Cloud-init: The great forgotten

A little time ago (more than 1 year ago) I began investigating cloud-init. I saw some redhat paper talking about cloud-init and it seemed to be really powerful simplifying massive vm deployments.
Someone close to me told me that: “don’t lose your time, we’ll use terraform/docker/k8s/whatever

But the inception was already done, I read the documentation and started testing the technology.

What I’ve seen is that cloud-init is everywhere: I think that all linux “cloud” vm’s are using it. It’s really sturdily and simple, it does what it is supposed to do… That is part of its greatness and of its weakness.

The good part is well known: cloud-init service starts when the vm starts and does what you tell it to do through a YAML script: Installs software, create users, perform basic configs…
Its weakness is that cloud-init is a very simple software designed for the cloud, if your cloud architecture is not standard, you will have to make some tricks to bypass them.

For example, I was not using dhcp for VM’s networking and booting a VM with cloud-init without dhcp is really tricky… You can see a YAML script for static network here:

All that has given me a background and a global vision to understand the inner technology used on “cloud” platform (any cloud platform)… it seems that time has proved me right :-)

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Problems after upgrade mariadb

As you should know, there’s an important bug on TLS libs on every linux OS.
So upgrade is mandatory.
There’s also another little update in mariadb if you’re using it instead of mysql.
The problem is there, but not the indicator.

The problem in my case comes from the smtp server, I got the error:

535 5.7.8 Error: authentication failed: authentication failure

While tring to send an email (only sending, receiving works fine).
Looking in mail.log:

Mar  6 10:49:06 ciberterminal postfix/smtpd[29949]: warning: SASL authentication failure: Password verification failed
Mar  6 10:49:06 ciberterminal postfix/smtpd[29949]: warning: localhost.localdomain[127.0.0.1]: SASL authentication failed: authentication failure

Auth failed from SASL? WTF!
So i began debuging it:

/usr/sbin/saslauthd -a pam -c -m /var/spool/postfix/saslauthd -r -n 1 -d -VVVVVVVVVV

But it only shows:

do_auth: auth failure: [user=dodger@ciberterminal.net] [service=smtp] [realm=ciberterminal.net] [mech=pam] [reason=PAM auth error]

Anything else.
Searching internet, I saw that post, I forgot to look for errors on auth.log!
Here it is:

Mar  7 10:48:41 ciberterminal saslauthd[4552]: PAM unable to dlopen(pam_mysql.so): /lib/security/pam_mysql.so: symbol make_scrambled_password, version libmysqlclient_18 not defined in file libmysqlclient.so.18 with link time reference
Mar  7 10:48:41 ciberterminal saslauthd[4552]: PAM adding faulty module: pam_mysql.so
Mar  7 10:48:41 ciberterminal saslauthd[4552]: DEBUG: auth_pam: pam_authenticate failed: Module is unknown
Mar  7 10:48:41 ciberterminal saslauthd[4552]: do_auth         : auth failure: [user=trian@ciberterminal.net] [service=smtp] [realm=ciberterminal.net] [mech=pam] [reason=PAM auth error]

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Script to check Oracle remotely (nagios or whatever)

For all of you that are not the lucky owner of an Enterprise Manager license or you simply want to use nagios or another monitoring engine to get status and graphs of oracle, probably you’ll be using the “check_remote_oracle” plugin.

If you’re a scripter/developer maybe you’ll understand me when you open an script and see an COMPLETELY UNREADABLE code, with no functions, no indentation… etc
And then you’ll have to change anything stupid inside the script and then f**k it does not work!

This is the story of that script, I installed it, then I have to do some changes… and then I decided to rewrite it completely…
I’m not the best scripter of the world, but I know how to use functions, indentation and that useless shit :-P

You can read the whole documentation on its wiki page.

Enjoy!

PS: updated the instructions, I forgot the information about the unprivileged user for connecting to Oracle instance.
PS2: Updated again, new control!

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Openvpn in the TP-LINK WR841N[D]

Hi folks,
Here comes a post to improve that great router from TP-LINK.
Of course, I suppose you’re running openwrt on it to use the whole power of it.
The 1st I saw was that you have available a plenty set of packages… but you don’t have enough ROM to install them :-P
Inspecting a bit, I saw that under /tmp you have a “lot” of free space! (about 14MB), that will be enough to allow run openvpn without problems.
The main problem? Its a ramdisk, so each boot, everything there disappears.
What I’ve done? Install the basics with opkg and wget on boot the rest ;-)

UPDATED SCRIPT!

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Rendimiento de algunas versiones de Android

Como usuario freak de android, de vez en cuando me gusta ir cambiando de rom para ver qué se ofrece de nuevo :-)
Asi que soy asiduo de XDA…

Esta semana me decidí a cambiar mi cyanogenmod 10.0 por “alguna otra” y decidí probar la “Slim beam” por aquello de “slim”, a ver si realmente es slim y tal.

La verdad es que es la 2ª vez que me meto el batacazo con una rom, la otra fue también con una 4.2.2 (y volví a 4.1.2).
Pero es que esto es exagerado, yo creo que ni la stock rom iba TAN MAL, es arrancar Opera con más de 1 pestaña (o 1 pestaña con muchas cosas) y se queda congelado.

No sé si es que no le he hecho el tunning apropiado (overclock, vaya), por que menos apps no puedo tener! ya me cuido de tener pocas cosas corriendo.
En fin, que voy a probar una AOKP pura y sino, otra vez a CM…

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UPS Salicru en Nut

Después de ver la exigua entrada del compañero “cerebro” en su blog y viendo que yo estoy en la misma situación que algunas personas, he dedicido publicar un mini-howto para los SAIS Salicru con NUT (sin cacti :-P)

Lo primero por supuesto es bajar el código fuente (en mi caso obligatorio, seguramente en una distribución normal, no haga falta ;-) ).

En mi caso, lo he configurado con esta linea:
./configure --prefix=/home/apps/nut \
--with-usb \
--without-doc \
--with-serial \
--without-ipmi \
--without-freeipmi \
--without-macosx_ups \
--without-avahi \
--with-cgi

Y compilado como siempre :-P

La configuración tal como dice el blog anterior se basa en el driver “blazer_usb”.
Como no tengo mucho tiempo, en vez de leer el manual fui por la via rápida (prueba-> error o ingeniería inversa) y me ha costado un poco descifrar como va el tema.
La cuestión es que hay que lanzar 3 demonios:

  • upsdrvctl lanza el “driver” encargado de coumincarse con el UPS
  • upsd se comunica con el driver (blazer_usb) y abre un socket
  • upsmon se conecta al socket de upsd y monitoriza

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