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Node Templates

---

node_templates represent the actual instances of node types which would eventually represent a running application/service as described in the blueprint.

node_templates are more commonly referred to as nodes. nodes can comprise more than one instance. For example, you could define a node which contains two vms. Each vm will then be called a node_instance.

Declaration

The node_templates section in the DSL is a dictionary where each key is a node template.

  
node_templates:

  node_template_1:
    type: ...
    properties:
      ...
    capabilities:
      scalable:
        properties:
          ...
      ...
    interfaces:
      ...
    relationships:
      ...

  node_template_2:
    ...

  

Schema

Keyname	Required	Type	Description
type	yes	string	The node-type of this node template.
properties	no	dict	The properties of the node template matching its node type properties schema.
instances	no	dict	Instances configuration. (deprecated, replaced by capabilities.scalable)
interfaces	no	interfaces	Used for mapping plugins to interfaces operation or for specifying inputs for already mapped node type operations.
relationships	no	relationships	Used for specifying the relationships this node template has with other node templates.
capabilities	no	dict	Used for specifying the node template capabilities (Supported since: cloudify_dsl_1_3. At the moment only scalable capability is supported)

Example

  
node_types:
  # The following node type is used in the node templates section
  nodes.Nginx:
    derived_from: cloudify.nodes.WebServer
    properties:
      port:
        description: The default listening port for the Nginx server.
        type: integer
    interfaces:
      cloudify.interfaces.lifecycle:
        create:
          implementation: scripts/install-nginx.sh
          inputs:
            process:
              default:
                env:
                  port: 80
        start: scripts/start-nginx.sh

node_templates:
  vm:
    type: cloudify.nodes.Compute
    instances:
      deploy: 2
    properties:
      ip: 192.168.0.11

  nginx:
    # We specify that this node template is of the node type we defined in the node types section
    type: nodes.Nginx
    # properties should match nodes.Nginx type properties schema
    properties:
      port: 80
    interfaces:
      cloudify.interfaces.lifecycle:
        create:
          # inputs should match the inputs schema defined in nodes.Nginx for the create operation
          inputs:
            process:
              env:
                port: { get_property: [SELF, port] }
    relationships:
      - type: cloudify.relationships.contained_in
        target: vm
  

capabilities.scalable Configuration

The capabilities.scalable.properties key is used for configuring the deployment characteristics of the node template.

capabilities.scalable.properties Schema

Keyname	Required	Type	Default	Description
default_instances	no	integer	1	The number of node-instances this node template will have.
min_instances	no	integer	0	The minimum number of allowed node instances. (Not enforced by scale workflow)
max_instances	no	integer	UNBOUNDED	The maximum number of allowed node instances. (Not enforced by scale workflow)

Example:

  
node_templates:
  vm:
    type: cloudify.openstack.nodes.Compute
    capabilities:
      scalable:
        properties:
          default_instances: 5
  

In this example, the vm node would have 5 instances when deployed.

More information about number of instances combined with relationships can be found in the relationships specification.