Previewing a configuration

This page describes how to preview a configuration file before creating a deployment. To learn more about configurations, read Configurations Overview.

After you have written a configuration file, you can preview the configuration before you create a deployment. Previewing a configuration lets you see the resources that Deployment Manager would create but does not actually instantiate any actual resources. The Deployment Manager service previews the configuration by:

  1. Expanding the full configuration, including any templates.
  2. Creating a deployment and "shell" resources.

You can preview your configuration by using the preview query parameter when making an insert() request.

Before you begin

Previewing a new configuration

Preview a configuration by using the Google Cloud CLI or by making a direct request to the API.

gcloud

If you're using the Google Cloud CLI, use the create sub-command with the --preview flag:

gcloud deployment-manager deployments create example-config --config configuration-file.yaml \ --preview

The server returns a list of resources whose state is IN_PREVIEW for you to review:

The fingerprint of the deployment is ulPDrJON8E5ySHKC5fcukw== Waiting for create [operation-1492785372594-54dae2ddbff50-58d45d53-12d483cf]...done. Create operation operation-1492785372594-54dae2ddbff50-58d45d53-12d483cf completed successfully. NAME TYPE STATE ERRORS INTENT datadisk-example compute.v1.disk IN_PREVIEW [] CREATE_OR_ACQUIRE vm-example compute.v1.instance IN_PREVIEW [] CREATE_OR_ACQUIRE

API

In the API, use the insert() method with a request body that contains the target and name fields and the preview=true query parameter. Provide your configuration in the target field.

For example, the following API request previews a simple template:

POST https://www.googleapis.com/deploymentmanager/v2/projects/myproject/global/deployments?preview=true {  "name": "example-config",  "target": {  "config": {  "content": "resources:\n- name: vm-created-by-cloud-config\n type: compute.v1.instance\n properties:\n zone: us-central1-a\n machineType: https://www.googleapis.com/compute/v1/projects/myproject/zones/us-central1-a/machineTypes/n1-standard-1\n disks:\n - deviceName: boot\n type: PERSISTENT\n boot: true\n autoDelete: true\n initializeParams:\n diskName: disk-created-by-cloud-config\n sourceImage: https://www.googleapis.com/compute/v1/projects/debian-cloud/global/images/debian-7-wheezy-v20140619\n networkInterfaces:\n networkInterfaces:\n - network: https://www.googleapis.com/compute/v1/projects/myproject/global/networks/default"  }  } }

When a deployment is in preview mode, you can move forward with the deployment in one of three ways:

Performing multiple previews

If you want to change your configuration and perform another preview, use the update command with the --preview flag:

gcloud deployment-manager deployments update example-config \ --config new-config.yaml --preview

In the API, make a PUT() request with an existing deployment and provide the preview=true query parameter. The request body must contain the intent, target, and name fields. For example, the following API request previews a simple update:

PUT https://www.googleapis.com/deploymentmanager/v2/projects/myproject/global/deployments/example-config?preview=true {  "target": {  "config": {  "content": "resources:\n- name: vm-created-by-cloud-config\n type: compute.v1.instance\n properties:\n zone: us-central1-a\n machineType: https://www.googleapis.com/compute/v1/projects/myproject/zones/us-central1-a/machineTypes/n1-standard-1\n disks:\n - deviceName: boot\n type: PERSISTENT\n boot: true\n autoDelete: true\n initializeParams:\n diskName: disk-created-by-cloud-config\n sourceImage: https://www.googleapis.com/compute/v1/projects/debian-cloud/global/images/debian-7-wheezy-v20140619\n networkInterfaces:\n - network: https://www.googleapis.com/compute/v1/projects/myproject/global/networks/default"  }  },  "name": "example-config" }

Deploying or canceling a preview

After previewing a deployment, you can move forward with the deployment by performing an update and committing the configuration. For example, assume you have a deployment named example-config currently in preview mode. You can move forward with the deployment by running the following command:

gcloud deployment-manager deployments update example-config

Deployment Manager uses the last previewed configuration to create a deployment.

Alternatively, if you don't want to move forward with the configuration, you can cancel the preview, and then delete the deployment:

gcloud deployment-manager deployments cancel-preview example-config

While a deployment is in preview mode, you cannot move forward with another configuration. For example, assume you have a deployment called example-config that is in preview mode using a configuration named vm.yaml. You decide that you want to deploy a new configuration named two_vms.yaml to the same deployment, skipping the preview process. While example-config is still in preview mode, you cannot deploy a new configuration. Cancel the preview, and then update the deployment with the new configuration.

What's next