# Helpful Linux Commands (Nginx, Pm2, Nano, Docker)

# LINUX COMMANDS

- **COPY** 
	- `cp index.js node-server/` to the directory
	- `cp index.js main.js` to the current directory
- **Restart:**  `sudo reboot`
- **Update-Upgrade** `sudo apt-get update`  `sudo apt-get upgrade` 
- **Switch User** `su - afozbek`
- **User Add** `useradd afozbek-simple`
	- `adduser afozbek`
- **List Users** `nano /etc/passwd`
- **Delete User** `deluser —remove-home newuser`
- **Add Password to User** `passwd afozbek-simple`
- **Add SSH KEY** `sudo nano ~/.ssh/authorized_keys`
- **Change SSH Config** `sudo nano /etc/ssh/sshd_config`
- **Enable Firewall** `sudo ufw enable`
	- **List** `sudo ufw app list`
		- * **Nginx Full**: This profile opens both port 80 (normal, unencrypted web traffic) and port 443 (TLS/SSL encrypted traffic)
		* **Nginx HTTP**: This profile opens only port 80 (normal, unencrypted web traffic)
		* **Nginx HTTPS**: This profile opens only port 443 (TLS/SSL encrypted traffic)
* **Look for System is Working Properly**
	* `sudo systemctl status sshd`
	* `sudo systemctl restart ssh`
* **Look Memory Usage**	
    * `free -h`
    * `vmstat -s`

## NGINX (LIKE APACHE) - Reverse Proxy

[What is a Reverse Proxy Server? | NGINX](https://www.nginx.com/resources/glossary/reverse-proxy-server/)
- **Stop** `sudo systemctl stop nginx`
- **Restart** `service nginx restart`
- **Start** `sudo systemctl start nginx`
	-  Default HTML location: `/var/www/html`
- `/etc/nginx`: The Nginx configuration directory. All of the Nginx configuration files reside here.
* `/etc/nginx/nginx.conf` The main Nginx configuration file. This can be modified to make changes to the Nginx global configuration.
	* Access Log: `/var/log/nginx/access.log`
	* Error Log: `/var/log/nginx/error.log`
* `/etc/nginx/sites-available/`: The directory where per-site “server blocks” can be stored. Nginx will not use the configuration files found in this directory unless they are linked to the sites-enabled directory (see below). 
* `/etc/nginx/sites-enabled/`: The directory where enabled per-site “server blocks” are stored. 
* `/etc/nginx/snippets`: This directory contains configuration fragments that can be included elsewhere in the Nginx configuration.

## PM2
[PM2 - Single Page Doc](https://pm2.keymetrics.io/docs/usage/pm2-doc-single-page/)
- `pm2 stop app_name_or_id`
- `pm2 list`
- `pm2 info app`
- To Start All instance on startup `pm2 startup ubuntu`

## Nano
1. `CTRL + 6` for Mark Set and mark what you want (the end could do some extra help).
2. `ALT + 6` copy selected line
3. `CTRL + K` for cutting what you want to copy
4. `CTRL + U` for pasting what you have just cut because you just want to copy.
5. `CTRL + U` at the place you want to paste.

## DOCKER
[How To Install and Use Docker on Ubuntu 18.04 | DigitalOcean](https://www.digitalocean.com/community/tutorials/how-to-install-and-use-docker-on-ubuntu-18-04)
1. Add User to Docker Group `sudo usermod -aG docker username`
2. Check User is in the Docker Group `id -nG`
3. To view system-wide information about Docker, use: `docker info`
4. Find and download(if not exist) an image from Docker Hub: `docker run {image}`
	1. Ex: `docker run hello-world`
5. Search and list images : `docker search {image}`
	1. Ex: `docker search ubuntu`
6. Run a Container and switch to the **interactive terminal(-it)**
	1. `docker run -it ubuntu`
7. Listing containers
	1. List running containers  `docker ps`
	2. List stopped containers `docker ps -f “status=exited”`
	3. List all containers `docker ps -a`
	4. View latest container `docker ps -l`
8. Start or Stop a container with its **containerId**
	1.  `docker start {containerId}`
	2. `docker stop {containerId}`
9. Remove a container  with its **containerId** or **name**
	1. `docker rm {containerId}`
	2. `docker rm {name}`
10. Remove an image with its **imageId** or **name**
	1. `docker rmi {imageId}`
	2. `docker rmi {name}`
11. Start a container with giving a custom name with **—name**
	1. `docker run --name newName {imageName}`
12. Manage your changes
	1. Commit: `docker commit -m "added Node.js" -a "{userName}" {containerId} "{userName}"/{newImageName}`
	2. Push `docker push {userName}/{imageName}`
13. Listing the Docker images - (You can see your new image there 😁)
	1. `docker images`
14. Login to Docker Hub
	1. `docker login -u {docker-registry-username}`