Category: Linux

Hashicorp Vault , keeping things secret – Part 1 install and configure Vault

Hello folks

Today I am going to talk about a great tool from Hashicorp, it’s called Vault (https://www.vaultproject.io) . This piece of software is in my opinion an essential part it our Devops toolkit. It allows you to safely save, and dynamically generate secrets for your infrastructure. The main use case for me has been to allow me to set passwords in Terraform templates, without exposing the password itself in clear text,  but for now what I am talking about here is how to install it and get it up and running in your Linux Server, and I will also provide a Dockerfile you can use to spin up a container and play around with vault.

So let’s get our hands dirty

1 – Download your binary from https://www.vaultproject.io/downloads.html , you will see links for MacOS, Linux, BSD etc, choose your own . For example

#wget https://releases.hashicorp.com/vault/0.8.1/vault_0.8.1_linux_amd64.zip

2 – Uncompress the archive and copy the file into a directory in $PATH

#unzip vault_0.8.1_linux_amd64.zip ; cp vault /usr/local/bin

3 – Test that tou can execute vault.

#vault -v

this should return something like

#vault -v
Vault v0.8.1 (‘8d76a41854608c547a233f2e6292ae5355154695’)

Of course your values could be different as newer versions are released. You should also do the same thing on your workstation as the same binary is used for the client too. So download it to your computer expand the zip file and copy it to a location of your choice (as long as that location is in $PATH).

So , now we have vault in place and we can start the server, this can be done by using the command

#vault server -config <PATH_TO_CONFIG_FILE>

output will look something like


==> Vault server configuration:

Cgo: disabled
Listener 1: tcp (addr: “0.0.0.0:8200”, cluster address: “0.0.0.0:8201”, tls: “disabled”)
Log Level: info
Mlock: supported: true, enabled: true
Storage: file
Version: Vault v0.8.1
Version Sha: 8d76a41854608c547a233f2e6292ae5355154695

==> Vault server started! Log data will stream in below:

Please make sure your firewall allows port 8200/8201 TCP to this server.

If you want to use Vault inside a docker container you can checkout this git repo , as it contains a Dockerfile and an example configuration file for Vault.

https://github.com/ruimoreira/blogexamples

Ok so now we have vault running. Lets initialize it , I would advise you execute this on your workstation,

export VAULT_ADDR='http://<VAULT_SERVER_IP_ADDRESS>:8200'

Let’s check that we can actually reach it

# vault status
Error checking seal status: Error making API request.

URL: GET http://127.0.0.1:8200/v1/sys/seal-status
Code: 400. Errors:

* server is not yet initialized

so this tells us that we can indeed reach the server, however it’s not initialized.

So let’s do just that.

#vault init


#vault init
Unseal Key 1: IIeMHIGq+xmIDqXN7Q43Lt7nmi5sLvNad5NgUjOVPoiA
Unseal Key 2: phNTpSyjBqobHYeLVOfiaUHQ6iidw2/BowKnTb3HzaC4
Unseal Key 3: jJcuYrSiQRHv0TvD1/AVrHBpd2f6mjtjriGLa66A2O5b
Unseal Key 4: so5WqFp1nmXFeuLE4tUZiglCTEBP2gkc9/teNZNvVOmz
Unseal Key 5: hCNg3wwVfYY/x0A6TLVmvyKyutilr5qvhkiH4mUDHWXR
Initial Root Token: 880fde6a-f672-fe8e-50d0-2e51f566654a

As we can see vault has provided the Unseal Keys, and the Root token to authenticate with.

At this point you need to unseal the vault, and you need to provide 3 keys using vault unseal.

Hope you find this useful and hope to see you again soon.

 

Rui Moreira

PS: If you are using a docker container to play around with Vault, the I would like to remind you to use the -p option to expose the port of the container you are running vault on.

More information here

WordPress Security and Selinux

Hello all,

Here we are again, today I am going to address WordPress, and the security of said platform, and how it could relate to Selinux, and SELinux in general.

Many have claimed that wordpress is in itself a flawed plattform and inherently insecure, I could not disagree more. Of course as with every web application there are a lot of security aspects to be taken into account and this should not be taken lightly. In my opinion there are a few things we could do to increase the security of our wordpress install and our website’s reputation intact or at least not at permanent risk. As most of you know I have in the past worked for one of the most famous hosting companies in the world, the Birthplace of Openstack and overal an awesome place to work at, and during my carreer there I have seen a lot of nonsense around wordpress installs, well the same could be said about several other CMS plattforms but I have to admit that WordPress is one of the most famous, amongst other things I have seen the following errors, but however there are others, these are just the most common :

1 – apache user owning the document root

2 – chmod 777 on the document root

3 – features developed that prevent wordpress or php from being updated

4 – outdated or exploitable plugins

5 – Selinux disabled

Let’s look at each one of them indivudually ,

1 – apache user owning the document root

This is very dangerous and will allow an attacker to exploit possible failures in wordpress to write to the document root of your website, the attacker will then use the file he or she uploads (usually a malicious script) to eventually download some sort of php shell (a piece of software that mimics the functions a shell would implement) and try to take control of your web server and website.

While installing wordpress take into attention the file permissions and the recommendations in the WordPress codex (https://codex.wordpress.org) regarding file permissions. Basically apache needs to be able to write to wp-content/uploads and not much more. If you plan on updating wordpress via the ftp feature, please create a user for that process that user could own the entire document root with apache only to read the files. Also if you are doing this please resctict the ftp process to localhost, as ftp is somewhat insecure.

2 – chmod 777 on the document root

This one is a big no … if your website has chmod 777 in the document root I would suggest that you place it under maintenance and review all the file permissions to what they should be. again the wordpress codex is a good place to start.

3 – features developed that prevent wordpress or php from being updated

This one is my pet peeve, it should never happen your developer should test if his code will still work in the case of a upgrade on wordpress at least. We could argue that if some function gets deprecated in a php version upgrade and that breaks your code, you should in my opinion pay your developer to perform the correct fixes. This might sound like I am parcial to developers, however I do insist that they should not work for free (nobody should really) and if your website’s reputation is important for you then you need to agree with him on  how to proceed. But the wordpress version upgrade should be starting point even before your website goes to production .

4 – outdated or exploitable plugins

This one is really a must, as I have said keeping wordpress and it’s pluggins updated is vital for the security of your website.

5 – Selinux disabled

In my opinion we should never have SELinux disabled, there are always ways to make it work and with the tools we have available (audit2allow, audit2why , etc ) there is no reason why you should have it disabled, instead learn how to use it, embrace it, at least if you are serious about security and about the website you are hosting. If you are not then you have no business hosting a website in the first place .

On my next post I will talk about ways you can improve the performance and perform some basic hardening of your wordpress instance.

Until then … stay safe !

 

Cheers

Rui

 

Centos / Redhat Remove old kernel versions

Hello again

So today I started installing a few updates on one of my servers (centos 7) and had the following issue , I could not install the new kernel version because there was not enough disk space in /boot to accommodate the new kernel , so I went about removing the old files, and solving this problem permanently , so first I installed yum-utils

#yum install yum-utils

Then I used the package-cleanup utility (handy python script , yay python!!! )  that allows us to remove duplicate or orphaned packages.

Here is an example

#package-cleanup –oldkernels –count=2

so what this does is that it removes old kernels and keeps only the last 2 .

So this does what we want , which is to remove the older version of the kernel , however we might have this problem again in the future . Looking for a solution I have checked /etc/yum.conf and there we have the option

installonly_limit=5

according to Red Hat and their deployment guide present here

installonly_limit=value

…where value is an integer representing the maximum number of versions that can be installed simultaneously for any single package listed in the installonlypkgs directive.
The defaults for the installonlypkgs directive include several different kernel packages, so be aware that changing the value of installonly_limit will also affect the maximum number of installed versions of any single kernel package. The default value listed in /etc/yum.conf is installonly_limit=3, and it is not recommended to decrease this value, particularly below 2.

 

So , I changed the yum.conf to read

installonly_limit=2

There , we have avoided this problem.

Of course that this has an impact on how many old versions of the kernel you wish to keep , and I do recommend that you set this value taking into account your needs … but for me at this point I feel that 2 is enough .

 

 

 

 

Linux Academy … learning further and personal development

Hello all

As we all know a part of being a good Sysadmin is learning hot to reinvent yourself every once in a while. This can happen actually quite often as the tech market moves at lightning speed.  So this week I have started using Linux Academy to improve my Linux Mojo and learn a few new tricks  this is proving to be quite interesting as the website not only provides videos with the training materials but also provides you with labs , actual servers where you can test and learn further, I will document my progress as I go but so far it looks grand !!!

Beware that this is not free it costs around 25$/month but it’s in my opinion it’s well worth it if you can get well prepared for your certifications and learn new things .

Another day … another Openssl Bug

Hello there

There has been a lot of noise around a new bug that openssl has reported , but it seems that this is being blown out of proportions (again) it seems that the bug was introduced on a commit from late April 2015 https://git.openssl.org/?p=openssl.git;a=commit;h=6281abc79623419eae6a64768c478272d5d3a426 and the versions if affects have been around for a month. So far the most used distros seem to have not been affected by this issue .

http://people.canonical.com/~ubuntu-security/cve/2015/CVE-2015-1793.html

https://access.redhat.com/solutions/1523323

 

So … nothing to see here … 😀

 

 

 

 

 

Ansible modules development

Hello again

So as a hobby I have started working on an Ansible module to allow adding static routes to several hosts , I got out my recently acquired Python skills and started cracking at it , if you are curious about how to start developing ansible modules here is a good place to start . the module development itself is not hard to get started with , and if you are already familiar with ansible and python ( in fact you don’t need python as you can write modules in any language but I have chosen python  for mine ) if should be fairly straight forward.

I have chosen this module for implement because it seems that it is a common thing to do as a System Administrator and there is no specific module to do this, of course you could just use the command module to add a static route but this module aims to do a bit more than just that, I am thinking about implementing this for the most relevant unix like platforms , namely :

 – Linux

– Red Hat

– Debian

– Ubuntu

– BSD

– Openbsd

– Freebsd

– Solaris

If I can find the time and resources I will try to implement the same for also HPUX and Aix but as I don’t have direct access to those platforms at the moment I cannot promise that I will do so. For now the priority is Linux of course .

The code is available from my github repo but for now it’s just an embryo.

Cheers

 

Rui

RHEL 7 and Systemd

Hello again

So with much anticipation from the community Red Hat has released RHEL 7 , and with it an Enterprise Linux Disto that actually ships Systemd , the replacement for the old style SysV init . I am not saying this is good or bad, traditionally people don’t like change so this is a bit theme right now, in any case here is a Cheat Sheet of the old RHEL 6 equivalents

RHEL 6 RHEL7
chkconfig servicename on systemctl enable servicename
chkconfig servicename off systemctl disable servicename
chkconfig servicename on systemctl enable servicename
chkconfig –list systemctl list-unit-files –type=service
service servicename start systemctl start servicename
service servicename stop systemctl stop servicename

You can also check the more in depth cheat sheet here

One of the things that I found to be a bit strange at the beginning was hostnamectl , that as you might have guesses controlls the hostname , so now changing the hostname for your server is something like

#hostnamectl –static set-hostname myserver.mydomain.com

And yes there is also nmcli and firewallctl but that is another article by itself.

Next: nmcli or How to manage your network on RHEL 7

 

 

 

Newrelic plugins

Hello Internet

Today I was browsing the New Relic webpage searching for what plugins you could install , and I must say I was quite impressed by the vast quantity of supported stuff some of my favorites would be

Memcached

Rackspace Load Balancers

Apache / Nginx of course

Varnish

Redis

Object Rocket Mongo DB

PHP Opcache (nice to have )

For those who don’t know what New Relic is , it’s a software/service  that allows you to monitor the entire stack for your application and collect interesting data back , so you can kill all those nasty bottlenecks, Nice work guys !!!

 

Cheers

 

Dell Latitude E7440 Review

So , the company I work for has assigned me a laptop. The Dell Latitude E7440 which I am reviewing now. One of the requisites for me is that the device is fully compatible with any Linux OS , and this one is. I have loaded it with Fedora 21 and so far it has served me well . Although there are a few issues that have more to do with the laptop itself then the linux distro of choice.

One of the things that sort of disappointed me initially was the keyboard , it bends down when you press the keys in the middle (near the g and h keys) and the whole feel to it is not very nice overall . However the whole laptop is nice, the cpu is more than capable (I7 vpro) capable of good performance even when running a few vms  (which I do ) the model I got has 8GB of ram and a 128G Samsung PM851 SSD , fast and energy efficient as expected.

The camera is very good and the laptop is a very good buy apart from the keyboard issue I have already mentioned.

The Intel® Integrated HD Graphics 4400 works perfectly with Linux and the current version of Gnome (3.14.4) runs very well indeed.

I am still benchmarking the battery life , as I tend to use the device more attached to the docking station (did I mention it has a docking station)  .

More on this matter soon.

To wrap up , the device is a good buy if you are looking for a good Linux laptop, however the keyboard is not very good and Dell should improve this design failure.

You can check the full specs at Dell’s website here

http://www.dell.com/uk/business/p/latitude-e7440-ultrabook/pd