I realized that sometimes my brain isn't large enough to contain all my knowledge. So I decided to keep a list of some useful things I keep using over and over again.

/var/www

You do not want to make the whole folder accessible since those aren't good practices. The best way is to use the www-data group.

sudo mkdir ${folder name}
sudo chown -R ${user}:www-data ${folder name}

Now I can use git clone without using sudo.

PM2

For Node.js apps, simply do pm2 start name.js --name "Name"

Nginx

Making configs

Good practice is to make the configs in sites-available and create a symlink to sites-enabled. Make sure it is the absolute path

sudo ln -s source_file link_file

Syntax check and reload

sudo nginx -t
sudo systemctl reload nginx

Docker

For going into docker files with bash, do

docker exec-it [container] /bin/bash

SSH

SSH keys are a useful way to prevent single sign in passwords that could be predicted. On your local machine:

cd ~/.ssh
ssh-keygen -t rsa -b 4096 -C "[email protected]"

There's no need to input a password, although you can choose to name your key something different. Note that the command above generates 2 files: a file with the name you created, and another file with the name you created plus .pub. You can think of a public key as the lock to your door - you need to copy that to your server, and the other file is known as the private key, the key you need to safeguard on your local machine.

To make it so that the server knows how to use your public key, on your server you need to copy it to ~/.ssh/authorized_keys. You could just scp or copy and paste the contents in directly, but the easiest way is to use an in built command:

ssh-copy-id -i ~/.ssh/name_of_file.pub user@host

Why use the command from the openssh package? For instance, if you don't have the .ssh folder or the authorized_keys file, it creates it all for you, hassle free.

Now that that is done, you should be able to ssh into your server without a password.

SSH configs

This is really useful if you don't want to type out the domain or server ip whenever you ssh. To make a config file, vim ~/.ssh/config, and add this:

Host ${server_name}
User ${user}
IdentityFile ${~/.ssh/public_key_file}
HostName ~{url or ip address}

Note that the ${} is for you to substitute your own things.

This way, just call ssh server_name and you're good to go.