setting-VPS-Ubuntu

# Setting Up VPS

- accessing server
  command:
  $ ssh -i /pem/location/ [email protected]

  example :
  $ ssh -i ~/.ssh/pem/mypem.pem [email protected]

  note :
  - save pem in ~/.ssh/pem/

- create user (if needed)
  command :
  $ sudo adduser newuser

  note :
  - follow the instructions
  - one of the instructions may ask you to create password

- add user as sudoers
  command :
  $ sudo usermod -aG sudo newuser

  then try to access newuser :
  $ su - newuser
  > your console location should be changed to '[email protected]'

  then try to list '/root' directory :
  $ sudo ls -al /root

  loging out from [email protected]
  ctrl + D

- set locale
  command :
  $ sudo locale-gen en_US
  $ sudo nano /etc/environment

  add :
  LANG=en_US.UTF-8
  LC_ALL=en_US.UTF-8

  then save.

- install bash-completion, nano, xclip, and vim.
  command :
  $ sudo apt-get install bash-completion nano xclip vim


- install git  
  command :
  $ sudo apt-get install git-core curl build-essential openssl libssl-dev libxslt-dev libxml2-dev libcurl3-dev

- ssh key
  WARNING :
  —  make sure you are in the right user. In this case, we will generate ssh for newuser  that we just created before.
  — if you are not in newuser  : 
    $ su - newuser

  Generate shh :
  $ ssh-keygen -t rsa -C 4096
  > will show you this message :
  Generating public/private rsa key pair.
  Enter file in which to save the key (/root/.ssh/id_rsa):

  > type location or enter for choose default location. next :
  Enter passphrase (empty for no passphrase):
  Enter same passphrase again:

  > ssh will be generated with something like this :
  Your identification has been saved in /home/user/.ssh/id_rsa.
  Your public key has been saved in /home/user/.ssh/id_rsa.pub.
  The key fingerprint is:
  SHA256:LBKSJANDdH2c05MSvk+tOTf8zR316iAG1yvqyvE root@ip-172-30-0-180
  The key's randomart image is:
  +---[RSA 2048]----+
  |  oO=.+o ..+ .   |
  |  +o...o..* +    |
  |   .+ .  ..o .   |
  |   . . o   o .   |
  |      . S o o . .|
  |       . o o =  o|
  |      .   + B +..|
  |     . o o o + =+|
  |      ooE    .o =|
  +----[SHA256]-----+

  check your ssh_id :
  $ cat ~/.ssh/id_rsa.pub
  $ cat ~/.ssh/id_rsa
  those command will show your id_rsa.

  note :
  - '4096' in 'ssh-keygen -t rsa -C 4096' means the key size we are choosing. read more : https://www.ssh.com/ssh/keygen/#sec-Choosing-an-Algorithm-and-Key-Size
  - id_rsa is private key. id_rsa.pub is public key. make sure you ONLY share the public one. 

  Add your local-key to remote server (use multiple terminal tab)

  on server ([email protected]):
  $ cd ~/.ssh
  $ touch authorized_keys

  on local :
  $ cat ~/.ssh/id_rsa.pub
  copy the shown key

  back to server ([email protected]) :
  $ cd ~/.ssh
  $ echo 'paste-your-local-key-here' >> authorized_keys
  check :
  cat ~/.ssh/authorized_keys

  then try to access 'newuser' through your local console :
  warning! Make sure your console in local position!
  $ ssh [email protected]