When you manage Postfix and have a trouble with your mail infrastructure, you may want to set in maintenance your Postfix without loosing any mails. Here is a way to hold the queue, giving the time to analyze the problem and then release the queue.
I’ve wrote some tips on it. I hope it will help you.
Packer is a tool for creating identical machine images for multiple platforms from a single source configuration. You can win a lot of time by testing your application on multiple environments (AWS, OpenStack, VirtualBox, Vmware…).
Let’s say you’ve got a LAMP environment to deploy in production on OpenStack. However, you can’t perform your development/integration on it as you don’t have access yet. You can’t loose time and wait for it to test.
When you have a huge amount of mail to deliver, you can’t release the queue at once and let the server maximize the outgoing mail throughput ! The result will be: you’ll get blacklisted from a lot of MX servers.
That’s why you should take care of it and do traffic shaping. I’ve wrote a little tips on it.
The 1.5 version of Vagrant has been released and that’s awesome ! They finally did a Cloud where all Vagrant boxes could (https://vagrantcloud.com/) be inventoried and easily deployed through command line !
You can find my boxes here. If you want to add one, it’s really simple:
vagrant box add deimosfr/debian-wheezy And the second awesome feature is…the sharing! You can for example have access to a distant and nated Vagrant instance through SSH!
I recently played with HAProxy and discovered that I’ve never made a documentation regarding this fantastic software. So if you don’t know what HAProxy is, it’s a load balancer working on layer 7 and specialized for http protocol.
It is able to handle sticky sessions which is really powerful. More than that, it has a small footprint and can work under a high load traffic.
Here is my documentation.
It’s been a while now that I’ve heard of Ansible but I only started playing with a week ago. You may certainly know that I’m a Puppet lover, but this solution is more powerful than Puppet in my opinion.
So I started to migrate my personal Puppet to Ansible just to play with. Here are the pros:
No client needed on the clients, only SSH! It’s written in Python By default a lot of modules Not only a configuration management tool, it’s an orchestrator too!
I recently discovered a Vagrant plugin that manage the VirtualBox Guest Additions automatically. I mean, when you launch a virtual machine, it automatically checks if the Guest Additions are installed. If it’s not the case or if they are not up to date, installation of the latest version is made automatically !
Here is how to install it.
