Book Image

OpenStack Cloud Computing Cookbook - Fourth Edition

By : Kevin Jackson, Cody Bunch, Egle Sigler, James Denton
Book Image

OpenStack Cloud Computing Cookbook - Fourth Edition

By: Kevin Jackson, Cody Bunch, Egle Sigler, James Denton

Overview of this book

This is the fourth edition of the industry-acclaimed OpenStack Cloud Computing Cookbook, created by four recognized OpenStack experts. It has now been updated to work with the latest OpenStack builds, using tools and processes based on their collective and vast OpenStack experience. OpenStack Open Source Cloud software is one of the most used cloud infrastructures to support a wide variety of use cases, from software development to big data analysis. It is developed by a thriving community of individual developers from around the globe and backed by most of the leading players in the cloud space today. We make it simple to implement, massively scalable, and able to store a large pool of data and networking resources. OpenStack has a strong ecosystem that helps you provision your cloud storage needs. Add OpenStack's enterprise features to reduce the cost of your business. This book will begin by showing you the steps to build up an OpenStack private cloud environment using Ansible. You'll then discover the uses of cloud services such as the identity service, image service, and compute service. You'll dive into Neutron, the OpenStack Networking service, and get your hands dirty with configuring networks, routers, load balancers, and more. You’ll then gather more expert knowledge on OpenStack cloud computing by managing your cloud's security and migration. After that, we delve into OpenStack Object storage and you’ll see how to manage servers and work with objects, cluster, and storage functionalities. Finally, you will learn about OpenStack dashboard, Ansible, Keystone, and other interesting topics.
Table of Contents (15 chapters)
OpenStack Cloud Computing Cookbook Fourth Edition
Contributors
Preface
Another Book You May Enjoy
Index

Rescuing an instance


OpenStack Compute provides a handy troubleshooting tool with rescue mode. Should a user lose an SSH key, or otherwise not be able to boot and access an instance, say, bad iptables settings or failed network configuration, rescue mode will start a minimal instance and attach the disk from the failed instance to aid in recovery. This applies to both Windows and Linux instances as this process essentially allows the mounting of the boot volume of your failed instance as a secondary disk to the rescue instance.

Getting ready

To put an instance into rescue mode, you will need the following information:

  • The openstack command-line client

  • The openrc file containing appropriate credentials

  • The name or ID of the instance

The instance we will use in this example is cookbook.test.

How to do it…

To put an instance into rescue mode, use the following steps:

  1. First, we will put the instance into rescue mode as follows:

    openstack server rescue cookbook.test
    

    This will present us with a temporary...