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

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