whatenv | teardown clusters of virtual machines

The application requires a password less ssh key pair called:. The application will add the file public key file to the Open Stack user as mykey.
Create a config file with your account details with the name "susecloud.cfg". The auth_url can be set to the 1.1, 2, or 3 api for the cloud.
The steering file is the most important configuration file for whatenv. This defines what virtual machine instances will be created and destroyed as part of a session.
The steering file is a json dictionary, with 4 keys. Each of these 4 keys have a value of a dictionary. These dictionaries have identifiers. These identifiers can have any value and have no significance outside this file and are just surrogate keys to associated the 4 types of metadata presented by whatenv to the open stack cloud. In the above example these identifiers are uuid's but they could equally well be more descriptive such as label_01, image_04, flavor_32, instance_controller.
label
images
flavor
instances
Your test cluster is a made up of a collection of instances, these instances are the VM hosts you want to be created and destroyed on each testing cycle. Each VM may be different from other VM's or similar. These VM's will all need to be destroyed at the end of each testing cycle as well as created in each testing cycle. Within the instances dictionary we have a set of instance dictionaries, each identified by a unique identifier. This will be used to uniquely identify which VM instance in the output state file. One instance corresponds to one VM that will be instantiated. Each instance needs to have a "uuid_image" to defied its operating system image and one "uuid_flavour" to define it's hardware layout. Please see the next sections to explain this in more detail. Although instances can be be identified via the identifier, this causes infelxabilities in interpreting the "state" file and combining and modifying your test clusters. For this reason each instance can have a set of labels. Please see the label section to explain this in more detail.
The open Stack instance you are accessing will have a series of VM images available in the image store so you can run the appropriate Operating system and version of that operating system. Whatenv must be able to select the appropriate image to create VM instance for your use. Within the images dictionary we have a set of images, each identified by a unique identifier. This will be used by instances to specify which image is used to create the instance. Each image is also a JSON dictionary. The value is a dictionary and the value must contain an "OS_IMAGE_NAME" key. as show above. This is used to select the appropriate image, and must match an image name provided by SUSE cloud / Open Stack. Images like flavors and instances can reference a set of labels. These are given the key "usr_label" and presented as a JSON list. labels are optional, but recommended to allow easy use of your cluster.
The open Stack instance you are accessing will have a series of VM flavors available, these define the disks, memory, and number of virtual CPU's. Whatenv must be able to select the appropriate flavor to create VM instances for your use. Within the images dictionary we have a set of images, each identified by a unique identifier. This will be used by instances to specify which image is used to create the instance. Each image is also a JSON dictionary. The value is a dictionary and the value must contain an "OS_FLAVOR_NAME" key. as show above. This is used to select the appropriate flavor, and must match an image name provided by SUSE cloud / Open Stack. Flavor like images and instances can reference a set of labels. These are given the key "usr_label" and presented as a JSON list. labels are optional, but recommended to allow easy use of your cluster.
Labels are a JSON dictionaries. These JOSN dictionaries add metadata to the state file. The final output is a merge of the metadata provided in the steering file and an example is shown:. Labels can be attached to images, flavors or instances. Since instances are composed of images and flavours in open stack, and instances, images and flavours can all have labels, when an instance is created by whatenv all the labales are added toether.
Should labels clash the one label must overide the previous label. Labels are added in the order of presidence:.
Instance
Image
Flavor