deb-murano/doc/source/articles/app_pkg.rst

Composing application package manual

Murano is Application catalog that supports types of applications. This document intends to make composing application packages easily.

Step 1. Prepare Execution Plans

An Execution Plan is a set of metadata that describes the installation process of an application in a virtual machine. It's a minimal unit of execution that can be triggered in Murano Workflows and should be understandable by Murano agent. From Execution plans any script can be triggered. It could be any type of scripts which will execute commands and install application components as the result. Each script may consist of one or more files. Scripts may be reused across several Execution Plans. One of the scripts should be an entry point and should be specified in a resource template file in Scripts. Besides the Scripts section the following sections must be presented in a resource template file:

• FormatVersion - version of Execution Plan syntax format

• Version - version of Execution Plan

• Name - human-readable name of the Execution Plan

• Parameters - parameters received from MuranoPL

• Body - Python statement, should start with | symbol

• Scripts - dictionary that maps script names to script definitions.

  Scripts are the building blocks of Execution Plans and they may be executed as a whole (like a single piece of code), expose some functions that can be independently called in scripts. This depends on Deployment Platform and Executor capabilities. One script can be defined with the following properties

  • Type Deployment Platform name that script is targeted to.
  • Version optional minimum version of deployment platform/executor required by the script.
  • EntryPoint relative path to the file that contains a script entry point
  • Files This is an optional array of additional files required for the script. Use <> to specify a relative path to the file. The root directory is Resource/scripts.
  • Options an optional argument of type contains additional options

Example DeployTelnet.template

FormatVersion: 2.0.0
Version: 1.0.0
Name: Deploy Telnet

Parameters:
  appName: $appName

Body: |
  return deploy(args.appName).stdout

Scripts:
  deploy:
    Type: Application
    Version: 1.0.0
    EntryPoint: deployTelnet.sh
    Files:
      - installer.sh
      - common.sh
    Options:
      captureStdout: true
      captureStderr: false

Step 2. Prepare MuranoPL class definitions

MuranoPL classes control application deployment workflow execution. Full information about MuranoPL classes see here: MuranoPL Spec

Example telnet.yaml

Namespaces:
  =: io.murano.apps.linux
  std: io.murano
  res: io.murano.resources


Name: Telnet

Extends: std:Application

Properties:
  name:
    Contract: $.string().notNull()

  instance:
    Contract: $.class(res:Instance).notNull()


Workflow:
  deploy:
    Body:
      - $this.find(std:Environment).reporter.report($this, 'Creating VM for Telnet instace.')
      - $.instance.deploy()
      - $this.find(std:Environment).reporter.report($this, 'Instance is created. Setup Telnet service.')
      - $resources: new('io.murano.system.Resources')
      # Deploy Telnet
      - $template: $resources.yaml('DeployTelnet.template')
      - $.instance.agent.call($template, $resources)
      - $this.find(std:Environment).reporter.report($this, 'Telnet service setup is done.')

Note, that

• io.murano.system.Resources is a system class, defined in MuranoPL. More information about MuranoPL system classes is available here: class_definitions.
• io.murano.resources.Instance is a class, defined in the core Murano library, which is available here. This library <core_library> contains Murano Agent templates and virtual machine initialization scripts.
• $this.find(std:Environment).reporter.report($this, 'Creating VM for Telnet instance.') - this is the way of sending reports to Murano dashboard during deployment

Step 3. Prepare dynamic UI form definition

Create a form definition in a yaml format. Before configuring a form, compose a list of parameters that will be required to set by a user. Some form fields that are responsible for choosing a flavor, image and availability zone are better to use in every application creation wizard. Syntax of Dynamic UI can be found see at the corresponding section: Dynamic UI Definition specification <DynamicUISpec>. Full example with Telnet application form definition Telnet Definition <TelnetUI>.

Step 4. Prepare application logo

Find or create a simple image (in a .png format) associated with your application. Is should be small and have a square shape. You can specify any name of your image. In our example, let's name it telnet.png.

Step 5. Prepare manifest file

General application metadata should be described in the application manifest file. It should be in a yaml format and should have the following sections

• Format - version of a manifest syntax format
• Type - package type. Valid choices are Library and Application
• Name - human-readable application name
• Description - a brief description of an application
• Author - person or company name which created an application package
• Classes - MuranoPL class list, on which application deployment is based
• Tags - list of words, associated with this application. Will be helpful during the search. Optional parameter

Example manifest.yaml

Format: 1.0
Type: Application
FullName: io.murano.apps.linux.Telnet
Name: Telnet
Description: |
 Telnet is the traditional protocol for making remote console connections over TCP.
Author: 'Mirantis, Inc'
Tags: [Linux, connection]
Classes:
 io.murano.apps.linux.Telnet: telnet.yaml
UI: telnet.yaml
Logo: telnet.png

Step 6. Compose a zip archive

An application archive should have the following structure

• Classes folder

  MuranoPL class definitions should be put inside this folder

• Resources folder

  This folder should contain Execution scripts

  * Scripts folder

  All script files, needed for an application deployment should be placed here

• UI folder

  Place dynamic ui yaml definitions here or skip to use the default name ui.yaml

• logo.png

  Image file should be placed in the root folder. It can have any name, just specify it in the manifest file or skip to use default logo.png name

• manifest.yaml

  Application manifest file. It's an application entry point. The file name is fixed.

Congratulations! Your application is ready to be uploaded to an Application Catalog.