Host-Pool Plugin

Cloudify Host-Pool plugin description and configuration

Description

The plugin is an infrastrcture provisioning plugin that is used in conjunction with Cloudify’s Host-Pool Service to use hosts from a pool of existing hosts. When the plugin is requested to provision a host, it will make a request to the Host-Pool-Service, which will in turn look for available matching hosts inside the pool, and assign one to that request.

The same flow is executed when the plugin is requested to release that host. The pool of available hosts will be determined at the time of the Host-Pool-Service installation, as explained below.

Plugin Requirements

• Python Versions:
  • 2.7.x
  • 2.6.x

Host-Pool Plugin

cloudify.hostpool.nodes.Host

Base type for a pool host.

Derived From: cloudify.nodes.Compute

Properties:

• os such as Linux, BSD, Windows, etc.
• filters a dictionary containing a list of tags.

Mapped Operations:

• cloudify.interfaces.worker_installer.install Installs the agent.
• cloudify.interfaces.worker_installer.start Starts the agent.
• cloudify.interfaces.worker_installer.stop Stops the agent.
• cloudify.interfaces.worker_installer.uninstall Uninstalls the agent.

• cloudify.interfaces.worker_installer.restart Restarts agent.

• cloudify.interfaces.lifecycle.create Handles the request of a host allocation in the host pool service.

• cloudify.interfaces.lifecycle.delete Handles the deallocation of a host in the host pool service.

Note that you must provide the service_url of the host pool service as an input to the lifecycle operations.

Attributes:

• ip the private ip of the host.
• user the username of the host.
• port the authentication port of this host.
• public_address the public address of the host.
• password the password of the host.
• key the content of the keyfile used to login to the host.

cloudify.hostpool.nodes.LinuxHost

Derived From: [cloudify.hostpool.nodes.Host]

Properties:

• os linux.

cloudify.hostpool.nodes.WindowsHost

Derived From: [cloudify.hostpool.nodes.Host]

Properties:

• os windows.

Host-Pool Service

The Host-Pool Service is a web service designed for managing a large pool of hosts to be used by cloudify deployments. It allows for the use of multiple existing hosts to be allocated for a deployment. Supports defining hosts by:

• os
• name
• endpoint (IP)
• additional filters

The Host-Pool-Plugin will make calls to this service each time a new host needs to be provisioned/terminated.

To make the installation of this service easy, we have made it available as a regular cloudify node type.

cloudify.nodes.HostPoolService

Derived From: cloudify.nodes.SoftwareComponent

Properties:

• pool relative path to a pool configuration file. This is where you define the hosts you want to “seed” the pool with.
• port the port to run the service on. Defaults to 8080
• debug enable service debug logging
• gunicorn_debug enable gunicorn debug logging
• source the source code of the service. Defaults to latest version.
• working_directory the directory to run the service from inside the host.
• run_as_daemon enable the service to run as a SysV daemon

Mapped Operations:

• cloudify.interfaces.lifecycle.create creates the necessary directories and installs dependencies.
• cloudify.interfaces.lifecycle.configure creates the service configuration file based on information in the properties.
• cloudify.interfaces.lifecycle.start starts the service.
• cloudify.interfaces.lifecycle.stop stops the service.
• cloudify.interfaces.lifecycle.delete deletes the service working directory.

Attributes:

• seed_config the initial configuration of the host pool.
• working_directory the final working directory of the service
• endpoint the url of the service. This URL is determined by combining the port property of the type, with the ip of the host the service is contained within. The ip is either the ip attribute of the containing host node, or, in case it is absent, the ip property of the node. You can effectively think of this endpoint like the cloud endpoints you are probably used to.
• service name defaults to cloudify-hostpool.

Examples

  

tosca_definitions_version: cloudify_dsl_1_2

imports:
  - http://www.getcloudify.org/spec/cloudify/3.3.1/types.yaml
  - https://raw.githubusercontent.com/cloudify-cosmo/cloudify-host-pool-plugin/1.4/plugin.yaml

inputs:
  hostpool_svc_endpoint:
    type: string
    description: |
      Endpoint for the host-pool REST service
    default: http://192.168.1.100:8080

node_templates:
  host_from_pool:
    type: cloudify.hostpool.nodes.LinuxHost
    properties:
      filters:
        tags:
        - redhat
    interfaces:
      cloudify.interfaces.lifecycle:
        create:
          inputs:
            service_url: { get_input: hostpool_svc_endpoint }
        delete:
          inputs:
            service_url: { get_input: hostpool_svc_endpoint }