docs/developer-guide/didm-developer-guide.rst

   1 .. _didm-developer-guide:
   2
   3 DIDM Developer Guide
   4 ====================
   5
   6 Overview
   7 --------
   8
   9 The Device Identification and Driver Management (DIDM) project addresses
  10 the need to provide device-specific functionality. Device-specific
  11 functionality is code that performs a feature, and the code is
  12 knowledgeable of the capability and limitations of the device. For
  13 example, configuring VLANs and adjusting FlowMods are features, and
  14 there may be different implementations for different device types.
  15 Device-specific functionality is implemented as Device Drivers. Device
  16 Drivers need to be associated with the devices they can be used with. To
  17 determine this association requires the ability to identify the device
  18 type.
  19
  20 DIDM Architecture
  21 -----------------
  22
  23 The DIDM project creates the infrastructure to support the following
  24 functions:
  25
  26 -  **Discovery** - Determination that a device exists in the controller
  27    management domain and connectivity to the device can be established.
  28    For devices that support the OpenFlow protocol, the existing
  29    discovery mechanism in OpenDaylight suffices. Devices that do not
  30    support OpenFlow will be discovered through manual means such as the
  31    operator entering device information via GUI or REST API.
  32
  33 -  **Identification** – Determination of the device type.
  34
  35 -  **Driver Registration** – Registration of Device Drivers as routed
  36    RPCs.
  37
  38 -  **Synchronization** – Collection of device information, device
  39    configuration, and link (connection) information.
  40
  41 -  **Data Models for Common Features** – Data models will be defined to
  42    perform common features such as VLAN configuration. For example,
  43    applications can configure a VLAN by writing the VLAN data to the
  44    data store as specified by the common data model.
  45
  46 -  **RPCs for Common Features** – Configuring VLANs and adjusting
  47    FlowMods are example of features. RPCs will be defined that specify
  48    the APIs for these features. Drivers implement features for specific
  49    devices and support the APIs defined by the RPCs. There may be
  50    different Driver implementations for different device types.
  51
  52 Key APIs and Interfaces
  53 -----------------------
  54
  55 .. _didm-flow-objective-api:
  56
  57 FlowObjective API
  58 ~~~~~~~~~~~~~~~~~
  59
  60 Following are the list of the APIs to create the flow objectives to
  61 install the flow rule in OpenFlow switch in pipeline agnostic way.
  62 Currently these APIs are getting consumed by Atrium project.
  63
  64 Install the Forwarding Objective:
  65
  66 ``http://<CONTROLLER-IP>:8181/restconf/operations/atrium-flow-objective:forward``
  67
  68 Install the Filter Objective
  69
  70 ``http://<CONTROLLER-IP>:8181/restconf/operations/atrium-flow-objective:filter``
  71
  72 Install the Next Objective:
  73
  74 ``http://<CONTROLLER-IP>:8181/restconf/operations/atrium-flow-objective:next``
  75
  76 Flow mod driver API
  77 ~~~~~~~~~~~~~~~~~~~
  78
  79 This release includes a flow mod driver for the HP 3800. This
  80 driver adjusts the flows and push the same to the device. This API takes
  81 the flow to be adjusted as input and displays the adjusted flow as
  82 output in the REST output container. Here is the REST API to adjust and
  83 push flows to HP 3800 device:
  84
  85 ::
  86
  87     http://<CONTROLLER-IP:8181>/restconf/operations/openflow-feature:adjust-flow
  88
  89 Here is an example of an ARP flow and how it gets adjusted and pushed to
  90 device HP3800:
  91
  92 **adjust-flow input.**
  93
  94 ::
  95
  96     <?xml version="1.0" encoding="UTF-8" standalone="no"?>
  97     <input xmlns="urn:opendaylight:params:xml:ns:yang:didm:drivers:openflow" xmlns:opendaylight-inventory="urn:opendaylight:inventory">
  98       <node>/opendaylight-inventory:nodes/opendaylight-inventory:node[opendaylight-inventory:id='openflow:673249119553088']</node>
  99         <flow>
 100           <match>
 101             <ethernet-match>
 102                 <ethernet-type>
 103                     <type>2054</type>
 104                 </ethernet-type>
 105             </ethernet-match>
 106           </match>
 107           <flags>SEND_FLOW_REM</flags>
 108           <priority>0</priority>
 109           <flow-name>ARP_FLOW</flow-name>
 110           <instructions>
 111             <instruction>
 112                 <order>0</order>
 113                 <apply-actions>
 114                     <action>
 115                         <order>0</order>
 116                         <output-action>
 117                             <output-node-connector>CONTROLLER</output-node-connector>
 118                             <max-length>65535</max-length>
 119                         </output-action>
 120                     </action>
 121                     <action>
 122                         <order>1</order>
 123                         <output-action>
 124                             <output-node-connector>NORMAL</output-node-connector>
 125                             <max-length>65535</max-length>
 126                         </output-action>
 127                     </action>
 128                 </apply-actions>
 129             </instruction>
 130           </instructions>
 131           <idle-timeout>180</idle-timeout>
 132           <hard-timeout>1800</hard-timeout>
 133           <cookie>10</cookie>
 134         </flow>
 135     </input>
 136
 137 In the output, you can see that the table ID has been identified for the
 138 given flow and two flow mods are created as a result of adjustment. The
 139 first one is to catch ARP packets in Hardware table 100 with an action
 140 to goto table 200. The second flow mod is in table 200 with actions:
 141 output normal and output controller.
 142
 143 **adjust-flow output.**
 144
 145 ::
 146
 147     {
 148       "output": {
 149         "flow": [
 150           {
 151             "idle-timeout": 180,
 152             "instructions": {
 153               "instruction": [
 154                 {
 155                   "order": 0,
 156                   "apply-actions": {
 157                     "action": [
 158                       {
 159                         "order": 1,
 160                         "output-action": {
 161                           "output-node-connector": "NORMAL",
 162                           "max-length": 65535
 163                         }
 164                       },
 165                       {
 166                         "order": 0,
 167                         "output-action": {
 168                           "output-node-connector": "CONTROLLER",
 169                           "max-length": 65535
 170                         }
 171                       }
 172                     ]
 173                   }
 174                 }
 175               ]
 176             },
 177             "strict": false,
 178             "table_id": 200,
 179             "flags": "SEND_FLOW_REM",
 180             "cookie": 10,
 181             "hard-timeout": 1800,
 182             "match": {
 183               "ethernet-match": {
 184                 "ethernet-type": {
 185                   "type": 2054
 186                 }
 187               }
 188             },
 189             "flow-name": "ARP_FLOW",
 190             "priority": 0
 191           },
 192           {
 193             "idle-timeout": 180,
 194             "instructions": {
 195               "instruction": [
 196                 {
 197                   "order": 0,
 198                   "go-to-table": {
 199                     "table_id": 200
 200                   }
 201                 }
 202               ]
 203             },
 204             "strict": false,
 205             "table_id": 100,
 206             "flags": "SEND_FLOW_REM",
 207             "cookie": 10,
 208             "hard-timeout": 1800,
 209             "match": {},
 210             "flow-name": "ARP_FLOW",
 211             "priority": 0
 212           }
 213         ]
 214       }
 215     }
 216
 217 API Reference Documentation
 218 ---------------------------
 219
 220 Go to
 221 http://${controller-ip}:8181/apidoc/explorer/index.html,
 222 and look under DIDM section to see all the available REST calls and
 223 tables