached to chat as a ZIP file and optionally as a link to the asciinema server.
This behavior can be controlled by the `default-record` and `upload-recording` option in the [config.yml](config/config.yml)
file, as well as the `record`/`norecord` option when starting a session.

Here's [the asciinema.org link](https://asciinema.org/a/MGsOv6CCVXiRtR8ZEd7MtFOTe) of the example
I recorded, as well as the [ZIP archive](assets/slack-recording.zip) with the recording.

![replbot session recording](assets/slack-recording.png)

### Web terminal
Entering commands via Slack or Discord can be quite cumbersome, so REPLbot provides a web-based terminal (powered by
the amazingly awesome [ttyd](https://github.com/tsl0922/ttyd)). If enabled, a unique link is created for each session,
which provides a read-only or writable web terminal.

![replbot web terminal](assets/slack-web-terminal.png)

This behavior can be controlled by the `default-web` option in the [config.yml](config/config.yml) file, as well
as the `web`/`noweb` option when starting a session. While a session is running, it can be toggled using the `!web`
command.

![replbot web terminal](assets/web-terminal.png)

### Terminal sharing
You can share your local terminal window in Slack or Discord using the `share` feature. It's quite cool, although it's
really got nothing to do with REPLs 🤷. It also has to be specifically configured in the [config.yml](config/config.yml)
file using the `share-host` option, since it needs direct communication between the client and REPLbot.

![replbot terminal sharing](assets/slack-terminal-sharing.gif)

### Control mode
You can specify if you want the session to be started in the main channel (`channel`), in a thread (`thread`),
or in split mode (`split`) using both channel and thread. Split mode is the default because it is the cleanest to use:
it'll use a thread for command input and the main channel to display the terminal.

![replbot split mode](assets/slack-split-mode.png)

### Terminal size
You can set the terminal window size when you start a session by using the keywords `tiny` (60x15), `small` (80x24),
`medium` (100x30), and `large` (120x38). The default is `small`. You may also resize the terminal while the session is
running using the `!resize` command.

![replbot window size](assets/discord-window-size.png)

### Window mode
When starting a session, you can choose whether to trim empty space from the terminal session (`trim`), or
whether to show the entire terminal window as it would appear in a terminal emulator (`full`). The default is `full`,
as `trim` mode can get awkward when the terminal is expanded and the collapsed again.

![replbot window mode](assets/discord-window-mode.png)

## Installation
Please check out the [releases page](https://github.com/binwiederhier/replbot/releases) for binaries and
deb/rpm packages.

**Requirements**:
- A modern-ish Linux, preferably Ubuntu 18.04+, since that's what I develop on -- though it also runs on other
distros.
- [tmux](https://github.com/tmux/tmux) >= 2.6 is required, which is part of Ubuntu 18.04 (but surprisingly not part of Amazon Linux!)
- [docker](https://docs.docker.com/get-docker/) for almost all scripts REPLbot ships with
- [asciinema](https://asciinema.org/) if you'd like to [record sessions](#recording-sessions)
- [ttyd](https://github.com/tsl0922/ttyd) if you'd like to use the [web terminal](#web-terminal) feature

**Creating a REPLbot Slack app**:
REPLbot requires a Slack "Classic App (bot)", because of its use of the real time messaging (RTM)
API. To create a classic app and acquire a Slack bot token, follow these steps:
1. Create a [classic Slack app](https://api.slack.com/apps?new_classic_app=1)
2. In the "App Home" section, add a "Legacy bot user"
3. In the "OAuth & Permissions" section, click "Install to Workspace" (_this may require workspace admin approval_)
4. Copy the "Bot User OAuth Token" starting with "xoxb-..."

**Creating a REPLbot Discord app**:
1. Create a [Discord app](https://discord.com/developers/applications)
2. In the "Bot" section, click "Add Bot" and disable "Public Bot"
3. In the "OAuth2" section, click "Add Redirect" and type a URL (even https://google.com is fine),
select the scopes "bot" and "messages.read", and the permissions "public threads", "private thread",
"send messages", "manage messages", "manage threads". Click "Save changes".
4. Copy the OAuth2 URL and navigate to it in the browser and authorize the app.
5. In the "Bot" section, copy the token and paste it here

**Installing `replbot`**:
1. Make sure `tmux` and probably also `docker` are installed. Then install REPLbot using any of the methods below.
2. Then edit `/etc/replbot/config.yml` to add Slack or Discord bot token. REPLbot will figure out which one is which based on the format.
3. Review the scripts in `/etc/replbot/script.d`, and make sure that you have Docker installed if you'd like to use them.
4. If you're running REPLbot as non-root user (such as when you install the deb/rpm), be sure to add the `replbot` user to the `docker` group: `sudo usermod -G docker -a replbot`.
5. Then just run it with `replbot` (or `systemctl start replbot` when using the deb/rpm).

### Binaries and packages
**Debian/Ubuntu** (*from a repository*)**:**
```bash
curl -sSL https://archive.heckel.io/apt/pubkey.txt | sudo apt-key add -
sudo apt install apt-transport-https
sudo sh -c "echo 'deb [arch=amd64] https://archive.heckel.io/apt debian main' > /etc/apt/sources.list.d/archive.heckel.io.list"
sudo apt update
sudo apt install replbot asciinema
```

**Debian/Ubuntu** (*manual install*)**:**
```bash
sudo apt install tmux
wget https://github.com/binwiederhier/replbot/releases/download/v0.6.4/replbot_0.6.4_amd64.deb
dpkg -i replbot_0.6.4_amd64.deb
```

**Fedora/RHEL/CentOS:**
```bash
# Make sure that "tmux" is installed
rpm -ivh https://github.com/binwiederhier/replbot/releases/download/v0.6.4/replbot_0.6.4_amd64.rpm
```

**Docker:**
You can configure the Docker image by mounting a config directory (containing [config.yml](config/config.yml)) to
`/etc/replbot`. To be able to use most of the pre-packaged [script.d](config/script.d) REPLs (to be mounted to `/etc/replbot/script.d`),
you'll need to give the REPLbot image access to the Docker socket file. This allows the container to spin up other containers
on the host. This is a security risk and considered bad practice, but it's the only way.

```bash
# Config and scripts live on the host
wget https://github.com/binwiederhier/replbot/archive/refs/tags/v0.6.4.tar.gz
tar zxvf v0.6.4.tar.gz
sudo mkdir /etc/replbot
sudo cp -a replbot-0.6.4/config/{script.d,config.yml} /etc/replbot
vi /etc/replbot/config.yml
# Configure at least "bot-token"
# To support web terminal, set "web-host" (e.g. to localhost:31001)
# To support sharing, set "share-host" (e.g. to localhost:31002)

# Then you can start the REPLbot docker image (assuming web-host listening
# at 31001 and share-host at 31002)
docker run --rm -it \
-v /etc/replbot:/etc/replbot \
-v ~/.asciinema:/root/.config/asciinema \
-v /var/run/docker.sock:/var/run/docker.sock \
-p 31001:31001 \
-p 31002:31002 \
binwiederhier/replbot
```

Please note that if you'd like to associate the asciinema videos to an account, you need to set up and map the config directory
properly. For me, that worked by installing it on the host, running `asciinema rec` once and then associating the install-id
located in `~/.asciinema/install-id`. Inside the docker image, asciinema expects the config directory to be in `~/.config/asciinema`.

**Go:**
```bash
# Be sure "tmux" is installed
go get -u heckel.io/replbot
```

**Manual install** (*any x86_64-based Linux*)**:**
```bash
# Make sure that "tmux" is installed
wget https://github.com/binwiederhier/replbot/releases/download/v0.6.4/replbot_0.6.4_linux_x86_64.tar.gz
sudo tar -C /usr/bin -zxf replbot_0.6.4_linux_x86_64.tar.gz replbot
```

## Building
Building replbot is simple. Here's how you do it:

```
make build-simple
# Builds to dist/replbot_linux_amd64/replbot
```

To build releases, I use [GoReleaser](https://goreleaser.com/). If you have that installed, you can run `make build` or
`make build-snapshot`.

## Contributing
I welcome any and all contributions. Just create a PR or an issue, or talk to me [on Slack](https://gophers.slack.com/archives/C02ABHKDCN7).

## License
Made with ❤️ by [Philipp C. Heckel](https://heckel.io), distributed under the [Apache License 2.0](LICENSE).

Third party tools/libraries:
* [tmux](https://github.com/tmux/tmux) (ISC) is used to run most of the show
* [docker](https://docs.docker.com/get-docker/) is used for almost all scripts REPLbot ships with
* [asciinema](https://asciinema.org/) (GPLv3) is used to record sessions
* [ttyd](https://github.com/tsl0922/ttyd) (MIT) is used to run the web terminal
* [github.com/urfave/cli/v2](https://github.com/urfave/cli/v2) (MIT) is used to drive the CLI
* [discord-go](https://github.com/bwmarrin/discordgo) (BSD-3) is used for the Discord communication, specifically these two
[these](https://github.com/bwmarrin/discordgo/pull/922) [two](https://github.com/bwmarrin/discordgo/pull/982) pull requests
for thread support
* [slack-go](https://github.com/slack-go/slack) (BSD-2) is used for the Slack communication
* [gliderlabs/ssh](https://github.com/gliderlabs/ssh) (BSD-3) is used for remote port forwarding for terminal sharing
* [stretchr/testify](http://github.com/stretchr/testify) (MIT) is used in most of the tests

Code and posts that helped:
* [tmux sharing across hosts](https://gist.github.com/QuAzI/b6d29fd6239ed72c9c61870e7ee5ff90), thanks to [QuAzI](https://gist.github.com/QuAzI)