nginx-proxy

#!/bin/bash
# /usr/local/bin/nginx-proxy
# Copyright (C) 2015, John Carver <dude4linux@gmail.com>

  # This program is free software: you can redistribute it and/or modify
  # it under the terms of the GNU General Public License as published by
  # the Free Software Foundation, either version 3 of the License, or
  # (at your option) any later version.

  # This program is distributed in the hope that it will be useful,
  # but WITHOUT ANY WARRANTY; without even the implied warranty of
  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  # GNU General Public License at (http://www.gnu.org/licenses/) for
  # more details.

PROGNAME=$(basename $0)
VERSION="2.3"

info() { echo "INFO: $@"; }
fatal() { echo "FATAL: $@" 1>&2; exit 2; }

usage() {
cat <<EOF
${PROGNAME} version ${VERSION}: GNU General Public License version 3
Create site configuration to proxy requests destined for domain to host

Syntax: ${PROGNAME} [-d|--domain] domain [-n|--name] host [-r|--remove]

Arguments::

    domain           source domain (fqdn)
    host             destination host name

Options::

    -h --help        usage: display this message
    -d --domain      source domain
    -n --name        host name
    -l --list        list domains and hosts
    -r --remove      remove a proxy from domain(s) to host
    -t --template    use alternate template
    -c --check       indicate if any changes would be made

Examples::

    # create a proxy from domain 'www.example.com' to host 'wordpress' 
    ${PROGNAME} --domain www.example.com --name wordpress

    # remove a proxy from domain 'www.example.com' to host 'wordpress'
    ${PROGNAME} --remove -d www.example.com -n wordpress

    # remove all proxies for host 'wordpress'
    ${PROGNAME} --remove -d all -n wordpress

    # run in check-mode making no changes, but indicating what would be changed
    ${PROGNAME} --check -d www.example.com -n wordpress

Exit Codes::

        0    no changes were made or would have been made (check-mode)
        1    changes were made or would have been made (check-mode)
        2    fatal error prevented command completion

Notes::

    # also supports the v13.0 syntax
    ${PROGNAME} www.example.com wordpress

    # uses Jinja2 style templates for variable substitution
    # default template (preconfigured for ports 80, 443)
    /etc/nginx/templates/default.j2

    # lxc template (preconfigured for ports 80, 443, 12320, 12321, 12322)
    /etc/nginx/templates/container.j2

EOF
}

wait_for_host() {
    # wait for host name resolution
    # it does not mean that host is up
    local hostname="$1"
    local retries="${2:-10}"
    local delay="${3:-3}"

    for (( i=1; i<=${retries}; i++ )); do
        host ${hostname} > /dev/null && return 0
        sleep ${delay}
    done
    return 1
}

## remove proxy
remove_proxy() {
  local changed=0

  # domain_cert and domain_key are considered placeholders
  # which may have been replaced by registered certs/keys
  # therefore we don't routinely remove them
  domain_cert="/etc/ssl/certs/${domain}.pem"
  domain_key="/etc/ssl/private/${domain}.key"

  site_enabled="/etc/nginx/sites-enabled/${domain}"
  site_available="/etc/nginx/sites-available/${domain}"

  [ -f ${site_enabled} ]   && changed=1
  [ -f ${site_available} ] && changed=1

  if [ ${changed} -eq 1  ]; then
    if [ ${check} -eq 0 ]; then
      rm -f ${site_enabled}
      rm -f ${site_available}

      # remove domain entry from hosts.conf
      sed -i "/^${proxy_ip}\s*${domain}/ d" ${hosts}

      info "removed ${domain} proxy ${name}"
    else
      info "check-mode: would have removed ${domain} proxy ${name}"
    fi
  else
    if [ ${check} -eq 0 ]; then
      info "no change: ${domain} proxy ${name} does not exist"
    else
      info "check-mode: no change: ${domain} proxy ${name} does not exist"
    fi
  fi
  return ${changed}
}

## create proxy
create_proxy() {
  local changed=0

  domain_cert="/etc/ssl/certs/${domain}.pem"
  domain_key="/etc/ssl/private/${domain}.key"
  site_enabled="/etc/nginx/sites-enabled/${domain}"
  site_available="/etc/nginx/sites-available/${domain}"

  [ -f ${site_enabled} ]    || changed=1
  [ -f ${site_available} ]  || changed=1
  [ -f ${domain_cert} ]     || changed=1
  [ -f ${domain_key} ]      || changed=1

  if [ ${changed} -eq 1 ]; then
    if [ ${check} -eq 0 ]; then
      # if domain certificate doesn't exist, create one
      [ -f ${domain_cert} ] || turnkey-make-ssl-cert ${domain}
      [ -f ${domain_cert} ] || fatal "can't find ${domain_cert}"
      [ -f ${domain_key} ]  || fatal "can't find ${domain_key}"

      cp  ${template_dir}/${template} ${site_available}
      sed -i "s|{{ nginx_domain_name }}|${domain}|;\
              s|{{ nginx_proxy_host }}|${name}|;\
              s|{{ nginx_domain_cert }}|${domain_cert}|;\
              s|{{ nginx_domain_key }}|${domain_key}|" ${site_available}

      [ -e "${site_enabled}" ]  || ln -s ${site_available} ${site_enabled}

      # add domain entry to hosts.conf
      grep -q "^${proxy_ip}\s\+${domain}" ${hosts} || printf "%-18s %s\n" ${proxy_ip} ${domain} >> ${hosts}

      info "created ${domain} proxy ${name}"
    else
      info "check-mode: would have created ${domain} proxy ${name}"
    fi
  else
    if [ ${check} -eq 0 ]; then
      info "${domain} proxy ${name} exists, no change required"
    else
      info "check-mode: ${domain} proxy ${name} exists, no change required"
    fi
  fi
  return ${changed}
}

## list proxies
list_proxies() {
  local name
  local domain

  for site in ${sites}/*; do
    domain=$(basename ${site})
    [ "${domain}" == "default" ] && continue
    name=$(sed -n "0,/proxy_pass/ s|^.*proxy_pass.*://\(.*\)/\?;.*$|\1|p" ${site})
    if [ "${name}" != "" ]; then
     printf "%-20s %s\n" ${domain} ${name}
    fi
  done
}

# vars
sites="/etc/nginx/sites-available"
hosts="/etc/hosts.dnsmasq"
proxy_ip="$(hostname -I | awk '/$/ { print $1 }')"
template_dir="/etc/nginx/templates"
template="default.j2"

# if lxc appliance, use container template
[[ "$(turnkey-version)" =~ "turnkey-lxc" ]] && template="container.j2"

remove=0
check=0

# must have one or more arguments
if [ $# -eq 0 ]; then
    usage
    exit 2
fi

while [[ -n $1 ]]; do
    case "$1" in
        -h|--help)      usage; exit 0 ;;
        -d|--domain)    domain="$2"; shift ;;
        -n|--name)      name="$2"; shift ;;
        -l|--list)      list_proxies; exit 0 ;;
        -r|--remove)    remove=1 ;;
        -t|--template)  template="$2"; shift ;;
        -c|--check)     check=1 ;;
         *)             domain="$1"; name="$2"; shift 2; break ;;
    esac
    shift
done

# should only have zero arguments here, 
# domain and container name must not be null
if [[ $# -ne 0 || -z "${domain}" || -z "${name}" ]]; then
  usage
  exit 2
fi

changed=0

if [ ${remove} -eq 1 ]; then
  if [ "${domain}" = 'all' ]; then
    allsites=$( grep -Rl "proxy_pass *https\?://${name}" ${sites} )
    if [[ $allsites ]]; then
      for domain in $( echo $allsites | xargs -n1 basename | sort -u ); do
        remove_proxy || changed=1
      done
    fi
  else
    remove_proxy || changed=1
  fi
else
  # prepare to create proxy
  # make sure template exists
  [ -e "${template_dir}/${template}" ] || fatal "does not exist: ${template}"

  # check to see if host exists
  wait_for_host ${name}
  if [ $? -ne 0 ]; then
    if [ ${check} -eq 0 ]; then
      fatal "can't create proxy; host ${name} doesn't exist"
    else
      info "check-mode: can't create proxy; host ${name} doesn't exist"
      exit 0
    fi
  fi
  create_proxy || changed=1
fi 

service dnsmasq reload
service nginx reload
exit ${changed}