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Difference between revisions of "Mistral/DSLv2"

Line 3: Line 3:
 
=== Main objects ===
 
=== Main objects ===
  
−
* '''Actions''  
+
* '''Actions'''  
 
* '''Workflows'''  
 
* '''Workflows'''  
−
* '''Tasks''  
+
* '''Tasks'''  
 
* '''Triggers'''
 
* '''Triggers'''
 
* '''Triggers'''
 
* '''Triggers'''
  
−
=== Action ===
+
=== Actions ===
  
 
TODO
 
TODO
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==== YAML example: ====
 
==== YAML example: ====
  
−
TODO
+
'''TODO'''
  
−
=== Workflow ===
+
=== Workflows ===
  
 +
TODO
 
==== Attributes ====
 
==== Attributes ====
  
Line 42: Line 43:
  
 
* '''action''' - name of action to perform
 
* '''action''' - name of action to perform
 +
* '''workflow''' - name of workflow to perform
 
* '''requires''' - list of tasks which should be execute before this tasks, or list of task names as a keys and condition as a value, this is optional parameter
 
* '''requires''' - list of tasks which should be execute before this tasks, or list of task names as a keys and condition as a value, this is optional parameter
 
* '''parameters''' - actual parameters for the task, each value can be either some number, string etc, or YAQL expression to retrieve value from task context
 
* '''parameters''' - actual parameters for the task, each value can be either some number, string etc, or YAQL expression to retrieve value from task context
Line 50: Line 52:
 
===== YAML example: =====  
 
===== YAML example: =====  
  
−
create-vm:
+
'''TODO'''
−
  action: Nova.create-vm
 
−
  parameters:
 
−
    image_id: $.image_id
 
−
    flavor_id: 42
 
−
  requires:
 
−
    task2: '$.value2 = 123'
 
−
    task4: '$.value4 = 122'
 
−
  on-success: task3
 
  
 
=== Triggers ===
 
=== Triggers ===
Line 66: Line 60:
 
==== Attributes ====
 
==== Attributes ====
  
−
* '''type''' - can be PERIODIC, CEILOMETER_ALARM
+
'''TODO'''
−
* '''tasks''' - list of tasks which should be execute on trigger
 
−
* '''parameters''' - list of task parameters
 
  
 
==== YAML example: ====
 
==== YAML example: ====
  
−
triggers:
+
'''TODO'''
−
  backup-vm:
 
−
    type: periodic
 
−
    tasks: [create_backup, delete_old_backup]
 
−
    parameters:
 
−
      cron-pattern: 1 0 * * *
 
  
 
=== Full YAML example: ===
 
=== Full YAML example: ===
  
−
====This example requires the following properties provided in execution context:====
+
'''TODO'''
−
# - nova_url  ## url to Nova service, e.g. http://0.0.0.0:8774/v3
 
−
# - server_name ## Name you want to give to new instance
 
−
# - image_id  ## image id from Glance service
 
−
# - flavor_id ## flavor id - type of instance hardware
 
−
# - ssh_username ## username of your VM
 
−
# - ssh_password ## password to your VM
 
−
# - admin_email ## email address to send notifications to
 
−
# - from_email ## email address to send notifications from
 
−
# - smtp_server ## SMTP server to use for sending emails (e.g. smtp.gmail.com:587)
 
−
# - smtp_password ## password to connect to SMTP server
 
−
 
 
−
 
 
−
Namespaces:
 
−
  Nova:
 
−
    # Nova actions for creating VM, retrieving IP and VM deleting.
 
−
    class: std.http
 
−
    actions:
 
−
      createVM:
 
−
        base-parameters:
 
−
          url: '{$.nova_url}/{$.project_id}/servers'
 
−
          method: POST
 
−
          headers:
 
−
            X-Auth-Token: $.auth_token
 
−
            Content-Type: application/json
 
−
          body:
 
−
            server:
 
−
              name: $.server_name
 
−
              imageRef: $.image_id
 
−
              flavorRef: $.flavor_id
 
−
        output:
 
−
          vm_id: $.content.server.id
 
−
 
 
−
      getIP:
 
−
        base-parameters:
 
−
          url: '{$.nova_url}/{$.project_id}/servers/{$.vm_id}'
 
−
          method: GET
 
−
          headers:
 
−
            X-Auth-Token: $.auth_token
 
−
        output:
 
−
          vm_ip: "$.content.server.addresses.novanetwork.where($.'OS-EXT-IPS:type' = 'floating')[0].addr"
 
−
 
 
−
      deleteVM:
 
−
        base-parameters:
 
−
          url: '{$.nova_url}/{$.project_id}/servers/{$.vm_id}'
 
−
          method: DELETE
 
−
          headers:
 
−
            X-Auth-Token: $.auth_token
 
−
        output:
 
−
          status: $.status
 
−
 
 
−
  Server:
 
−
    actions:
 
−
      # HTTP request to the server.
 
−
      calcSumm:
 
−
        class: std.http
 
−
        base-parameters:
 
−
          url: 'http://{$.vm_ip}:5000/summ'
 
−
          method: POST
 
−
          body:
 
−
            arguments: $.arguments
 
−
        output:
 
−
          summ_result: $.content.result
 
−
 
 
−
  Ssh:
 
−
    class: std.ssh
 
−
    base-parameters:
 
−
      host: $.vm_ip
 
−
      username: $.username
 
−
      password: $.password
 
−
    actions:
 
−
      # Simple SSH command.
 
−
      waitSSH:
 
−
        base-parameters:
 
−
          cmd: 'ls -l'
 
−
 
 
−
      # SSH command to run the server.
 
−
      runServer:
 
−
        base-parameters:
 
−
          cmd: 'nohup python ~/web_app.py > web_app.log &'
 
−
 
 
−
Workflow:
 
−
  tasks:
 
−
    # Create a VM (request to Nova).
 
−
    createVM:
 
−
      action: Nova.createVM
 
−
      parameters:
 
−
        server_name: $.server_name
 
−
        image_id: $.image_id
 
−
        flavor_id: $.flavor_id
 
−
        nova_url: $.nova_url
 
−
        project_id: $.project_id
 
−
        auth_token: $.auth_token
 
−
      publish:
 
−
        vm_id: vm_id
 
−
      on-success: waitForIP
 
−
      on-error: sendCreateVMError
 
−
 
 
−
    # Wait till the VM is assigned with IP address (request to Nova).
 
−
    waitForIP:
 
−
      action: Nova.getIP
 
−
      retry:
 
−
        count: 10
 
−
        delay: 10
 
−
      publish:
 
−
        vm_ip: vm_ip
 
−
      parameters:
 
−
        nova_url: $.nova_url
 
−
        project_id: $.project_id
 
−
        auth_token: $.auth_token
 
−
        vm_id: $.vm_id
 
−
      on-success: waitSSH
 
−
      on-error: sendCreateVMError
 
−
 
 
−
    # Wait till operating system on the VM is up (SSH command).
 
−
    waitSSH:
 
−
      action: Ssh.waitSSH
 
−
      retry:
 
−
        count: 10
 
−
        delay: 10
 
−
      parameters:
 
−
        username: $.ssh_username
 
−
        password: $.ssh_password
 
−
        vm_ip: $.vm_ip
 
−
      on-success: runServer
 
−
      on-error: sendCreateVMError
 
−
 
 
−
    # When SSH is up, we are able to run the server on VM (SSH command).
 
−
    runServer:
 
−
      action: Ssh.runServer
 
−
      parameters:
 
−
        vm_ip: $.vm_ip
 
−
        username: $.ssh_username
 
−
        password: $.ssh_password
 
−
      on-success: calcSumm
 
−
      on-error: sendCreateVMError
 
−
 
 
−
    # Send HTTP request on server and calc the result.
 
−
    calcSumm:
 
−
      action: Server.calcSumm
 
−
      retry:
 
−
        count: 10
 
−
        delay: 1
 
−
      parameters:
 
−
        arguments:
 
−
          - 32
 
−
          - 45
 
−
          - 23
 
−
        vm_ip: $.vm_ip
 
−
      publish:
 
−
        result: summ_result
 
−
      on-finish: sendResultEmail
 
−
 
 
−
    # In case of createVM error send e-mail with error message.
 
−
    sendResultEmail:
 
−
      action: std.email
 
−
      parameters:
 
−
        params:
 
−
          to: [$.admin_email]
 
−
          subject: Workflow result
 
−
          body: |
 
−
            Workflow result of execution {$.__execution.id} is {$.result}
 
−
 
 
−
            -- Thanks, Mistral Team.
 
−
        settings:
 
−
          smtp_server: $.smtp_server
 
−
          from: $.from_email
 
−
          password: $.smtp_password
 
−
      on-finish: deleteVM
 
−
 
 
−
    # In case of createVM error send e-mail with error message.
 
−
    sendCreateVMError:
 
−
      action: std.email
 
−
      parameters:
 
−
        params:
 
−
          to: [$.admin_email]
 
−
          subject: Workflow error
 
−
          body: |
 
−
            Failed to create a VM in execution {$.__execution.id}
 
−
 
 
−
            -- Thanks, Mistral Team.
 
−
        settings:
 
−
          smtp_server: $.smtp_server
 
−
          from: $.from_email
 
−
          password: $.smtp_password
 
−
      on-finish: deleteVM
 
−
 
 
−
    # Destroy the VM (request to Nova).
 
−
    deleteVM:
 
−
      action: Nova.deleteVM
 
−
      parameters:
 
−
        nova_url: $.nova_url
 
−
        project_id: $.project_id
 
−
        auth_token: $.auth_token
 
−
        vm_id: $.vm_id
 
−
 
 
−
==== Initial execution context ====
 
−
  {
 
−
    "nova_url": <nova_url>,
 
−
    "image_id": <image_id>,
 
−
    "flavor_id": <flavor_id>,
 
−
    "server_name": <server_name>,
 
−
    "ssh_username": <ssh_username>,
 
−
    "ssh_password": <ssh_password>,
 
−
    "admin_email": <admin_email>,
 
−
    "from_email": <from_email>,
 
−
    "smtp_server": <smtp_server>,
 
−
    "smtp_password": <smtp_password>,
 
−
  }
 
−
 
 
−
'''When a workflow starts Mistral also adds execution information into the context so the context looks like the following:'''
 
−
 
 
−
  {
 
−
    "nova_url": TBD,
 
−
    "image_id": TBD,
 
−
    "image_id": <image_id>,
 
−
    "flavor_id": <flavor_id>,
 
−
    "server_name": <server_name>,
 
−
    "ssh_username": <ssh_username>,
 
−
    "ssh_password": <ssh_password>,
 
−
    "admin_email": <admin_email>,
 
−
    "from_email": <from_email>,
 
−
    "smtp_server": <smtp_server>,
 
−
    "smtp_password": <smtp_password>,
 
−
    "__execution": {
 
−
      "id": "234234",
 
−
      "workbook_name" : "my_workbook",
 
−
      "project_id": "ghfgsdfasdfasdf"
 
−
      "auth_token": "sdfljsdfsdf-234234234",
 
−
      "trust_id": "oiretoilkjsdfglkjsdfglkjsdfg"
 
−
    }
 
−
  }
 

Revision as of 20:12, 23 September 2014

Mistral DSL version 2 specification

Main objects

  • Actions
  • Workflows
  • Tasks
  • Triggers
  • Triggers

Actions

TODO

Attributes

  • name - action name (string without space, mandatory attribute).
  • base - name of base action that this action is built on top of.
  • base-input - dictionary whose structure is defined by action class. For example, for 'std.http' action it contains 'url', 'method', 'body' and 'headers' according to HTTP protocol specification.
  • input - list containing parameter names which should or could be specified in task. This attribute is optional and used only for documenting purposes.
  • output - any data structure defining how to transform the output of base action into the output of this action. I can optionally have YAQL expressions to access properties of base action output. (See more about YAQL at https://pypi.python.org/pypi/yaql/0.3)

YAML example:

TODO

Workflows

TODO

Attributes

  • tasks - list of tasks in this workflow, each task represents a computational step in the workflow.

YAML example:

TODO

Task

Represents a step in workflow, for example 'TODO'

Attributes

  • action - name of action to perform
  • workflow - name of workflow to perform
  • requires - list of tasks which should be execute before this tasks, or list of task names as a keys and condition as a value, this is optional parameter
  • parameters - actual parameters for the task, each value can be either some number, string etc, or YAQL expression to retrieve value from task context
  • on-success - task which will be scheduled on execution after current task has finished with state 'SUCCESS'
  • on-error - task which will be scheduled on execution after current task has finished with state 'ERROR'
  • on-finish - task which will be scheduled on execution after current task has finished
YAML example:

TODO

Triggers

Using triggers it is possible to run workflows according to specific rules: periodically setting a cron (http://en.wikipedia.org/wiki/Cron) pattern or on external events like ceilometer alarm.

Attributes

TODO

YAML example:

TODO

Full YAML example:

TODO

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