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Scalr 4.5 Install Notes For Cento 6.4

Last year we published an article on installing the open-source version of Scalr:

http://blogs.reliablepenguin.com/2013/08/29/scalr-install-notes

Now there’s a new 4.5 release of Scalr available so it’s time for an update.

We’re installing on Cento 6.4 hosted on a RackSpace Performance 1 Cloud Server.

The installation instructions have improved since the last time around but Scalr is till a complex install:

https://scalr-wiki.atlassian.net/wiki/display/docs/Installing+Scalr+4.5

Follow these instructions one section at a time and make sure you’ve got the section complete and working before moving to the next section. We’ve provided notes below about each section.

Before you start, select a hostname for the server and add a DNS A record. For this article we’ll use:

You’ll have problems later on if you don’t get the hostname setup in advance.

Also I like to add some swap to the server:

 Create UNIX Users and Group for Scalr

I setup a script at /root/env.sh with the environment variable as follows:

This makes it easy to get the environment right.

Notice that we’re using user “apache” instead of “www-data” since this is CentOS instead of Ubuntu.

Configure your firewall

Edit /etc/sysconfig/iptables and add lines shown:

And restart the service:

Install Scalr’s PHP Dependencies

The PHP dependencies are tricky. Tried using the IUS repository but kept having problems with errors like this:

So I started over with the Remi repository:

Now edit /etc/yum.repos.d/remi.repo and enable the “remi” and “remi-php55” repositories.

The instructions say to install the php-pecl-rrd extension now but it’s better to wait due to dependency issues that we’ll see later.

Also notice that we’re installing php-pecl-http1 instead of php-pecl-http. This is critical.

Install Scalr’s Python Dependencies

Python is installed by default so just a couple of additional packages to install:

As with PHP, we’ll defer installing the python-rrdtool package until a later step.

Configure PHP for Scalr

Edit /etc/php.ini and (a) enable “short_open_tags” and (b) set the “date.timezone” setting.

Update System SNMP MIBs

For CentOS there is no “snmp-mibs-downloader”. I ended up doing nothing for this step.

Download and Install Scalr 4.5

I choose to install Scalr in /opt/scalr with the following steps:

Notice that back in the first step, I set the SCALR_INSTALL environment variable. No run the installer:

Install and Configure MySQL

Install MySQL server and set to start on boot:

Set the mysql root login and secure:

http://blogs.reliablepenguin.com/2012/10/09/secure-mysql-installation

I like to add a .my.cnf file:

http://blogs.reliablepenguin.com/2012/10/09/create-my-cnf-file-for-mysql-authentication

Edit the /etc/my.cnf file and add this line to the “[mysqld]” section:

Now create the database and user for Scalr:

And load the database structure and data:

Create the Scalr Cache folder

Install and Configure rrdtool and rrdcached

The default version of rrdtool is too old …. we need at least 1.4:

And now we can get the PHP and Python dependencies that we skipped earlier:

Set rrdcached to start on boot:

Edit /etc/sysconfig/rrdcached and change the “RRDCACHED_USER” to “root” and add the following line:

Now create the graphics and data directories:

And start the service:

Install and Configure Apache

Install Apache “httpd” package and SSL support:

Edit /etc/httpd/conf.d/vhosts.conf and add:

Set Apache to start on boot and start it now:

Configure Scalr

Copy the sample config file:

Now edit the config file at /opt/scalr/app/etc/config.yml and set the following parameters:

Leave the other parameters at default settings.

Configure the Scalr Cronjobs

Edit “apache” cronjobs:

and add the following:

 Configure the Scalr Daemons

Edit /etc/init.d/scalr and copy/paste the following contents:

Now set the service to start on boot and start it for the first time:

Validate your Scalr installation

 Now run the validation script:

Log in to Scalr

Open a browser and go to:

http://scalr.domain.com

Login with user “admin” and password “admin”.

Go to the Admin -> admin -> edit and change the admin password.

All Done!

Scalr install is now complete. You can get started using Scalr by adding a user and building an environment.

 

  • Hey there,

    Thanks a lot for your coverage and helping out the community!

    We (the Scalr team) have recently released an installer for Scalr 4.5 which should be compatible with CentOS 6.4 and RHEL 6.

    Thought you might want to check it out — it’s here: https://github.com/scalr/installer-ng

    Cheers,

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