Cloud Instance Starter Kit

This project is intended to serve as a starting point for your own Vagrant configuration. It will produce a fully updated VM that you can connect to with vagrant ssh, without any manual intervention; if you are using VirtualBox, the VirtualBox Guest Additions are installed automatically as part of the bootstrap process.

Are the VirtualBox Guest Additions necessary?

The VirtualBox Guest Additions provide a number of useful features, but they are optional (although Vagrant will display a warning if they are missing). The most important features are shared folders, and improved time synchronization. They might also help with clock stability problems on OS X hosts.

If you only need to share files between the host and the guest, please consider using NFS instead of the VirtualBox Guest Additions: it's significantly faster and it doesn't require additional maintenance effort when VirtualBox itself or the guest kernel are updated.

Host requirements

Vagrant and Ansible should be installed on the host. I tested with Vagrant 1.8.1 and Ansible 2.0.1.0 on OS X; while a different host OS shouldn't create any problems, older Vagrant or Ansible versions might.

Supported guest OSes

Only the following images are supported:

• centos/7 (CentOS Linux 7, default)
• centos/6 (CentOS Linux 6)
• projectatomic/adb (Atomic Developer Bundle)

How to use

If you are using another operating system than OS X on the host, please edit the Vagrantfile to provide the correct path to the VBoxGuestAdditions.iso file (this should be part of your VirtualBox installation).

If you are creating a new VM, just run vagrant up. The process takes around 15 minutes on my old host (made in 2009) - it should be much faster on modern hardware. When it's ready, you can connect to the new instance with vagrant ssh.

If you later need to upgrade the guest additions, run vagrant provision; this should only be necessary after a kernel update in the VM, or after upgrading VirtualBox on the host.

Known issues

• If you are getting an error while Ansible is waiting for the host to reboot, increase the delay parameter of the wait_for module in provisioning/roles/base/handlers/main.yml

• The guest will always reboot if it had to apply any updates, before installing the guest additions. This is only necessary if the kernel or some development headers were updated, but since this is not trivial to detect, we will always reboot - just to be sure.

• Vagrant sometimes fails to connect to the guest. This seems to be caused by the guest occasionally not getting a reply from the DHCP server in VirtualBox. After running vagrant up; vagrant destroy -f in a loop over night, I saw this problem in almost 10% of boot attempts. If this happens, you can log in from the console to shut the VM down (VirtualBox 5 allows you to attach to a headless VM).

• VirtualBox 5 provides a KVM paravirtualization interface by default for Linux guests, which causes the guest kernel to set its clocksource to kvm-clock. On some older processors, this causes the system time to significantly fall behind the real time when the CPU is idle (due to the TSC halting when the CPU is idle). Set the paravirtualization interface to none if you encounter this problem.