= NginX - ReverseProxy =

== Installation ==

Se référer a la documentation : ''AUF - PROCÉDURE D'INSTALLATION DU REVERSE PROXY IDNEUF''.

== Configurer un site comportant un cluster ==

Dans le fichier de configuration du site : {{{
upstream proxy-idneuf {
	ip_hash;
	server prod-drupal02-idneuf.vpc02.auf;
	server prod-drupal03-idneuf.vpc02.auf;
}

server {
	listen 80;
	listen [::]:80;

	server_name prod-prox-vip.vpc02.auf;
	#server_name prod-proxy01.vpc02.auf;
	#server_name idneuf.org;
	#server_name ori-oai.idneuf.org;

	root /var/www/html/;

        # log level
        access_log /var/log/nginx/www.idneuf.org.access;

        #error_log /var/log/nginx/www.idneuf.org.error debug; #debug
        error_log /var/log/nginx/www.idneuf.org.error; #normal

        location / {

                if ($args ~ q=user){
                        rewrite ^$ http://prod-proxy-vip.vpc02.auf/user permanent;
                }

                if ($args ~ q=admin){
                        rewrite ^$ http://prod-proxy-vip.vpc02.auf/admin permanent;
                }

                proxy_set_header Host prod-proxy-vip.vpc02.auf;
                proxy_set_header X-Real-IP $remote_addr;
                proxy_set_header X-Forwarded-For $remote_addr;
                proxy_pass http://proxy-idneuf;
        }

        location /admin {
                proxy_set_header Host prod-drupal01-idneuf.vpc02.auf;
                proxy_set_header X-Real-IP $remote_addr;
                proxy_set_header X-Forwarded-For $remote_addr;
                proxy_pass http://prod-drupal01-idneuf.vpc02.auf;
        }

        location /user {
                proxy_set_header Host prod-drupal01-idneuf.vpc02.auf;
                proxy_set_header X-Real-IP $remote_addr;
                proxy_set_header X-Forwarded-For $remote_addr;
                proxy_pass http://prod-drupal01-idneuf.vpc02.auf;
        }

	location /ressources/ {
		#try_files $uri $uri/ $uri/index.html =404;
		proxy_set_header Host prod-proxy-vip.vpc02.auf;
		proxy_set_header X-Real-IP $remote_addr;
		proxy_set_header X-Forwarded-For $remote_addr;
		proxy_pass http://prod-ori-oai01-idneuf.vpc02.auf;
	}

	location /ori-oai-thumbnail/ {
		proxy_set_header Host prod-proxy-vip.vpc02.auf;
		proxy_set_header X-Real-IP $remote_addr;
		proxy_set_header X-Forwarded-For $remote_addr;
		proxy_pass http://prod-ori-oai01-idneuf.vpc02.auf;
	}
}
}}}


L'option `ip_hash` permet de conserver la connexion de chaque client sur le même serveur.

== Keepalived ACTIF/PASSIF ==

=== Installation des paquets ===

{{{
apt-get install keepalived
}}}

=== Configuration ===

Contenu du fichier `/etc/keepalived/keepalived.conf` sur le primaire : {{{
# Global Configuration
global_defs {
	notification_email {
		root
	}
	notification_email_from keepalived@ca.auf.org
	smtp_server localhost
	smtp_connect_timeout 30
	router_id KeepAlivedProxy
	enable_script_security
}

vrrp_script chk_nginx {
	script "/usr/bin/pgrep nginx"
	interval 2
}

vrrp_instance VI_1 {
	interface eth0
	virtual_router_id 51
	state MASTER
	priority 150
	advert_int 1

	authentication {
		auth_type PASS
		auth_pass xxxxxxxx
	}

	virtual_ipaddress {
		137.74.32.196/25 dev eth1
	}
	virtual_ipaddress_excluded {
		2001:41d0:129:5700::196/64 dev eth1
	}

	track_script {
		chk_nginx
	}
}
}}}

Contenu du fichier identique sur le secondaire, à l'exception de ces lignes : {{{
	state BACKUP 
	priority 100
}}}

Ainsi, si NginX tombe ou si le serveur tombe, l'IPV(irtuelle) va être attribuée au BACKUP.

La directive STATE indique le status au démarrage de keepalived.

== Mise en maintenance du site ==

=== Définition du site de maintenance ===

Dans le fichier `/etc/nginx/sites-available/maintenance_www.idneuf.org` : {{{
server {
	listen 80 default;
	server_name www.idneuf.org;
	root /var/www/html/;
	index index.html;
}
}}}

=== Script de bascule ===

Le script maintenance_nginx.sh contient : {{{#!bash
#!/bin/bash

ALT_SITE='maintenance_www.idneuf.org'
MAIN_SITE='dev.www.idneuf.org'
BASE_A='/etc/nginx/sites-available'
BASE_E='/etc/nginx/sites-enabled'

case "$1" in
  down)
    rm $BASE_E/$MAIN_SITE
    ln -s $BASE_A/$ALT_SITE $BASE_E/$ALT_SITE
    systemctl restart nginx
    ;;
  up)
    rm $BASE_E/$ALT_SITE
    ln -s $BASE_A/$MAIN_SITE $BASE_E/$MAIN_SITE
    systemctl restart nginx
    ;;

  *)
    echo "Usage: $0 {up|down}"
    exit 1
    ;;
esac

exit 0
}}}