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Hosting-Aware Pruning

This document holds the step-by-step guide to deploy the on-premise deployment variant of a webshop application to showcase the hosting-aware pruning. The webshop application can be deployed in the following deployment variants.

  • on-premise/ local: Kubernetes on a single virtual machine on a local OpenStack (OS) instance
  • cloud: Google Cloud Platform (GCP)


We need to fulfill the following requirements to follow this step-by-step guide.

  • Linux machine, e.g., Ubuntu 22.04
  • Access to an OpenStack instance


First, we install OpenTOSCA Vintner. For more information see Installation.

curl -fsSL | sudo bash -

Next, we install Unfurl.

vintner install unfurl

Next, we configure Unfurl as the orchestrator that should be used for the deployment.

vintner orchestrators init unfurl
vintner orchestrators enable --orchestrator unfurl

Next, we attest that Vintner can use unfurl.

vintner orchestrators attest --orchestrator unfurl

Import the Template

Figure 1: The Variability4TOSCA model.

Next, we import the Variability4TOSCA template.

vintner templates import --template aware --path examples/unfurl-aware

Then, we initialize an application instance.

vintner instances init --instance aware --template aware

We can optionally inspect the Variability4TOSCA model. This model contains all possible elements having conditions assigned. However, due to the hosting-aware pruning, only a handful of condition must be modeled. This is shown in Figure 1.

vintner templates inspect --template aware

Resolve Variability

Figure 2: The derived TOSCA model.

We want to deploy the on-premise variant of the webshop application on Kubernetes using OpenStack. We specify this when resolving variability as follows.

vintner instances resolve --instance aware --presets local

You can optionally inspect the generated TOSCA-compliant model. This template contains only the elements required for the on-premise variant, e.g., Kubernetes. This is shown in Figure 2.

vintner instances inspect --instance aware

Deploy the Application

Finally, we can deploy the application. Therefore, we need to provide deployment inputs, e.g., credentials to OpenStack. These inputs are specified in topology_template.inputs of the TOSCA-compliant model. The following inputs must be defined.

os_compute_network: <OS_COMPUTE_NETWORK>
os_compute_key_name: <OS_COMPUTE_KEY_NAME>
os_compute_ssh_user: <OS_COMPUTE_SSH_USER>
os_compute_ssh_key_file: <OS_COMPUTE_SSH_KEY_FILE>
os_region_name: <OS_REGION_NAME>
os_auth_type: <OS_AUTH_TYPE>
os_auth_url: <OS_AUTH_URL>
os_identity_api_version: <OS_IDENTITY_API_VERSION>
os_interface: <OS_INTERFACE>
os_application_credential_id: <OS_APPLICATION_CREDENTIAL_ID>
os_application_credential_secret: <OS_APPLICATION_CREDENTIAL_SECRET>

# Also required. Just fill them with dummy values.
database_password: <DATABASE_PASSWORD>
gcp_region: <GCP_REGION>
gcp_service_account_file: <GCP_SERVICE_ACCOUNT_FILE>
gcp_project: <GCP_PROJECT>
gcp_auto_scaling: <GCP_AUTO_SCALING>

Next, we start the deployment. The deployment will take around 5-10 minutes.

vintner instances deploy --instance aware --inputs ${INPUTS_PATH}

Do not abort the deployment manually. Not even in case of errors. Once the deployment command exits, the deployment can be retried as follows.

vintner instances continue --instance aware

Test the Application

Next, we can test that the application is correctly working. Therefore, find out the hostname of the provisioned virtual machine.

curl --fail-with-body http://${HOSTNAME_OF_VM}

If no hostname has been assigned, then use the IPv4 address.

curl --fail-with-body http://[${IPv4_ADDRESS_OF_VM}]

This should return the following.

   "MESSAGE": "Successfully executed query",
   "QUERY": "SELECT 1 + 1;",
   "DB_DIALECT": "mysql",
   "DB_NAME": "shop",
   "DB_ADDRESS": "mysql",
   "DB_USERNAME": "root",
   "DB_PASSWORD": "5e88"

We can observe the following.

  • according to MESSAGE, the query has been successful
  • according to DB_ADDRESS, the MySQL instance running in Kubernetes has been used

Thus, we conclude that the application has been deployed as desired.

Undeploy the Application

Afterward, we can undeploy the application.

vintner instances undeploy --instance aware

We can also optionally remove the instance or cleanup the filesystem. Note, cleaning up the filesystem removes any vintner data including, e.g., all imported templates and created instances.

vintner instances delete --instance aware
vintner setup clean --force


This deployment is also executed in our integration pipeline, which is executed once a week. The logs of the corresponding GitHub action can be accessed here. Relevant jobs start with "Unfurl Aware". Note, a GitHub account is required to access these logs. The raw logs are available without requiring an GitHub account.


The assets of this guide can be also found on Zenodo.


This guide is part of our paper published at the CLOSER 2024. Also check our other publications.

Last update: February 29, 2024