Linux Server setup

Basic settings

In the last chapter we got familiar with the shell and a few important standard commands.

Even though the next chapter Secure Linux server would have priority for security reasons, I find the next settings quite worthwhile. We'll add a little color to the terminal, which is quite good for readability. In this chapter we will also add our domain name to the /etc/hosts file, which we will need later anyway.

At the end we restart the server, because some settings only take effect then.

Overview of settings:


Enter domain as host

Later, various services will need our domain name, which we add to the /etc/hosts file:


__$ sudo nano /etc/hosts
 

The content will look something like this:

/etc/hosts


127.0.0.1 localhost
127.0.1.1 srv1

# The following lines are desirable for IPv6 capable hosts
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters

It is a tabular listing. We add our domain name in the line starting with 127.0.1.1. We need this later for a mail service. Additionally we add localhost.localdomain at 127.0.0.1. With my domain, the full file looks like this:

/etc/hosts


127.0.0.1 localhost localhost.localdomain
127.0.1.1 linuxserversetup.com srv1

# The following lines are desirable for IPv6 capable hosts
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters

Save and close (CTRL+s, CTRL+x).


Change tab stop size

This setting is really a matter of taste. With this we can change the tab stop size in the Nano Editor. I like to set it to 2. This means that one tab corresponds to 2 spaces.

Open file ~/.nanorc:


__$ nano ~/.nanorc
 

The file should be empty. Write the following in it:


set tabsize 2
 

Save and close (CTRL+s, CTRL+x).


Activate shell colors

To better distinguish a few areas in the shell, we enable the force_color_prompt option in the ~/.bashrc file:


__$ nano ~/.bashrc
 

Search the setting #force_color_prompt. By a hash (#) the line is commented out. So we delete the hash so that it says the following:


...
force_color_prompt=yes
...
 

The complete file will look like this:

~/.bashrc


# ~/.bashrc: executed by bash(1) for non-login shells.
# see /usr/share/doc/bash/examples/startup-files (in the package bash-doc)
# for examples

# If not running interactively, don't do anything
case $- in
    *i*) ;;
      *) return;;
esac

# don't put duplicate lines or lines starting with space in the history.
# See bash(1) for more options
HISTCONTROL=ignoreboth

# append to the history file, don't overwrite it
shopt -s histappend

# for setting history length see HISTSIZE and HISTFILESIZE in bash(1)
HISTSIZE=1000
HISTFILESIZE=2000

# check the window size after each command and, if necessary,
# update the values of LINES and COLUMNS.
shopt -s checkwinsize

# If set, the pattern "**" used in a pathname expansion context will
# match all files and zero or more directories and subdirectories.
#shopt -s globstar

# make less more friendly for non-text input files, see lesspipe(1)
[ -x /usr/bin/lesspipe ] && eval "$(SHELL=/bin/sh lesspipe)"

# set variable identifying the chroot you work in (used in the prompt below)
if [ -z "${debian_chroot:-}" ] && [ -r /etc/debian_chroot ]; then
    debian_chroot=$(cat /etc/debian_chroot)
fi

# set a fancy prompt (non-color, unless we know we "want" color)
case "$TERM" in
    xterm-color|*-256color) color_prompt=yes;;
esac

# uncomment for a colored prompt, if the terminal has the capability; turned
# off by default to not distract the user: the focus in a terminal window
# should be on the output of commands, not on the prompt
force_color_prompt=yes

if [ -n "$force_color_prompt" ]; then
    if [ -x /usr/bin/tput ] && tput setaf 1 >&/dev/null; then
  # We have color support; assume it's compliant with Ecma-48
  # (ISO/IEC-6429). (Lack of such support is extremely rare, and such
  # a case would tend to support setf rather than setaf.)
  color_prompt=yes
    else
  color_prompt=
    fi
fi

if [ "$color_prompt" = yes ]; then
    PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]w\[\033[00m\]\$ '
else
    PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
fi
unset color_prompt force_color_prompt

# If this is an xterm set the title to user@host:dir
case "$TERM" in
xterm*|rxvt*)
    PS1="\[\e]0;${debian_chroot:+($debian_chroot)}\u@\h: \w\a\]$PS1"
    ;;
*)
    ;;
esac

# enable color support of ls and also add handy aliases
if [ -x /usr/bin/dircolors ]; then
    test -r ~/.dircolors && eval "$(dircolors -b ~/.dircolors)" || eval "$(dircolors -b)"
    alias ls='ls --color=auto'
    #alias dir='dir --color=auto'
    #alias vdir='vdir --color=auto'

    alias grep='grep --color=auto'
    alias fgrep='fgrep --color=auto'
    alias egrep='egrep --color=auto'
fi

# colored GCC warnings and errors
#export GCC_COLORS='error=01;31:warning=01;35:note=01;36:caret=01;32:locus=01:quote=01'

# some more ls aliases
alias ll='ls -alF'
alias la='ls -A'
alias l='ls -CF'

# Add an "alert" alias for long running commands.  Use like so:
#   sleep 10; alert
alias alert='notify-send --urgency=low -i "$([ $? = 0 ] && echo terminal || echo error)" "$(history|tail -n1|sed -e '''s/^s*[0-9]+s*//;s/[;&|]s*alert$/>

# Alias definitions.
# You may want to put all your additions into a separate file like
# ~/.bash_aliases, instead of adding them here directly.
# See /usr/share/doc/bash-doc/examples in the bash-doc package.

if [ -f ~/.bash_aliases ]; then
    . ~/.bash_aliases
fi

# enable programmable completion features (you don't need to enable
# this, if it's already enabled in /etc/bash.bashrc and /etc/profile
# sources /etc/bash.bashrc).
if ! shopt -oq posix; then
  if [ -f /usr/share/bash-completion/bash_completion ]; then
    . /usr/share/bash-completion/bash_completion
  elif [ -f /etc/bash_completion ]; then
    . /etc/bash_completion
  fi
fi

Save and close (CTRL+s, CTRL+x).


Restart server

To apply the settings made above, a new login is actually sufficient. However, the change of the hostname needs a restart.

Restart the server with the following command:


__$ sudo reboot
 

This will end the session and as soon as the server is up again, we can log back in via SSH. This may take a few minutes. After the next login you should see the new hostname and some more color.

The reboot doesn't take a minute and we have to connect again.