ttyd - Share your terminal over the web

ttyd is a simple command-line tool for sharing terminal over the web, inspired by GoTTY.

Features

• Built on top of Libwebsockets with C for speed
• Fully-featured terminal based on Xterm.js with CJK (Chinese, Japanese, Korean) and IME support
• SSL support based on OpenSSL
• Run any custom command with options
• Basic authentication support and many other custom options
• Cross platform: macOS, Linux, FreeBSD, OpenWrt/LEDE

Installation

Install on macOS

Install with homebrew:

brew install ttyd

Install on Linux

Ubuntu 16.04 as example:

sudo apt-get install cmake g++ pkg-config git vim-common libwebsockets-dev libjson-c-dev libssl-dev
git clone https://github.com/tsl0922/ttyd.git
cd ttyd && mkdir build && cd build
cmake ..
make && make install

NOTE: You may need to compile libwebsockets from source for ubuntu versions old than 16.04, since they have outdated libwebsockets-dev package (Issue #6).

Install on OpenWrt/LEDE

opkg install ttyd

NOTE: This may only works for LEDE snapshots currently, if the install command fails, compile it yourself.

Usage

Command-line Options

ttyd is a tool for sharing terminal over the web

USAGE:
    ttyd [options] <command> [<arguments...>]

VERSION:
    1.2.1

OPTIONS:
    --port, -p              Port to listen (default: 7681, use `0` for random port)
    --interface, -i         Network interface to bind
    --credential, -c        Credential for Basic Authentication (format: username:password)
    --uid, -u               User id to run with
    --gid, -g               Group id to run with
    --signal, -s            Signal to send to the command when exit it (default: SIGHUP)
    --reconnect, -r         Time to reconnect for the client in seconds (default: 10)
    --readonly, -R          Do not allow clients to write to the TTY
    --client-option, -t     Send option to client (format: key=value), repeat to add more options
    --check-origin, -O      Do not allow websocket connection from different origin
    --once, -o              Accept only one client and exit on disconnection
    --ssl, -S               Enable SSL
    --ssl-cert, -C          SSL certificate file path
    --ssl-key, -K           SSL key file path
    --ssl-ca, -A            SSL CA file path for client certificate verification
    --debug, -d             Set log level (0-9, default: 7)
    --version, -v           Print the version and exit
    --help, -h              Print this text and exit

Example Usage

ttyd starts web server at port 7681 by default, you can use the -p option to change it, the command will be started with arguments as options. For example, run:

ttyd -p 8080 bash -x

Then open http://localhost:8080 with a broswer, you will get a bash shell with debug mode enabled.

More Examples:

• If you want to login with your system accounts on the web broswer, run ttyd login.
• You can even run a none shell command like vim, try: ttyd vim, the web broswer will show you a vim editor.
• Sharing single process with multiple clients: ttyd tmux new -A -s ttyd vim, run tmux new -A -s ttyd to connect to the tmux session from terminal.

SSL how-to

Generate SSL CA and self signed server/client certificates:

# CA certificate (FQDN must be different from server/client)
openssl genrsa -out ca.key 4096
openssl req -new -x509 -days 365 -key ca.key -out ca.crt
# server certificate
openssl req -newkey rsa:2048 -nodes -keyout server.key -out server.csr
openssl x509 -req -days 365 -in server.csr -CA ca.crt -CAkey ca.key -set_serial 01 -out server.crt
# client certificate (the p12/pem format may be useful for some clients)
openssl req -newkey rsa:2048 -nodes -keyout client.key -out client.csr
openssl x509 -req -days 365 -in client.csr -CA ca.crt -CAkey ca.key -set_serial 02 -out client.crt
openssl pkcs12 -export -clcerts -in client.crt -inkey client.key -out client.p12
openssl pkcs12 -in client.p12 -out client.pem -clcerts

Then start ttyd:

ttyd --ssl --ssl-cert server.crt --ssl-key server.key --ssl-ca ca.crt bash

You may want to test the client certificate verification with curl:

curl --insecure --cert client.p12[:password] -v https://localhost:7681

If you don't want to enable client certificate verification, remove the --ssl-ca option.

Docker and ttyd

Docker containers are jailed environments which are more secure, this is useful for protecting the host system, you may use ttyd with docker like this:

• Sharing single docker container with multiple clients: docker run -it --rm -p 7681:7681 tsl0922/ttyd.
• Creating new docker container for each client: ttyd docker run -it --rm ubuntu.

Credits

• GoTTY: ttyd is a port of GoTTY to C language with many improvements.
• Libwebsockets: is used to build the websocket server.
• Xterm.js: is used to run the terminal emulator on the web, hterm is used previously.