murano/doc/source/admin/appdev-guide/muranopackages/dynamic_ui.rst

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.. _DynamicUISpec:
Dynamic UI definition specification
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The main purpose of Dynamic UI is to generate application creation
forms "on-the-fly". The Murano dashboard does not know anything about
applications that will be presented in the catalog and which web forms are
required to create an application instance. So all application definitions
should contain an instruction, which tells the dashboard how to create an
application and what validations need to be applied. This document will help
you to compose a valid UI definition for your application.
The UI definition should be a valid YAML file and may contain the following
sections (for version 2.x):
* **Version**
Points out the syntax version in use. *Optional*
* **Templates**
An auxiliary section, used together with an Application section
to help with object model composing. *Optional*
* **Parameters**
An auxiliary section for evaluated once parameters. *Optional*
* **ParametersSource**
A static action name (ClassName.methodName) to call for additional
parameters. *Optional*
* **Application**
Object model description passed to murano engine and used for application
deployment. *Required*
* **Forms**
Web form definitions. *Required*
.. _DynamicUIversion:
Version
-------
The syntax and format of dynamic UI definitions may change over time, so the
concept of *format versions* is introduced. Each UI definition file may contain
a top-level section called *Version* to indicate the minimum version of Murano
Dynamic UI platform which is capable to process it.
If the section is missing, the format version is assumed to be latest supported.
The version consists of two non-negative integer segments, separated by a dot,
i.e. has a form of *MAJOR.MINOR*.
Dynamic UI platforms having the same MAJOR version component are compatible:
i.e. the platform having the higher version may process UI definitions with
lower versions if their MAJOR segments are the same.
For example, Murano Dynamic UI platform of version 2.2 is able to process UI
definitions of versions 2.0, 2.1 and 2.2, but is unable to process 3.0 or
1.9.
Currently, the latest version of Dynamic UI platform is 2.3. It is incompatible
with UI definitions of Version 1.0, which were used in Murano releases before
Juno.
.. note::
Although the ``Version`` field is considered to be optional, its default
value is the latest supported version. So if you intent to use applications
with the previous stable murano version, verify that the version
is set correctly.
Version history
~~~~~~~~~~~~~~~
+---------+-------------------------------------------------------------------+-------------------+
| Version | Changes | OpenStack Version |
+=========+===================================================================+===================+
| 1.0 | - Initial Dynamic UI implementation | Icehouse |
+---------+-------------------------------------------------------------------+-------------------+
| 2.0 | - *instance* field support is dropped | Juno, Kilo |
| | - New *Application* section that describes engine object model | |
| | - New *Templates* section for keeping reusable pieces of Object | |
+---------+-------------------------------------------------------------------+-------------------+
| 2.1 | - New *network* field provides a selection of networks and | Liberty |
| | their subnetworks as a dropdown populated with those which are | |
| | available to the current tenant. | |
+---------+-------------------------------------------------------------------+-------------------+
| 2.2 | - Now *application name* is added automatically to the last | Liberty |
| | service form. It is needed for a user to recognize one | |
| | created application from another in the UI. Previously all | |
| | application definitions contained the *name* property. So to | |
| | support backward compatibility, you need to manually remove | |
| | *name* field from class properties. | |
+---------+-------------------------------------------------------------------+-------------------+
| 2.3 | - Now *password* field supports ``confirmInput`` flag and | Mitaka |
| | validator overloading with single ``regexpValidator`` or | |
| | multiple *validators* attribute. | |
+---------+-------------------------------------------------------------------+-------------------+
| 2.4 | - Parameters and ParametersSource sections were added | Ocata |
| | - ref() YAQL function were added to Application DSL | |
| | - YAQL expressions can be used anywhere in the form definition | |
| | - choice control accepts choices in dictionary format | |
+---------+-------------------------------------------------------------------+-------------------+
Application
-----------
The Application section describes an *application object model*.
The model is a dictionary (document) of application property values (inputs).
Property value might be of any JSON-serializable type (including lists and
maps). In addition the value can be of an object type (another application,
application component, list of components etc.). Object properties are
represented either by the object model of the component (i.e. dictionary) or
by an object ID (string) if the object was already defined elsewhere.
Each object definition (including the one in Application itself) must have a
special ``?`` key called ``object header``. This key holds object metadata most
important of which is the object type name. Thus the Application might look
like this:
.. code-block:: yaml
Application:
?:
type: "com.myCompany.myNamespace.MyClass"
property1: "string property value"
property2: 123
property3:
key1: value1
key2: [1, false, null]
property4:
?:
type: "com.myCompany.myNamespace.MyComponent"
property: value
However in most cases the values in object model should come from input fields
rather than being static as in example above. To achieve this, object model
values can also be of a `YAQL <https://opendev.org/openstack/yaql/src/branch/master/README.rst>`
expression type. With expressions language it becomes possible to retrieve
input control values, do some calculations and data transformations (queries).
Any YAML value that is not enclosed in quote marks and conforms to the YAQL
syntax is considered to be a YAQL expression. There is also an explicit
YAML tag for the YAQL expressions: ``!yaql``.
So with the YAQL addition ``Application`` section might look like this:
.. code-block:: yaml
Application:
?:
type: "com.myCompany.myNamespace.MyClass"
property1: $.formName.controlName
property2: 100 + 20 + 3
property3:
!yaql "'KEY1'.toLower()'": !yaql "value1 + '1'"
key2: [$parameter, not true]
property4: null
When evaluating YAQL expressions ``$`` is set to the forms data (list of
dictionaries with cleaned validated forms' data) and templates and parameters
are available using $templateName ($parameterName) syntax. See below on
templates and parameters.
YAQL comes with hundreds of functions bundled. In addition to that there are
another four functions provided by murano dashboard:
* **generateHostname(pattern, index)** is used for a machine hostname template
generation. It accepts two arguments: name pattern (string) and index
(integer). If '#' symbol is present in name pattern, it will be replaced
with the index provided. If pattern is an empty string, a random name will be
generated.
* **repeat(template, times)** is used to produce a list of data snippets, given
the template snippet (first argument) and number of times it should be
reproduced (second argument). Inside that template snippet current step can
be referenced as *$index*.
* **name()** returns current application name.
* **ref(templateName [, parameterName] [, idOnly])** is used to generate object
definition from the template and then reference it several times in the
object model. This function evaluates template ``templateName`` and
fixes the result in parameters under ``parameterName`` key (or
``templateName`` if the second parameter was omitted). Then it generates
object ID and places it into ``?/id`` field. On the first use of
``parameterName`` or if ``idOnly`` is ``false`` the function will return
the whole object structure. On subsequent calls or if ``idOnly`` is
``true`` it will return the ID that was generated upon the first call.
Templates
---------
It is often that application object model contains number of similar instances
of the same component/class. For example it might be list of servers for
multi-server application or list of nodes or list of components. For such cases
UI definition markup allow to give the repeated object model snippet a name
and then refer to it by the name in the application object model.
Such snippets are placed into ``Templates`` section:
.. code-block:: yaml
Templates:
primaryController:
?:
type: "io.murano.windows.activeDirectory.PrimaryController"
host:
?:
type: "io.murano.windows.Host"
adminPassword: $.appConfiguration.adminPassword
name: generateHostname($.appConfiguration.unitNamingPattern, 1)
flavor: $.instanceConfiguration.flavor
image: $.instanceConfiguration.osImage
secondaryController:
?:
type: "io.murano.windows.activeDirectory.SecondaryController"
host:
?:
type: "io.murano.windows.Host"
adminPassword: $.appConfiguration.adminPassword
name: generateHostname($.appConfiguration.unitNamingPattern, $index + 1)
flavor: $.instanceConfiguration.flavor
image: $.instanceConfiguration.osImage
Then the template can be inserted into application object model or to another
template using ``$templateName`` syntax. It is often case that it is used
together with ``repeat`` function to put several instances of template. In
this case templates may use of ``$index`` variable which will hold current
iteration number:
.. code-block:: yaml
Application:
?:
type: io.murano.windows.activeDirectory.ActiveDirectory
primaryController: $primaryController
secondaryControllers: repeat($secondaryController, $.appConfiguration.dcInstances - 1)
It is important to remember that templates are evaluated upon each access or
``repeat()`` iteration. Thus if the template has some properties set to a
random or generated values they are going to be different for each instance
of the template.
Another use case for templates is when single object is referenced several
times within application object model:
.. code-block:: yaml
Templates:
instance:
?:
type: "io.murano.resources.LinuxMuranoInstance"
image: myImage
flavor: "m1.small"
Application:
?:
type: "com.example.MyApp"
components:
- ?:
type: "com.example.MyComponentType1"
instance: ref(instance)
- ?:
type: "com.example.MyComponentType2"
instance: ref(instance)
In example above there are two components that uses the same server instance.
If this example had ``$instance`` instead of ``ref(instance)`` that would
be two unrelated servers based on the same template i.e. with the same image
and flavor, but not the same VM.
Parameters and ParametersSource
-------------------------------
Parameters are values that are used to parametrize the UI form and/or
application object model. Parameters are put into ``Parameters`` section and
accessed using ``$parameterName`` syntax:
.. code-block:: yaml
Parameters:
param1: "Hello!"
Application:
?:
type: "com.example.MyApp"
stringProperty: $param1
Parameters are very similar to Templates with two differences:
#. Parameter values are evaluated only once per application instance at the
very beginning whereas templates are evaluated on each access.
#. Parameter values can be used to initialize UI control attributes (e.g.
initial text box value, list of choices for a drop down etc.)
However the most powerful feature about parameters is that their values
might be obtained from the application class. Here is how to do it:
#. In one of the classes in the MuranoPL package (usually the main application
class define a static action method without arguments that returns a
dictionary of variables:
.. code-block:: yaml
Name: "com.example.MyApp"
Methods:
myMethod:
Usage: Static
Scope: Public
Body:
# arbitrary MuranoPL code can be used here
Return:
var1: value1
var2: 123
#. In UI definition file add
.. code-block:: yaml
ParametersSource: "com.example.MyApp.myMethod"
The class name may be omitted. In this case the dashboard will try to use
the type of Application object or package FQN for that purpose.
The values returned by the method are going to be merged into Parameters
section like if they were defined statically.
Forms
-----
This section describes markup elements for defining forms, which are currently
rendered and validated with Django. Each form has a name, field definitions
(mandatory), and validator definitions (optionally).
Note that each form is split into 2 parts:
* **input area** - left side, where all the controls are located
* **description area** - right side, where descriptions of the controls are located
Each field should contain:
* **name** - system field name, could be any
* **type** - system field type
Currently supported options for **type** attribute are:
* *string* - text field (no inherent validations) with one-line text input
* *boolean* - boolean field, rendered as a checkbox
* *text* - same as string, but with a multi-line input
* *integer* - integer field with an appropriate validation, one-line text input
* *choice* - drop-down list of variants. Each variant has a display string that
is going to be displayed to the user and associated key that is going to be
a control value
* *password* - text field with validation for strong password, rendered as two
masked text inputs (second one is for password confirmation)
* *clusterip* - specific text field, used for entering cluster IP address
(validation for valid IP address syntax)
* *databaselist* - specific field, a list of databases (comma-separated list of
databases' names, where each name has the following syntax first symbol
should be latin letter or underscore; subsequent symbols can be latin
letter, numeric, underscore, at the sign, number sign or dollar sign),
rendered as one-line text input
* *image* - specific field, used for filtering suitable images by image type
provided in murano metadata in glance properties.
* *flavor* - specific field, used for selection instance flavor from a list
* *keypair* - specific field, used for selecting a keypair from a list
* *azone* - specific field, used for selecting instance availability zone from
a list
* *network* - specific field, used to select a network and subnet from a list
of the ones available to the current user
* *securitygroup* - specific field, used for selecting a custom security group
to assign to the instance
* *volume* - specific field, used for selecting a volume or a volume snapshot
from a list of available volumes (and volume snapshots)
* any other value is considered to be a fully qualified name for some
Application package and is rendered as a pair of controls: one for selecting
already existing Applications of that type in an Environment, second - for
creating a new Application of that type and selecting it
Other arguments (and whether they are required or not) depends on a
field's type and other attributes values. Most of them are standard Django
field attributes. The most common attributes are the following:
* **label** - name, that will be displayed in the form; defaults to **name**
being capitalized.
* **description** - description, that will be displayed in the description area.
Use YAML line folding character ``>-`` to keep the correct formatting during
data transferring.
* **descriptionTitle** - title of the description, defaults to **label**;
displayed in the description area
* **hidden** whether field should be visible or not in the input area.
Note that hidden field's description will still be visible in the
descriptions area (if given). Hidden fields are used storing some data to be
used by other, visible fields.
* **minLength**, **maxLength** (for string fields) and **minValue**,
**maxValue** (for integer fields) are transparently translated into django
validation properties.
* **choices** - a choices for the ``choice`` control type. The format is
``[["key1", "display value1"], ["key2", "display value2"]]``. Starting from
version 2.4 this can also be passed as a
``{key1: "display value1", key2: "display value2"}``
* **regexpValidator** - regular expression to validate user input. Used with
*string* or *password* field.
* **errorMessages** - dictionary with optional 'invalid' and 'required' keys
that set up what message to show to the user in case of errors.
* **validators** is a list of dictionaries, each dictionary should at least
have *expr* key, under that key either some
`YAQL <https://opendev.org/openstack/yaql/src/branch/master/README.rst>`_
expression is stored, either one-element dictionary with *regexpValidator*
key (and some regexp string as value).
Another possible key of a validator dictionary is *message*, and although
it is not required, it is highly desirable to specify it - otherwise, when
validator fails (i.e. regexp doesn't match or YAQL expression evaluates to
false) no message will be shown. Note that field-level validators use YAQL
context different from all other attributes and section: here *$* root object
is set to the value of field being validated (to make expressions shorter).
.. code-block:: yaml
- name: someField
type: string
label: Domain Name
validators:
- expr:
regexpValidator: '(^[^.]+$|^[^.]{1,15}\..*$)'
message: >-
NetBIOS name cannot be shorter than 1 symbol and
longer than 15 symbols.
- expr:
regexpValidator: '(^[^.]+$|^[^.]*\.[^.]{2,63}.*$)'
message: >-
DNS host name cannot be shorter than 2 symbols and
longer than 63 symbols.
helpText: >-
Just letters, numbers and dashes are allowed.
A dot can be used to create subdomains
Using of *regexpValidator* and *validators* attributes with *password*
field was introduced in version 2.3. By default, password should have at
least 7 characters, 1 capital letter, 1 non-capital letter, 1 digit, and 1
special character. If you do not want password validation to be so strong,
you can override it by setting a custom validator or multiple validators for
password. For that add *regexpValidator* or *validators* to the *password*
field and specify custom regexp string as value, just like with any *string*
field.
*Example*
.. code-block:: yaml
- name: password
type: password
label: Password
descriptionTitle: Password
description: >-
Please, provide password for the application. Password should be
5-50 characters long and consist of alphanumeric characters
regexpValidator: '^[a-zA-Z0-9]{5,50}?$'
* **confirmInput** is a flag used only with password field and defaults to
``true``. If you decided to turn off automatic password field cloning, you
should set it to ``false``. In this case password confirmation is not
required from a user.
* **widgetMedia** sets some custom *CSS* and *JavaScript* used for the field's
widget rendering. Note, that files should be placed to Django static folder
in advance. Mostly they are used to do some client-side field
enabling/disabling, hiding/unhiding etc.
* **requirements** is used only with flavor field and prevents user to pick
unstable for a deployment flavor.
It allows to set minimum ram (in MBs), disk space (in GBs) or virtual CPU
quantity.
Example that shows how to hide items smaller than regular *small* flavor
in a flavor select field:
.. code-block:: yaml
- name: flavor
type: flavor
label: Instance flavor
requirements:
min_disk: 20
min_vcpus: 2
min_memory_mb: 2048
* **include_snapshots** is used only with the volume field. ``True`` by default.
If ``True``, the field list includes available volumes and volume snapshots.
If set to ``False``, only available volumes are shown.
* **include_subnets** is used only with network field. ``True`` by default.
If ``True``, the field list includes all the possible combinations of network
and subnet. E.g. if there are two available networks X and Y, and X has two
subnets A and B, while Y has a single subnet C, then the list will include 3
items: (X, A), (X, B), (Y, C). If set to ``False`` only network names will be
listed, without their subnets.
* **filter** is used only with network field. ``None`` by default. If set to a
regexp string, will be used to display only the networks with names matching
the given regexp.
* **murano_networks** is used only with network field. ``None`` by default. May
have values ``None``, ``exclude`` or ``translate``. Defines the handling of
networks which are created by murano.
Such networks usually have very long randomly generated names, and thus look
ugly when displayed in the list. If this value is set to ``exclude`` then these
networks are not shown in the list at all. If set to ``translate`` the
names of such networks are replaced by a string ``Network of %env_name%``.
.. note::
This functionality is based on the simple string matching of the
network name prefix and the names of all the accessible murano
environments. If the environment is renamed after the initial deployment
this feature will not be able to properly translate or exclude its network
name.
* **allow_auto** is used only with network field. ``True`` by default. Defines if
the default value of the dropdown (labeled "Auto") should be present in the
list. The default value is a tuple consisting of two ``None`` values. The logic
on how to treat this value is up to application developer. It is suggested to
use this field to indicate that the instance should join default environment
network. For use-cases where such behavior is not desired, this parameter
should be set to ``False``.
*Network* field and its specific attributes (*include_subnets*, *filter*,
*murano_networks*, *allow_auto*) are available since version 2.1.
Before that, there was no way for the end user to select existing network in
the UI. The only way to change the default networking behavior was the usage
of networking.yaml file. It allows to override the networking setting at
the environment level, for all the murano environments of all the tenants.
Now you can simple add a *network* field to your form definition and provide
the ability to select the desired network for the specific application.
*Example*
.. code-block:: yaml
- instanceConfiguration:
fields:
- name: network
type: network
label: Network
description: Select a network to join. 'Auto' corresponds to a default environment's network.
murano_networks: translate
Besides field-level validators, form-level validators also exist. They
use **standard context** for YAQL evaluation and are required when
there is a need to validate some form's constraint across several
fields.
*Example*
.. code-block:: yaml
Forms:
- appConfiguration:
fields:
- name: dcInstances
type: integer
hidden: true
initial: 1
required: false
maxLength: 15
helpText: Optional field for a machine hostname template
- name: unitNamingPattern
type: string
label: Instance Naming Pattern
required: false
maxLength: 64
regexpValidator: '^[a-zA-Z][-_\w]*$'
errorMessages:
invalid: Just letters, numbers, underscores and hyphens are allowed.
helpText: Just letters, numbers, underscores and hyphens are allowed.
description: >-
Specify a string that will be used in a hostname instance.
Just A-Z, a-z, 0-9, dash, and underline are allowed.
- instanceConfiguration:
fields:
- name: title
type: string
required: false
hidden: true
descriptionTitle: Instance Configuration
description: Specify some instance parameters based on which service will be created.
- name: flavor
type: flavor
label: Instance flavor
description: >-
Select a flavor registered in OpenStack. Consider that service performance
depends on this parameter.
required: false
- name: osImage
type: image
imageType: windows
label: Instance image
description: >-
Select valid image for a service. Image should already be prepared and
registered in glance.
- name: availabilityZone
type: azone
label: Availability zone
description: Select an availability zone, where service will be installed.
required: false
validators:
# if unitNamingPattern is given and dcInstances > 1, then '#' should occur in unitNamingPattern
- expr: $.appConfiguration.dcInstances < 2 or not $.appConfiguration.unitNamingPattern.bool()
or '#' in $.appConfiguration.unitNamingPattern
message: Incrementation symbol "#" is required in the Instance Naming Pattern
Control attributes might be initialized with a YAQL expression. However prior
to version 2.4 it only worked for forms other than the first. It was designed
to initialize controls with values input on the previous step. Starting with
version 2.4 this limitation was removed and it become possible to use
arbitrary YAQL expressions for any of control fields on any forms and use
parameter values as part of these expressions.