.. _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 ` 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 `_ 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 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.