# Eternal Terminal

Eternal Terminal is a remote shell that automatically reconnects without interrupting the session.

Website: <https://mistertea.github.io/EternalTerminal/>.

## Integration tests

Circle: [![CircleCI](https://circleci.com/gh/MisterTea/EternalTerminal/tree/master.svg?style=svg)](https://circleci.com/gh/MisterTea/EternalTerminal/tree/master)

Linux: ![Linux CI](https://github.com/MisterTea/EternalTerminal/workflows/Linux%20CI/badge.svg?branch=master)

## Packaging status

[![Packaging
status](https://repology.org/badge/vertical-allrepos/eternalterminal.svg)](https://repology.org/project/eternalterminal/versions)

## Installing

### macOS

The easiest way to install is using Homebrew:

```
brew install MisterTea/et/et
```

Then if you want a daemon to launch `etserver` on every boot:

On m1 (Apple Silicon) Macs:

```
sudo sed 's:/usr/local/bin/etserver:/opt/homebrew/bin/etserver:g' ../init/launchd/homebrew.mxcl.et.plist | sudo tee /Library/LaunchDaemons/homebrew.mxcl.et.plist
sudo launchctl load -w /Library/LaunchDaemons/homebrew.mxcl.et.plist
```

On x86 Macs:

```
sudo cp ../init/launchd/homebrew.mxcl.et.plist /Library/LaunchDaemons/homebrew.mxcl.et.plist
sudo launchctl load -w /Library/LaunchDaemons/homebrew.mxcl.et.plist
```


Alternatively, a package is available in MacPorts:

```
sudo port install et
```

### Ubuntu

For Ubuntu, use our PPA:

```
sudo add-apt-repository ppa:jgmath2000/et
sudo apt-get update
sudo apt-get install et
```

Or see "Debian/Ubuntu" below to install and build from source (e.g., for ARM).


### Debian

For debian, use our deb repo. For buster:

```
echo "deb https://github.com/MisterTea/debian-et/raw/master/debian-source/ buster main" | sudo tee -a /etc/apt/sources.list.d/et.list
curl -sSL https://github.com/MisterTea/debian-et/raw/master/et.gpg | sudo tee /etc/apt/trusted.gpg.d/et.gpg >/dev/null
sudo apt update
sudo apt install et
```

### CentOS 7

Up to the present day the only way to install is to [build from source](#centos-7-1).

### CentOS 8

```
sudo dnf install epel-release
sudo dnf install et
```

### FreeBSD
On FreeBSD, use:

```
pkg install eternalterminal
```

### Fedora (version 29 and later):

```
sudo dnf install et
```

### openSUSE

```
zypper ar -f obs://network
zypper ref
zypper in EternalTerminal
```

### Other Linux

Install dependencies:

* Fedora (tested on 25):

  ```
  sudo dnf install boost-devel libsodium-devel protobuf-devel \
  	protobuf-compiler cmake gflags-devel libcurl-devel
  ```

* Gentoo:

  ```
  sudo emerge dev-libs/boost dev-libs/libsodium \
  	dev-libs/protobuf dev-util/cmake dev-cpp/gflags
  ```

Download and install from source:

```
git clone --recurse-submodules https://github.com/MisterTea/EternalTerminal.git
cd EternalTerminal
mkdir build
cd build
cmake ../
make
sudo make install
```

### Windows

Eternal Terminal works under WSL (Windows Subsystem for Linux).  Follow the ubuntu instructions.

### Docker Image

See [docker/README.md](docker/)

## Verifying

Verify that the client is installed correctly by looking for the `et` executable: `which et`.

Verify that the server is installed correctly by checking the service status: `systemctl status et`.  On some operating systems, you may need to enable and start the service manually: `sudo systemctl enable --now et`.

You are ready to start using ET!

## Configuring

If you'd like to modify the server settings (e.g. to change the listening port), edit /etc/et.cfg.

## Using

ET uses ssh for handshaking and encryption, so you must be able to ssh into the machine from the client. Make sure that you can `ssh user@hostname`.

ET uses TCP, so you need an open port on your server. By default, it uses 2022.

Once you have an open port, the syntax is similar to ssh. Username is default to the current username starting the et process, use `-u` or `user@` to specify a different if necessary.
```
et hostname (etserver running on default port 2022, username is the same as current)
et user@hostname:8000 (etserver running on port 8000, different user)
```
You can specify a jumphost and the port et is running on jumphost using `-jumphost` and `-jport`. If no `-jport` is given, et will try to connect to default port 2022.
```
et hostname -jumphost jump_hostname (etserver running on port 2022 on both hostname and jumphost)
et hostname:8888 -jumphost jump_hostname -jport 9999
```
Additional arguments that et accept are port forwarding pairs with option `-t "18000:8000, 18001-18003:8001-8003"`, a command to run immediately after the connection is setup through `-c`.

Starting from the latest release, et supports parsing both user-specific and system-wide ssh config file.
The config file is required when your sshd on server/jumphost is listening on a port which is not 22.
Here is an example ssh config file showing how to setup when
- there is a jumphost in the middle
- sshd is listening on a port which is not 22
- connecting to a different username other than current one.

```
Host dev
  HostName 192.168.1.1
  User fred
  Port 5555
  ProxyJump user@jumphost.example.org:22
```

With the ssh config file set as above, you can simply call et with

```
et dev (etserver running on port 2022 on both hostname and jumphost)
et dev:8000 -jport 9000 (etserver running on port 9000 on jumphost)
```

## Building from Source

### macOS

To build Eternal Terminal on Mac, the easiest way is to grab dependencies with Homebrew:

```
brew install --only-dependencies MisterTea/et/et
git clone --recurse-submodules https://github.com/MisterTea/EternalTerminal.git
cd EternalTerminal
mkdir build
cd build
# Add if it doesn't work on Apple Silicon but should work without it
if [[ $(uname -a | grep 'arm\|aarch64') ]]; then export VCPKG_FORCE_SYSTEM_BINARIES=1; fi
cmake ../
make && sudo make install
```

To run an `et` server for testing, run `./etserver`.  To run an `et`
server daemon persistently across reboots:

```
sudo cp ../init/launchd/homebrew.mxcl.et.plist /Library/LaunchDaemons
sudo launchctl load -w /Library/LaunchDaemons/homebrew.mxcl.et.plist
```

### Debian/Ubuntu

Grab the deps and then follow this process.

Debian/Ubuntu Dependencies:

```
sudo apt install libboost-dev libsodium-dev \
	libprotobuf-dev protobuf-compiler libgflags-dev libutempter-dev libcurl4-openssl-dev \
    build-essential ninja-build cmake git zip
```

Fetch source, build and install:

```
git clone --recurse-submodules https://github.com/MisterTea/EternalTerminal.git
cd EternalTerminal
mkdir build
cd build
# For ARM (including OS/X with apple silicon):
if [[ $(uname -a | grep 'arm\|aarch64') ]]; then export VCPKG_FORCE_SYSTEM_BINARIES=1; fi
cmake ../
make package
sudo dpkg --install *.deb
sudo cp ../etc/et.cfg /etc/
```

Once built, the binary only requires `libgflags-dev` and `libprotobuf-dev`.


### CentOS 7

Install dependencies:
```
sudo yum install epel-release
sudo yum install cmake3 boost-devel libsodium-devel protobuf-devel \
     protobuf-compiler gflags-devel protobuf-lite-devel libcurl-devel \
     perl-IPC-Cmd perl-Data-Dumper libunwind-devel libutempter-devel
```

Install scl dependencies
```
sudo yum install centos-release-scl
sudo yum install devtoolset-11 devtoolset-11-libatomic-devel rh-git227
```

Download and install from source ([see #238 for details](https://github.com/MisterTea/EternalTerminal/issues/238)):
```
git clone --recurse-submodules https://github.com/MisterTea/EternalTerminal.git
cd EternalTerminal
mkdir build
cd build
scl enable devtoolset-11 rh-git227 'cmake3 ../'
scl enable devtoolset-11 'make && sudo make install'
sudo cp ../systemctl/et.service /etc/systemd/system/
sudo cp ../etc/et.cfg /etc/
```

Find the actual location of et:

	which etserver

Correct the service file (see [#180](https://github.com/MisterTea/EternalTerminal/issues/180) for details).

```
sudo sed -ie "s|ExecStart=[^[:space:]]*[[:space:]]|ExecStart=$(which etserver) |" /etc/systemd/system/et.service
```

Alternativelly, open the file /etc/systemd/system/et.service in an editor and correct the `ExectStart=...` line to point to the correct path of the `etserver` binary.

	 ExecStart=/usr/local/bin/etserver --cfgfile=/etc/et.cfg

Reload systemd configs:

```
sudo systemctl daemon-reload
```

Start the et service:

```
sudo systemctl enable --now et.service
```

## Building using Docker

Builder Dockerfiles are located at [deployment/](deployment/). Supported OSes: CentOS 8, openSUSE and Ubuntu.

## Reporting issues

If you have any problems with installation or usage, please [file an issue on github](https://github.com/MisterTea/EternalTerminal/issues).

## Developers

- Jason Gauci: https://github.com/MisterTea
- Ailing Zhang: https://github.com/ailzhang
- James Short: https://github.com/jshort