Editing KeepAlived

== Balansare IP cu KeepAlived pe Ubuntu 2X.04 LTS ==
[[File:Keepalived.png|782x782px|none|Keepalived]]

Pentru instalare keepalived se cere uneori (depinzand de ditributie si/sau versiune) instalarea librariei libipset13
<code class="mw-code mw-highlight plainlinks" style="display:block"><!--
-->apt install -y keepalived libipset13
</code>

Pe fiecare dintre noduri se creaza si editeaza urmatorul fisier:
<code class="mw-code mw-highlight plainlinks" style="display:block"><!--
-->nano /etc/keepalived/keepalived.conf
</code>
cu urmatorul continut

===== ha01 =====
<code class="mw-code mw-highlight plainlinks" style="display:block"><!--
-->vrrp_instance VIP {
&nbsp;&nbsp;state MASTER
&nbsp;&nbsp;interface ens18
&nbsp;&nbsp;virtual_router_id 66
&nbsp;&nbsp;priority 99
&nbsp;&nbsp;advert_int 1
&nbsp;&nbsp;unicast_src_ip 192.168.14.11
&nbsp;&nbsp;unicast_peer {
&nbsp;&nbsp;&nbsp;&nbsp;192.168.14.22
&nbsp;&nbsp;&nbsp;&nbsp;192.168.14.33
&nbsp;&nbsp;}
&nbsp;&nbsp;authentication {
&nbsp;&nbsp;&nbsp;&nbsp;auth_type PASS
&nbsp;&nbsp;&nbsp;&nbsp;auth_pass <span style="color:#f00">[pass1234]</span>
&nbsp;&nbsp;}
&nbsp;&nbsp;virtual_ipaddress {
&nbsp;&nbsp;&nbsp;&nbsp;192.168.14.123/24
&nbsp;&nbsp;}
}
</code>

===== ha02 si ha03 =====
<code class="mw-code mw-highlight plainlinks" style="display:block"><!--
-->vrrp_instance VIP {
&nbsp;&nbsp;state BACKUP
&nbsp;&nbsp;interface ens18
&nbsp;&nbsp;virtual_router_id 66
&nbsp;&nbsp;priority 97 <span style="color:#f00"><- pentru ha02</span>
&nbsp;&nbsp;priority 95 <span style="color:#f00"><- pentru ha03</span>
&nbsp;&nbsp;advert_int 1
&nbsp;&nbsp;unicast_src_ip 192.168.14.22 <span style="color:#f00"><- pentru ha02</span>
&nbsp;&nbsp;unicast_src_ip 192.168.14.33 <span style="color:#f00"><- pentru ha03</span>
&nbsp;&nbsp;unicast_peer {
&nbsp;&nbsp;&nbsp;&nbsp;192.168.14.11
&nbsp;&nbsp;&nbsp;&nbsp;192.168.14.33 <span style="color:#f00"><- pentru ha02</span>
&nbsp;&nbsp;&nbsp;&nbsp;192.168.14.22 <span style="color:#f00"><- pentru ha03</span>
&nbsp;&nbsp;}
&nbsp;&nbsp;authentication {
&nbsp;&nbsp;&nbsp;&nbsp;auth_type PASS
&nbsp;&nbsp;&nbsp;&nbsp;auth_pass <span style="color:#f00">[pass1234]</span>
&nbsp;&nbsp;}
&nbsp;&nbsp;virtual_ipaddress {
&nbsp;&nbsp;&nbsp;&nbsp;192.168.14.123/24
&nbsp;&nbsp;}
}
</code>
===== Legenda =====
'''vrrp_instance''' = numele instantei de VIP<br>
'''state''' = numele NIC-ului fizic sau virtual<br>
'''virtual_router_id''' = este un ID ce se aloca instantei respective (keepalived poate balansa mai multe IP-uri de pe mai multe NIC-uri)<br>
'''priority''' = reprezinta prioritatea serverului respectiv in lantul de redundanta<br>
'''advert_int''' = intervalul (secunde) in care se face verificarea celoralte instante de VIP<br>
'''unicast_src_ip''' = se trece IP-ul NIC-ului de pe serverul curent<br>
'''unicast_peer''' = se trec IP-urile celorlalte servere din instanta<br>
'''auth_pass''' = parola de maxim opt caractere persistenta pe toate instantele<br>
'''virtual_ipaddress''' = identifica IP-ul flotant de pe instantele de keepalived

== Monitorizarea Apache2 in vederea balansarii IP-ului ==

In vederea migrarii IP-ului in cazul unui fail al Apache2, se adauga urmatorul continut in toate serverele pe care instanta de Keepalived este configurata:

* nano /etc/keepalived/keepalived.conf
===== ha01, ha02 si ha03 =====
<code class="mw-code mw-highlight plainlinks" style="display:block"><!--
--><span style="color:#f00">vrrp_track_process trkap2 {
&nbsp;&nbsp;process apache2
&nbsp;&nbsp;weight 10
}</span>
vrrp_instance VIP {
&nbsp;&nbsp;state MASTER
&nbsp;&nbsp;interface ens18
&nbsp;&nbsp;virtual_router_id 66
&nbsp;&nbsp;priority 99
&nbsp;&nbsp;advert_int 1
&nbsp;&nbsp;unicast_src_ip 192.168.14.11
&nbsp;&nbsp;unicast_peer {
&nbsp;&nbsp;&nbsp;&nbsp;192.168.14.22
&nbsp;&nbsp;&nbsp;&nbsp;192.168.14.33
&nbsp;&nbsp;}
<span style="color:#f00">&nbsp;&nbsp;track_process {
&nbsp;&nbsp;&nbsp;&nbsp;trkap2
&nbsp;&nbsp;}</span>
&nbsp;&nbsp;authentication {
&nbsp;&nbsp;&nbsp;&nbsp;auth_type PASS
&nbsp;&nbsp;&nbsp;&nbsp;auth_pass [pass1234]
&nbsp;&nbsp;}
&nbsp;&nbsp;virtual_ipaddress {
&nbsp;&nbsp;&nbsp;&nbsp;192.168.14.123/24
&nbsp;&nbsp;}
}
</code>
===== Weight =====
Weight-ul se adauga la priority astfel incat toate nodurile cu Apache2 pornit vor avea urmatoarele prioritati:
* ha01=109
* ha02=107
* ha03=105
In momentul in care Apache2 este oprit pe ha01 priority va scade de la 109 la 99 astfel incat IP-ul va migra pe ha02 care la momentul respectiv va avea o prioritate de 107.

== Alertare Keepalived prin SMTP ==
Keepalived poate trimite alerte pe mail la migrarea unui IP de pe un nod pe altul:

* nano /etc/keepalived/keepalived.conf
===== ha01, ha02 si ha03 =====

<code class="mw-code mw-highlight plainlinks" style="display:block"><!--
--><span style="color:#f00">global_defs {
&nbsp;&nbsp;notification_email {
&nbsp;&nbsp;&nbsp;&nbsp;monitorizare@domeniu.ro
&nbsp;&nbsp;}
&nbsp;&nbsp;notification_email_from keepalived@domeniu.ro
&nbsp;&nbsp;smtp_server mail.domeniu.ro
&nbsp;&nbsp;smtp_connect_timeout 30
}</span>
vrrp_track_process track_apache {
&nbsp;&nbsp;process apache2
&nbsp;&nbsp;weight 10
}
vrrp_instance VIP {
&nbsp;&nbsp;state MASTER
&nbsp;&nbsp;interface ens18
&nbsp;&nbsp;virtual_router_id 66
&nbsp;&nbsp;priority 99
<span style="color:#f00">&nbsp;&nbsp;smtp_alert</span>
&nbsp;&nbsp;advert_int 1
&nbsp;&nbsp;unicast_src_ip 192.168.14.11
&nbsp;&nbsp;unicast_peer {
&nbsp;&nbsp;&nbsp;&nbsp;192.168.14.22
&nbsp;&nbsp;&nbsp;&nbsp;192.168.14.33
&nbsp;&nbsp;}
&nbsp;&nbsp;track_process {
&nbsp;&nbsp;&nbsp;&nbsp;track_apache
&nbsp;&nbsp;}
&nbsp;&nbsp;authentication {
&nbsp;&nbsp;&nbsp;&nbsp;auth_type PASS
&nbsp;&nbsp;&nbsp;&nbsp;auth_pass [pass1234]
&nbsp;&nbsp;}
&nbsp;&nbsp;virtual_ipaddress {
&nbsp;&nbsp;&nbsp;&nbsp;192.168.14.123/24
&nbsp;&nbsp;}
}
</code>
===== Legenda =====
'''notification_email''' = se va trece adresa de mail care va primi alertele de migrare IP<br>
'''notification_email_from''' = se va trece adresa de mail de la care se trimit alertele. Desi keepalived nu face autentificare in serverul de mail, adresa trebuie sa fie una valida<br>
'''smtp_server''' = fqdn-ul serverului de mail<br>
'''smtp_connect_timeout''' = perioada (secunde) ce va trece din momentul din care nodul pierde IP-ul pana va trimite alertarea pe mail

== Recomandari ==
https://www.keepalived.org/