autorestart_linux.md

description	Ways to setup auto restart for your bot on Linux hosts.

Auto-Restart on Linux

{% tabs %}

{% tab title="PM2" %} PM2 is a process manager originally intended for Node.js but can also be used with Python applications, such as our Modmail bot and Logviewer. To use pm2, we will need to install Node Package Manager (npm).

Installing pm2 Using apt (Ubuntu, Debian, etc):

sudo apt install npm -y && sudo npm i pm2 -g

Installing pm2 using dnf (Fedora, Alma Linux, etc):

sudo dnf -y install npm && sudo npm i pm2 -g

Then, in the Modmail folder, start the Modmail process in the background with:

pm2 start modmail.sh --name "modmail"

You can see the logs of your Modmail process with:

pm2 logs modmail

And then, to make sure that pm2 stays active and persistent between machine restarts, run the following commands:

pm2 save && pm2 startup

Here's some of the other PM2 commands for future reference:

pm2 restart modmail
pm2 reload modmail
pm2 stop modmail
pm2 delete modmail
pm2 list
``` {% endtab %}

{% tab title="systemd (Setting up Modmail as a Linux Service)" %} `systemd` is a built-in service manager for most Linux systems. It's primary used to manage background applications and services and to make applications auto-restart on crash and run on system startup.

We will be using `systemd` for Modmail by making a service file for our bot.

In order to create the service file, you will first need to know three things, your Linux `username`, your Modmail folder location as `modmail_path` and your Pipenv location as `pipenv_path`.

First, your Linux `username` can be fetched with the following command:

```bash
whoami

You can get your pipenv_path with:

whereis pipenv

Now, using nano, create a service file for systemd with:

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

and paste in the contents below, replacing username, modmail_path and pipenv_path with yours respectively. Ctrl+O and Enter to save. Ctrl+X to exit the nano editor.

{% code title="modmail.service" %}

[Unit]
Description=Modmail bot
After=network.target

[Service]
User=username # replace this
Group=username # replace this
Restart=always
RestartSec=10
Type=simple
WorkingDirectory=modmail_path # replace this
ExecStart=pipenv_path run python bot.py # replace pipenv_path only

[Install]
WantedBy=multi-user.target

{% endcode %}

Now, start your Modmail bot with:

sudo systemctl start modmail

If everything goes correctly, you should see your bot online. You can also view the logs of your systemd process with:

sudo journalctl -eu modmail

With that said, go ahead and enable your Modmail service to auto-restart after crash and reboot with:

sudo systemctl enable modmail

If in the future you need to stop and disable your Modmail service, you can do so with:

sudo systemctl stop modmail
sudo systemctl disable modmail
``` {% endtab %}

{% endtabs %}