How to get Virtualbox VMs to talk to each other

I'm busy writing an Ansible script and want to test it locally before trying to deploy it anywhere. The easiest way to try and make my local environment as close to my deployment environment was to set up a network of Virtualbox VMs.

The problem was that I've always configured my VM's to use NAT networking. I ssh onto them by setting port forwarding and have never really needed them to have their own address.

The solution to this problem is pretty simple. Just stop the machines and add a new network adapter of type "Host Only". This adapter will handle communication between the guest and host machines.

The trick is that you need to configure the guest OS network interface too.

To do this SSH onto your VM and run "ip add" to list your network adapters. If you're like me and started with NAT before adding "Host Only" as your second adapter the output should look something like this:

You need to identify the adapter that is your "Host Only" network. You can do this by running "ip add" on your host machine and looking for the vboxnet0 network address (assuming you're using the defaults given to you by Virtualbox).

Now you need to edit /etc/network/interfaces and tell Linux (I'm using Ubuntu 16.04) to set up that interface. Add lines like this snippet to your file:

Now your virtual machines will have an ip address (you can grab it with ifconfig) that you can set up in your Ansible inventory.

Comments

Separating business logic from persistence layer in Laravel

There are several reasons to separate business logic from your persistence layer. Perhaps the biggest advantage is that the parts of your application which are unique are not coupled to how data are persisted. This makes the code easier to port and maintain. I'm going to use Doctrine to replace the Eloquent ORM in Laravel. A thorough comparison of the patterns is available here . By using Doctrine I am also hoping to mitigate the risk of a major version upgrade on the underlying framework. It can be expected for the ORM to change between major versions of a framework and upgrading to a new release can be quite costly. Another advantage to this approach is to limit the access that objects have to the database. Unless a developer is aware of the business rules in place on an Eloquent model there is a chance they will mistakenly ignore them by calling the ActiveRecord save method directly. I'm not implementing the repository pattern in all its ...

Using Azure Active directory as an OAuth2 provider for Django

Azure Active Directory is a great product and is invaluable in the enterprise space. In this article we'll be setting it up to provide tokens for the OAuth2 client credentials grant. This authorization flow is useful when you want to authorize server-to-server communication that might not be on behalf of a user. This diagram, by Microsoft, shows the client credentials grant flow. From Microsoft documentation The flow goes like this: The client sends a request to Azure AD for a token Azure AD verifies the attached authentication information and issues an access token The client calls the API with the access token. The API server is able to verify the validity of the token and therefore the identity of the client. The API responds to the client Setting up Azure AD as an OAuth2 identity provider The first step is to create applications in your AD for both your API server and the client. You can find step-by-step instructions on how to register the applications o...

"Word of the Day" PHP script (with word list)

I was looking around for a way to generate a word of the day on the web and didn't find anything. So I coded a quick and dirty script to do it. Just in case anybody does a Google search and manages to find my blog: here is my Word of the Day PHP script : Copy this code snippet into a wordoftheday.php file: $file = fopen("interesting_words.txt","r"); $raw_string = fread($file,filesize("interesting_words.txt")); fclose($file); $words_array = explode("|",$raw_string); echo $words_array[array_rand($words_array)]; Of course the real issue I had was finding a list of interesting words in the right format. Here is the list of interesting words that I used: Copy this into a file called interesting_words.txt : ubiquitous : being or seeming to be everywhere at the same time; omnipresent| ecdysiast : a striptease artist| eleemosynary : of, relating to, or dependent on charity| gregious : c...

Adventures in IT

Search This Blog