| NETMOD Working Group | S. Mansfield, Ed. |
| Internet-Draft | Ericsson Inc. |
| Intended status: Informational | B. Zeuner |
| Expires: September 19, 2016 | Deutsche Telekom AG |
| N. Davis | |
| Ciena | |
| Y. Yun | |
| Fiberhome | |
| Y. Tochio | |
| Fujitsu | |
| K. Lam | |
| E. Varma | |
| Alcatel Lucent | |
| March 18, 2016 |
Guidelines for Translation of UML Information Model to YANG Data Model
draft-mansfield-netmod-uml-to-yang-02
This document defines guidelines for translation of data modeled with UML to YANG including mapping of object classes, attributes, data types, associations, interfaces, operations and operation parameters, notifications, and lifecycle.
This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.
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Copyright (c) 2016 IETF Trust and the persons identified as the document authors. All rights reserved.
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As discussed in draft-lam-teas-usage-info-model-net-topology [I-D.lam-teas-usage-info-model-net-topology] a Data Model (DM) may be derived from an Information Model (IM). However, in order to assure a consistent and valid data modelling language representation that enables maximum interoperability, translation guidelines are required. A set of translation rules also assists in development of automated tooling.
This draft defines guidelines for translation of data modelled with UML [OMG-UML-2.4] (as constrained by the ONF's UML Modeling Guidelines [ONF-TR-514]) to YANG (defined in RFC6020 [RFC6020] and YANG Update [I-D.ietf-netmod-rfc6020bis]) including mapping of object classes, attributes, data types, associations, interfaces, operations and operation parameters, notifications, and lifecycle.
The following terms are defined in RFC6020 [RFC6020]
The following terms are defined in UML 2.4 [OMG-UML-2.4]
This document defines translation rules for all constructs used in a UML based IM to a data model using YANG.
While some mapping rules are straightforward, an IM in UML uses some constructs that cannot be mapped directly to a DM using YANG and conventions are described to make the translation predictable. Additionally, in some cases multiple mapping approaches are possible and selection among these is also necessary to assure interoperability.
Mapping guidelines for these constructs are provided in the following sections.
Where "??" is inserted in the table, it means that the specific mapping is for further study as it is either as yet unclear how to map the construct or that there are multiple ways of doing the mapping and a single one needs to be selected.
A table will be included summarizing constructs in UML that do not directly map to YANG and where in this draft the associated guidelines for mapping these constructs will be provided.
+-------------------------------------------------------------------+
| Object Class |
| - Real object classes having/inheriting at least one attribute |
| identified as "identifier" will be mapped to a "list" statement |
| - Real object classes not having/inheriting any attribute |
| identified as "identifier" will be mapped to a "container" |
| statement |
| - Abstract object classes used for inheritance will be mapped |
| to a "grouping" statement |
+-------------------------------------------------------------------+
| UML Artifact | YANG Artifact | Comment |
+-------------------------------------------------------------------+
| documentation | "description" | Multiple "applied |
| "Applied comments" | substatement | comments" defined |
| (carried in XMI as | | in UML, need to be|
| "ownedComment") | | collapsed into a |
| | | single |
| | | "description" |
| | | substatement. |
+-------------------------------------------------------------------+
| superclass(es) | "grouping" statement | Concrete |
| | | superclasses are |
| | | then mapped to |
| | | container/list |
| | | which uses these |
| | | groupings. |
+-------------------------------------------------------------------+
| abstract | "grouping" statement | It is possible |
| | | that the |
| | | superclass or |
| | | abstract class |
| | | contains the key |
| | | attribute for the |
| | | instantiated |
| | | subclass, this |
| | | requires the |
| | | creation of the |
| | | grouping but later|
| | | when the subclass |
| | | is instantiated |
| | | the key value must|
| | | be identified from|
| | | within the |
| | | grouping. |
+-------------------------------------------------------------------+
| object identifier | list::"key" | It is possible |
| | substatement | that the super- |
| Note: Attributes used | | class or abstract |
| as object identifier | | class contains the|
| are defined in UML by | | key attribute for |
| the attribute | | the instantiated |
| property | | subclass. |
| "partOfObjectKey". | | |
+-------------------------------------------------------------------+
| object identifier list| | The splitting of a|
| | | list attribute |
| Does not appear in the| | (marked as key) |
| UML when mapping to | | into a single key |
| YANG. | | attribute and an |
| | | additional list |
| | | attribute will be |
| | | done in UML during|
| | | Pruning and |
| | | Refactoring. i.e.|
| | | The mapping tool |
| | | will never get a |
| | | list attribute |
| | | which is part of |
| | | the object |
| | | identifier. |
+-------------------------------------------------------------------+
| objectCreationNotific-| "notification" | Goes beyond the |
| ation | statement | simple "a notific-|
| [YES/NO/NA] | | ation has to be |
| | | sent": a tool can |
| | | construct the sig-|
| | | ature of the noti-|
| | | cation by reading |
| | | the created |
| | | object. |
+-------------------------------------------------------------------+
| objectDeletionNotific-| "notification" | Goes beyond the |
| ation | statement | simple "a notific-|
| [YES/NO/NA] | | ation has to be |
| | | sent": a tool can |
| | | construct the sig-|
| | | ature of the noti-|
| | | cation by reading |
| | | the deleted |
| | | object. (i.e. not |
| | | necessary to |
| | | provide the |
| | | attributes of the |
| | | deleted object). |
+-------------------------------------------------------------------+
| support | "if-feature" | Support and |
| | substatement | condition belong |
+-----------------------+ | together. If the |
| condition | | "support" is cond-|
| | | itional, then the |
| | | "condition" |
| | | explains the cond-|
| | | itions under which|
| | | the class has to |
| | | be supported. |
+-------------------------------------------------------------------+
| operation | "action" | YANG 1.0 supports |
| | substatement | only rpc -> add |
| | | prefix to the rpc |
| | | name; i.e. |
| | | objectClass::rpc; |
| | | "action" requires |
| | | YANG 1.1 |
+-------------------------------------------------------------------+
| XOR | "choice" | |
| | substatement | |
+-------------------------------------------------------------------+
| muliplicity on | list::"min-elements" | min-elements |
| association | "max-elements" | default = 0 |
| | substatements | max-elements |
| | | default=unbounded|
| | | mandatory |
| | | default=false |
+-------------------------------------------------------------------+
| Conditional PACs | container::presence" | |
| | substatement | |
+-------------------------------------------------------------------+
| hyperlink?? | "reference" | Papyrus doesn't |
| | substatement | support hyperlinks|
+-------------------------------------------------------------------+
| lifecycle stereotypes | "status" | UML: |
| | substatement | <<Example>>, |
| | | <<Experimental>>, |
| | | <<Faulty>>, |
| | |<<LikelyToChange>>,|
| | | <<Deprecated>>, |
| | | <<Obsolete>>, |
| | | <<Preliminary>> |
| | | YANG: |
| | | "current", |
| | | "deprecated", |
| | | "obsolete", |
| | | default="current" |
+-------------------------------------------------------------------+
| constraint property | list::"unique" | UML is not able to|
| | substatement | define a group |
| | | of attributes to be
| | | unique as YANG can|
| | | do using the |
| | | "unique" |
| | | substatement. |
+-------------------------------------------------------------------+
| abstract superclass/ | "uses" substatement | use of a complex |
| inheritance | | data type as the |
| | | type of the |
| complex attribute | | attribute; e.g., |
| | | date and time, |
| | | object creation |
| | | data |
| | | It is possible that
| | | the superclass or |
| | | abstract class |
| | | contains the key |
| | | attribute for the |
| | | instantiated |
| | | subclass. |
+-------------------------------------------------------------------+
| {<constraint>} | "when" substatement | |
+-------------------------------------------------------------------+
Figure 1: Mapping of Object Classes
Figure 2: Example of Abstract Object Class Mapping (Available in PDF or HTML versions)
Figure 3: Example of Non-Abstract Object Class Mapping (Available in PDF or HTML versions)
+-------------------------------------------------------------------+
| Attribute --> "leaf" (single) or "leaf list" (multiple) |
| statement |
+-------------------------------------------------------------------+
| UML Artifact | YANG Artifact | Comment |
+-------------------------------------------------------------------+
| documentation | "description" | Multiple "applied |
| "Applied comments" | substatement | comments" defined |
| (carried in XMI as | | in UML, need to be|
| "ownedComment") | | collapsed into a |
| | | single |
| | | "description" |
| | | substatement. |
+-------------------------------------------------------------------+
| type | "type" substatement | |
| | (built-in or derived) | |
+-------------------------------------------------------------------+
| readOnly | "config" substatement | config |
| | (false) | default = true |
+-------------------------------------------------------------------+
| isOrdered | "ordered-by" | ordered-by |
| | substatement | default = system |
| |("system" or "user") | |
+-------------------------------------------------------------------+
| multiplicity | "mandatory" or | min-elements |
| | "min-elements" and | default = 0 |
| | "max-elements" | max-elements |
| | substatements | default=unbounded|
| | [0..1]=>no mapping | mandatory |
| | needed; is default | default=false |
| | substatement=false | |
| | [1]=>mandatory | |
| | substatement=true | |
| | [0..x]=> no mapping | |
| | needed; is default | |
| | [1..x]=> min-elements | |
| | substatement = 1 | |
| | [0..3]=> max-elements | |
| | substatement = 3 | |
+-------------------------------------------------------------------+
| defaultValue | "default" | If a default value|
| | substatement | exists and it is |
| | | the desired value,|
| | | the parameter does|
| | | not have to be |
| | | explicitly config-|
| | | ured by the user. |
+-------------------------------------------------------------------+
| isInvariant | "extension" | |
| | substatement -> | |
| | ompExt:isInvariant | |
+-------------------------------------------------------------------+
| valueRange | "pattern", "range", or| |
| | "length" substatement | |
| | of "type" substatement| |
+-------------------------------------------------------------------+
| passedByReference | if passedByReference =| Relevant only to |
| | true -> type leafref {| attributes that |
| | path "/<object>/ | have an object |
| | <objectidentifier>"} | class defined as |
| | | their type. |
| | if passedByReference =| |
| | false -> either "list"| |
| | statement (key | |
| | property, multiple | |
| | instances) or | |
| | "container" statement(| |
| | single instance) | |
+-------------------------------------------------------------------+
| partOfObjectKey > 0 | list::"key" | It is possible that
| | substatement | the (abstract) |
| | | superclass contains
| | | the key attribute |
| | | for the |
| | | instantiated |
| | | subclass. |
+-------------------------------------------------------------------+
| unit | "units" substatement | Need to discuss |
| | | with the YANG |
| | | community about a |
| | | standard way to |
| | | express units (e.g.
| | | kilobitspersecond,|
| | | kbit/s, |
| | | kilobits/second, |
| | | kbit/sec). |
| | | |
| | | Current |
| | | description of the|
| | | new "unit" property
| | | in OpenModelProfile
| | | v0.2.1 is: |
| | | "This optional |
| | | property contains a
| | | textual definition|
| | | of the unit |
| | | associated with the
| | | attribute value. |
| | | The spelling of the
| | | unit, including the
| | | ones beyond SI |
| | | scope, shall be in|
| | | accordance to the |
| | | NIST Publication |
| | | 811 "Guide for the|
| | | Use of the |
| | | International |
| | | System of Units |
| | | (SI)" (http://www.|
| | | nist.gov/pml/pubs/|
| | | sp811/index.cfm), |
| | | section 9 "Rules |
| | | and Style |
| | | Conventions for |
| | | Spelling Unit |
| | | Names"." |
+-------------------------------------------------------------------+
| support | For conditional | Support and |
| | support only: | condition belong |
+-----------------------+ | together. If the |
| condition | "if-feature" | "support" is cond-|
| | substatement | itional, then the |
| | | "condition" |
| | "when" substatement if| explains the cond-|
| | condition can be | itions under which|
| | formalized as XPath | the class has to |
| | expression (i.e., it | be supported. |
| | is conditioned by the | |
| | value of another | |
| | attribute) | |
+-------------------------------------------------------------------+
| error notfication?? | "must" | |
| | substatement | |
+-------------------------------------------------------------------+
| hyperlink?? | "reference" | Papyrus doesn't |
| | substatement | support hyperlinks|
+-------------------------------------------------------------------+
| lifecycle stereotypes | "status" | "current" |
| | substatement | "deprecated" |
| | | "obsolete" |
| | | default="current"|
+-------------------------------------------------------------------+
| {<constraint>} | "when" substatement | |
+-------------------------------------------------------------------+
Figure 4: Mapping of Attributes
Figure 5: Example of Attribute Mapping (Available in PDF or HTML versions)
+-------------------------------------------------------------------+ | Types | +-------------------------------------------------------------------+ | UML Artifact | YANG Artifact | Comment | +-------------------------------------------------------------------+ | Primitive Type | Built-In Type if | e.g., Integer | | | defined; otherwise ?? |new built-in type??| +-------------------------------------------------------------------+ | Enumeration | "enum" statement | | +-------------------------------------------------------------------+ | Basic Data Type | "typeDef" statement | e.g., MAC address,| | | | IPv4 Address | +-------------------------------------------------------------------+ | Complex Data Type | "grouping" statement | e.g., date-time | | | | object creation | | | | data | +-------------------------------------------------------------------+
Figure 6: Mapping of Types
+-------------------------------------------------------------------+ | Primitive Type -> new built-in type?? | +-------------------------------------------------------------------+ | UML Artifact | YANG Artifact | Comment | +-------------------------------------------------------------------+ | documentation | Description field | | | (carried in XMI as | | | | "ownedComment") | | | +-------------------------------------------------------------------+ | Integer | int64 | | +-------------------------------------------------------------------+ | Boolean | boolean | | +-------------------------------------------------------------------+ | String | string | | +-------------------------------------------------------------------+ | Real | ?? | | +-------------------------------------------------------------------+
Figure 7: Mapping of Primitive Types
+-------------------------------------------------------------------+ | Enumeration Type -> "enum" statement | | typedef for reusable (indirect usage) enumerations | | identity statement? | +-------------------------------------------------------------------+ | UML Artifact | YANG Artifact | Comment | +-------------------------------------------------------------------+ | documentation | "description" | Multiple "applied | | "Applied comments" | substatement | comments" defined | | (carried in XMI as | | in UML, need to be| | "ownedComment") | | collapsed into a | | | | single | | | | "description" | | | | substatement. | +-------------------------------------------------------------------+ | literal integer | "value" | | | | substatement | | +-------------------------------------------------------------------+ | hyperlink?? | "reference" | Papyrus doesn't | | | substatement | support hyperlinks| +-------------------------------------------------------------------+ | lifecycle stereotypes | "status" | "current", | | | substatement | "deprecated", | | | | "obsolete" | | | | default=current | +-------------------------------------------------------------------+ | ?? | "if-feature" statement| | +-------------------------------------------------------------------+
Figure 8: Mapping of Enumeration Types
Figure 9: Example of Enumeration Type Mapping (Available in PDF or HTML versions)
+-------------------------------------------------------------------+ | Basic Data Type -> "typeDef" statement | +-------------------------------------------------------------------+ | UML Artifact | YANG Artifact | Comment | +-------------------------------------------------------------------+ | documentation | "description" | Multiple "applied | | "Applied comments" | substatement | comments" defined | | (carried in XMI as | | in UML, need to be| | "ownedComment") | | collapsed into a | | | | single | | | | "description" | | | | substatement. | +-------------------------------------------------------------------+ | type | "type" substatement | | | | (built-in type) | | +-------------------------------------------------------------------+ | defaultValue | "default" | If a default value| | | substatement | exists and it is | | | | the desired value,| | | | the parameter does| | | | not have to be | | | | explicitly config-| | | | ured by the user. | +-------------------------------------------------------------------+ | hyperlink?? | "reference" | Papyrus doesn't | | | substatement | support hyperlinks| +-------------------------------------------------------------------+ | lifecycle stereotypes | "status" | "current", | | | substatement | "deprecated", | | | | "obsolete" | | | | default=current | +-------------------------------------------------------------------+ | unit | "units" statement | | +-------------------------------------------------------------------+
Figure 10: Mapping of Basic Data Types
Figure 11: Example of Basic Data Type Mapping (Available in PDF or HTML versions)
+-------------------------------------------------------------------+ | Complex Data Type -> "grouping" statement | +-------------------------------------------------------------------+ | UML Artifact | YANG Artifact | Comment | +-------------------------------------------------------------------+ | documentation | "description" | Multiple "applied | | "Applied comments" | substatement | comments" defined | | (carried in XMI as | | in UML, need to be| | "ownedComment") | | collapsed into a | | | | single | | | | "description" | | | | substatement. | +-------------------------------------------------------------------+ | not used | "action" substatement | | +-------------------------------------------------------------------+ | XOR | "choice" | | | | substatement | | +-------------------------------------------------------------------+ | hyperlink?? | "reference" | Papyrus doesn't | | | substatement | support hyperlinks| +-------------------------------------------------------------------+ | lifecycle stereotypes | "status" | "current", | | | substatement | "deprecated", | | | | "obsolete" | | | | default=current | +-------------------------------------------------------------------+ | complex attribute | "uses" statement | | +-------------------------------------------------------------------+
Figure 12: Mapping of Complex Data Types
Leaf and leaf-list can only use built-in types, typeDef types or enumerations in their type substatement; i.e., not groupings. Complex data types with more than one item (e.g., name value pair) can only be defined using groupings. Groupings can only be used by grouping, container and list statements.
Figure 13: Example of Complex Data Type Mapping (Available in PDF or HTML versions)
+-------------------------------------------------------------------+ | Associations | +-------------------------------------------------------------------+ | UML Artifact | YANG Artifact | Comment | +-------------------------------------------------------------------+ | Inheritance | abstract superclass: | Multiple | | | "grouping" statement | inheritance can | | | | also be mapped | | | concrete superclass: | using "groupings" | | | "augment" statement | Need to define | | | | when augment is | | | | used. Note: | | | | Augmentation can | | | | be conditional. | +-------------------------------------------------------------------+ | Composition with | "container" statement | How to map "passed| | (aggregation= | containing "list" | by reference"?? | | 'composite') | statement(s) (multiple| | | "passed by value" | contained instances) | | | | or "container" state- | | | | ment(s) (single | | | | contained instances) | | +-------------------------------------------------------------------+ | Aggregation with | "leafref" statement | How to map "passed| | (aggregation='shared')| | by value"?? | | "passed by reference" | | | +-------------------------------------------------------------------+
Figure 14: Mapping of Associations
Figure 15: Association Mapping Example 1 (Available in PDF or HTML versions)
Figure 16: Association Mapping Example 2 (Available in PDF or HTML versions)
Figure 17: Association Mapping Example 3 (Available in PDF or HTML versions)
+-------------------------------------------------+
| UML |
+-------------------------------------------------+
| containment | association | inheritance |
+-------------------------------------------------------------------+
| YANG | nesting | X | | |
| +------------------------------------------------------------+
| | grouping | | | X |
| | | | |abstract superclasses|
| +------------------------------------------------------------+
| | augment | | | X |
| | | | |concrete superclasses|
| +------------------------------------------------------------+
| | leafref | | X | |
+-------------------------------------------------------------------+
Figure 18: Association Mapping Summary
+-------------------------------------------------------------------+ | UML Interface -> Container?? | +-------------------------------------------------------------------+ | documentation | "description" | Multiple "applied | | "Applied comments" | substatement | comments" defined | | (carried in XMI as | | in UML, need to be| | "ownedComment") | | collapsed into a | | | | single | | | | "description" | | | | substatement. | +-------------------------------------------------------------------+ | abstract | "grouping" statement | | +-------------------------------------------------------------------+ | support | "if-feature" | Support and | | | substatement | condition belong | +-----------------------+ | together. If the | | condition | | "support" is cond-| | | | itional, then the | | | | "condition" | | | | explains the cond-| | | | itions under which| | | | the class has to | | | | be supported. | +-------------------------------------------------------------------+
Figure 19: Mapping of Interfaces (grouping of operations
+-------------------------------------------------------------------+ | Operation -> "action" and "rpc" statements | | (RFC 6020: The difference between an action and an rpc is that an| | action is tied to a node in the data tree, whereas an rpc is | | associated at the module level.) | +-------------------------------------------------------------------+ | documentation | "description" | Multiple "applied | | "Applied comments" | substatement | comments" defined | | (carried in XMI as | | in UML, need to be| | "ownedComment") | | collapsed into a | | | | single | | | | "description" | | | | substatement. | +-------------------------------------------------------------------+ | pre-condition | "extension" | RFC 6020; During | | | substatement -> | the NETCONF | | | ompExt:preCondition | <edit-config> pro-| | | | cessing errors are| | | | already sent for: | | | | - Delete requests | | | | for non-existent| | | | data. | | | | - Create requests | | | | for existing | | | | data. | | | | - Insert requests | | | | with "before" or| | | | "after" para- | | | | meters that do | | | | not exist. | +-------------------------------------------------------------------+ | post-condition | "extension" | | | | substatement | | | | ompExt:postCondition | | +-------------------------------------------------------------------+ | input parameter | "input" substatement | | +-------------------------------------------------------------------+ | output parameter | "output" substatement | | +-------------------------------------------------------------------+ | operation exceptions | "extension" | | | | substatement | | | Internal Error | ompExt:operationExceptions | | Unable to Comply | | | Comm Loss | +--------------------------------------+ | | Invalid Input | | error-tag | error-app-tag | | | Not Implemented | +--------------------------------------+ | | Duplicate | | operation-failed | too-many-elements | | | Entity Not Found | | | too-few-elements | | | Object In Use | | | must-violation | | | Capacity Exceeded | +--------------------------------------+ | | Not In Valid State | | data-missing | instance-required | | | Access Denied | | | missing-choice | | | | +--------------------------------------+ | | | | bad-attribute | missing-instance | | | | +--------------------------------------+ | +-------------------------------------------------------------------+ | isOperationIdempotent | "extension" | | | | substatement | | | | ompExt:isOperationIdempotent | +-------------------------------------------------------------------+ | isAtomic | "extension" | Necessary?? Not in| | | substatement | UML Guidelines | | | ompExt:isAtomic | (TR-514); needs to| | | | be added?? | +-------------------------------------------------------------------+ | support | "if-feature" | Support and | | | substatement | condition belong | +-----------------------+ | together. If the | | condition | | "support" is cond-| | | | itional, then the | | | | "condition" | | | | explains the cond-| | | | itions under which| | | | the class has to | | | | be supported. | +-------------------------------------------------------------------+ | hyperlink?? | "reference" | Papyrus doesn't | | | substatement | support hyperlinks| +-------------------------------------------------------------------+ | lifecycle stereotypes | "status" | "current", | | | substatement | "deprecated", | | | | "obsolete" | | | | default=current | +-------------------------------------------------------------------+
Figure 20: Mapping of Operations
Figure 21: Operation Mapping Example (Available in PDF or HTML versions)
+-------------------------------------------------------------------+
| Operation Parameters |
+-------------------------------------------------------------------+
| documentation | "description" | Multiple "applied |
| "Applied comments" | substatement | comments" defined |
| (carried in XMI as | | in UML, need to be|
| "ownedComment") | | collapsed into a |
| | | single |
| | | "description" |
| | | substatement. |
+-------------------------------------------------------------------+
| direction | "input" or "output" | |
| | substatement | |
+-------------------------------------------------------------------+
| type | see mapping of | |
+-----------------------| attribute types |-------------------+
| isOrdered | (grouping, leaf, | |
+-----------------------| leaf-list, list, |-------------------+
| multiplicity | typedef, uses) | |
+-----------------------| |-------------------+
| defaultValue | | |
+-----------------------| |-------------------+
| valueRange | | |
+-------------------------------------------------------------------+
| passedByReference | if passedByReference =| Relevant only to |
| | true -> type leafref {| attributes that |
| | path "/<object>/ | have an object |
| | <objectidentifier>"} | class defined as |
| | | their type. |
| | if passedByReference =| |
| | false -> either "list"| |
| | statement (key | |
| | property, multiple | |
| | instances) or | |
| | "container" statement(| |
| | single instance) | |
+-------------------------------------------------------------------+
| support | "if-feature" | Support and |
| | substatement not | condition belong |
+-----------------------+ defined for input and | together. If the |
| condition | output substatements | "support" is cond-|
| | in YANG?? | itional, then the |
| | | "condition" |
| | | explains the cond-|
| | | itions under which|
| | | the class has to |
| | | be supported. |
+-------------------------------------------------------------------+
| XOR | "choice" | |
| | substatement | |
+-------------------------------------------------------------------+
| error notification?? | "must" | |
| | substatement | |
+-------------------------------------------------------------------+
| complex parameter | "uses" | |
| | substatement | |
+-------------------------------------------------------------------+
Figure 22: Mapping of Operation Parameters
Figure 23: Parameter Mapping Example (Available in PDF or HTML versions)
+-------------------------------------------------------------------+ | Signal -> "notification" statement | +-------------------------------------------------------------------+ | documentation | "description" | Multiple "applied | | "Applied comments" | substatement | comments" defined | | (carried in XMI as | | in UML, need to be| | "ownedComment") | | collapsed into a | | | | single | | | | "description" | | | | substatement. | +-------------------------------------------------------------------+ | support | "if-feature" | Support and | | | substatement | condition belong | +-----------------------+ | together. If the | | condition | | "support" is cond-| | | | itional, then the | | | | "condition" | | | | explains the cond-| | | | itions under which| | | | the class has to | | | | be supported. | +-------------------------------------------------------------------+ | XOR | "choice" | | | | substatement | | +-------------------------------------------------------------------+ | error notification?? | "must" | | | | substatement | | +-------------------------------------------------------------------+ | hyperlink?? | "reference" | Papyrus doesn't | | | substatement | support hyperlinks| +-------------------------------------------------------------------+ | lifecycle stereotypes | "status" | "current", | | | substatement | "deprecated", | | | | "obsolete" | | | | default=current | +-------------------------------------------------------------------+ | attributes | see mapping of | | | | attribute types | | | | (grouping, leaf, | | | | leaf-list, container,| | | | list, typedef, uses) | | +-------------------------------------------------------------------+ | complex attribute | "uses" | | | | substatement | | +-------------------------------------------------------------------+
Figure 24: Mapping of Notifications
Figure 25: Notification Mapping Example (Available in PDF or HTML versions)
+-------------------------------------------------------------------+ | UML Lifecycle | +-------------------------------------------------------------------+ | lifecycle stereotypes | "status" | YANG: "current", | | | substatement | "deprecated", | | | | "obsolete" | | | | default=current | | | | | | | | UML: <<Example>>, | | | | <<Experimental>>, | | | | <<Faulty>>, | | | | <<Preliminary>>, | | | | <<Obsolete>>, | | | | <<LikelyToChange>>| | | | | | | | How to map or | | | | enhance?? | +-------------------------------------------------------------------+
Figure 26: Mapping of Lifecycle
+-------------------------------------------------------------------+ | UML Lifecycle | +-------------------------------------------------------------------+ | Conditional Package | "container" statement | | | | with | | | | "presence" | | | | substatement | | +-------------------------------------------------------------------+ | Package?? | Submodule | | +-------------------------------------------------------------------+
Figure 27: Other Mappings
Many common types (primitive and complex) are already defined in YANG. E.g., ietf-inet-types, ietf-yang-types (others to be investigated):
+ ietf-inet-type
+ domain name and URI types + ietf-yang-types
- DomainName - Counter32
- Uri - Counter64
- <<Union>> Host - DateAndTime
+ types related to - DottedQuad
IP addresses and hostnames - Gauge32
- Ipv4Address - Gauge64
- Ipv4AddressNoZone - HexString
- Ipv4Prefix - MacAddress
- Ipv6Address - ObjectIdentifier
- Ipv6AddressNoZone - ObjectIdentifier128
- Ipv6Prefix - PhysAddress
- <<Union>> IpAddress - Timestamp
- <<Union>> IpAddressNoZone - Timeticks
- <<Union>> IpPrefix - Uuid
+ types related to protocol fields - Xpath1.0
- IpVersion - YangIdentifier
- DSCP - ZeroBasedCounter32
- IpV6FlowLabel - ZeroBasedCounter64
- PortNumber
Figure 28: Re-engineered Example
It is proposed to define for the commonly used YANG types corresponding UML primitive or complex data types respectively. These types will be available (by default) for use in all UML information models. This "re-engineering" needs to be done without making the UML models YANG-depended.
Figure 29: IP Address Mapping Example (Available in PDF or HTML versions)
YANG 1.0 is approved and defined in RFC6020 [RFC6020].
YANG 1.1 is not currently approved and its definition is ongoing in draft-ietf-netmod-rfc6020bis [I-D.ietf-netmod-rfc6020bis]. Main enhancements are the action and anydata statements.
Need to define mapping rules for UML package into YANG modules or the new draft YANG package statement (draft-bierman-netmod-yang-package [I-D.bierman-netmod-yang-package])?
Figure 30: Combination of different Associations Example (Available in PDF or HTML versions)
As YANG defines hierarchical data store, any instances that need to store recursive containment will require translation. A mapping between object-oriented store and a hierarchical store is possible; however, there is more than one option:
Figure 31: Recursion Mapping Example 1 (Available in PDF or HTML versions)
Figure 32: Recursion Mapping Example 2 (Available in PDF or HTML versions)
Use the "presence" property of the container statement?
Note: An example of this usage is given in the "Data nodes for the operational state of IP on interfaces." within ietf-ip.yang RFC7277 [RFC7277].
Figure 33: Mapping of Conditional Packages (Available in PDF or HTML versions)
Use the "choice" property of the container statement.
The UML Modeling Guidelines [ONF-TR-514] define support and condition for all UML artifacts (M - Mandatory, O - Optional, C - Conditional, CM - Conditional-Mandatory, CO - Conditional-Optional). Support qualifies the support of the artifact at the management interface. Condition contains the condition for the condition-related support qualifiers.
M - Mandatory maps to the "mandatory" substatement in choice and leaf or to the "min-elements" substatement in leaf-list and list.
O - Optional need not be mapped since the per default the "mandatory" and "min-elements" substaments define optional.
All conditional UML support qualifiers are mapped to the "if-feature" substatement.
Figure 34: Support and Condition Mapping Example (Available in PDF or HTML versions)
Figure 35: Example UML to YANG Mapping (Available in PDF or HTML versions)
Figure 36: Example XMI (Papyrus) to YANG Mapping (Available in PDF or HTML versions)
This memo includes no request to IANA.
This document defines defines guidelines for translation of data modeled with UML to YANG. As such, it doesn't contribute any new security issues beyond those discussed in Sec. 16 of RFC6020 [RFC6020].
The YANG data schema (in tree format) shown below was extracted from dharini-netmod-g-698-2-yang [I-D.dharini-netmod-g-698-2-yang] and represents the same data as UML model appearing in Figure 39 after the tree format. Note: The color code used in the tree format corresponds to the color code used in the UML class diagram.
Figure 37: Interfaces Tree (Available in PDF or HTML versions)
Figure 38: Notifications Tree (Available in PDF or HTML versions)
Figure 39: Interfaces UML Model (Available in PDF or HTML versions)