If you have previously used Apache you should now about a2ensite tool. If you start using nginx you probably find out that there are no such tool for nginx.

You can use following command to do that:

ln -s /etc/nginx/sites-available/mysite /etc/nginx/sites-enabled/mysite

and then restart nginx

sudo service nginx restart

But... I have found one small script that can do that for you. Also, it can display list of all available or enabled sites, disable site and automatically restart nginx.

Just put that script in /usr/bin/nginx_site and make it executable (chmod +x /usr/bin/nginx_site)

#!/bin/bash

##
#  File:
#    nginx_modsite
#  Description:
#    Provides a basic script to automate enabling and disabling websites found
#    in the default configuration directories:
#      /etc/nginx/sites-available and /etc/nginx/sites-enabled
#    For easy access to this script, copy it into the directory:
#      /usr/local/sbin
#    Run this script without any arguments or with -h or --help to see a basic
#    help dialog displaying all options.
##

# Copyright (C) 2010 Michael Lustfield <mtecknology@ubuntu.com>

# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.

##
# Default Settings
##

NGINX_CONF_FILE="$(awk -F= -v RS=' ' '/conf-path/ {print $2}' <<< $(nginx -V 2>&1))"
NGINX_CONF_DIR="${NGINX_CONF_FILE%/*}"
NGINX_SITES_AVAILABLE="$NGINX_CONF_DIR/sites-available"
NGINX_SITES_ENABLED="$NGINX_CONF_DIR/sites-enabled"
SELECTED_SITE="$2"

##
# Script Functions
##

ngx_enable_site() {
    [[ ! "$SELECTED_SITE" ]] &&
        ngx_select_site "not_enabled"

    [[ ! -e "$NGINX_SITES_AVAILABLE/$SELECTED_SITE" ]] && 
        ngx_error "Site does not appear to exist."
    [[ -e "$NGINX_SITES_ENABLED/$SELECTED_SITE" ]] &&
        ngx_error "Site appears to already be enabled"

    ln -sf "$NGINX_SITES_AVAILABLE/$SELECTED_SITE" -T "$NGINX_SITES_ENABLED/$SELECTED_SITE"
    ngx_reload
}

ngx_disable_site() {
    [[ ! "$SELECTED_SITE" ]] &&
        ngx_select_site "is_enabled"

    [[ ! -e "$NGINX_SITES_AVAILABLE/$SELECTED_SITE" ]] &&
        ngx_error "Site does not appear to be \'available\'. - Not Removing"
    [[ ! -e "$NGINX_SITES_ENABLED/$SELECTED_SITE" ]] &&
        ngx_error "Site does not appear to be enabled."

    rm -f "$NGINX_SITES_ENABLED/$SELECTED_SITE"
    ngx_reload
}

ngx_list_site() {
    echo "Available sites:"
    ngx_sites "available"
    echo "Enabled Sites"
    ngx_sites "enabled"
}

##
# Helper Functions
##

ngx_select_site() {
    sites_avail=($NGINX_SITES_AVAILABLE/*)
    sa="${sites_avail[@]##*/}"
    sites_en=($NGINX_SITES_ENABLED/*)
    se="${sites_en[@]##*/}"

    case "$1" in
        not_enabled) sites=$(comm -13 <(printf "%s\n" $se) <(printf "%s\n" $sa));;
        is_enabled) sites=$(comm -12 <(printf "%s\n" $se) <(printf "%s\n" $sa));;
    esac

    ngx_prompt "$sites"
}

ngx_prompt() {
    sites=($1)
    i=0

    echo "SELECT A WEBSITE:"
    for site in ${sites[@]}; do
        echo -e "$i:\t${sites[$i]}"
        ((i++))
    done

    read -p "Enter number for website: " i
    SELECTED_SITE="${sites[$i]}"
}

ngx_sites() {
    case "$1" in
        available) dir="$NGINX_SITES_AVAILABLE";;
        enabled) dir="$NGINX_SITES_ENABLED";;
    esac

    for file in $dir/*; do
        echo -e "\t${file#*$dir/}"
    done
}

ngx_reload() {
    read -p "Would you like to reload the Nginx configuration now? (Y/n) " reload
    [[ "$reload" != "n" && "$reload" != "N" ]] && invoke-rc.d nginx reload
}

ngx_error() {
    echo -e "${0##*/}: ERROR: $1"
    [[ "$2" ]] && ngx_help
    exit 1
}

ngx_help() {
    echo "Usage: ${0##*/} [options]"
    echo "Options:"
    echo -e "\t<-e|--enable> <site>\tEnable site"
    echo -e "\t<-d|--disable> <site>\tDisable site"
    echo -e "\t<-l|--list>\t\tList sites"
    echo -e "\t<-h|--help>\t\tDisplay help"
    echo -e "\n\tIf <site> is left out a selection of options will be presented."
    echo -e "\tIt is assumed you are using the default sites-enabled and"
    echo -e "\tsites-disabled located at $NGINX_CONF_DIR."
}

##
# Core Piece
##

case "$1" in
    -e|--enable)    ngx_enable_site;;
    -d|--disable)   ngx_disable_site;;
    -l|--list)  ngx_list_site;;
    -h|--help)  ngx_help;;
    *)      ngx_error "No Options Selected" 1; ngx_help;;
esac

Usage:
To list all the sites

$ sudo nginx_site -l

To enable site "website" (config should already exists in /etc/nginx/sites-available)

$ sudo nginx_site -e website

To disable site "website"

$ sudo nginx_site -d website