LBaaS Layer 7 rules

Launchpad blueprint:

https://blueprints.launchpad.net/neutron/+spec/lbaas-l7-rules

Layer 7 switching takes its name from the OSI model, indicating that the device switches requests based on layer 7 (application) data. Layer 7 switching is also known as “request switching”, “application switching”, and “content based routing”. A layer 7 switch presents to the outside world a “virtual server” that accepts requests on behalf of a number of servers and distributes those requests based on policies that use application data to determine which server should service which request. This allows for the application infrastructure to be specifically tuned/optimized to serve specific types of content. For example, one server can be tuned to serve only images, another for execution of server-side scripting languages like PHP and ASP, and another for static content such as HTML, CSS and JavaScript.

Problem Description

Use Cases:

  1. Redirect traffic to a Pool that supports static content (HTML, CSS)
  2. Redirect traffic to a Pool that serves images (jpg, png, etc)

Proposed Change

Extend the LBaaS API and support Layer 7 switching.

L7 Entities:
  1. L7Rule - Set of attributes that defines which part of the request should be matched and how it should be matched.
  2. L7Policy - A collection of L7Rules. Holds the action that should be performed when the rules are matched.(Redirect to Pool, Redirect to URL, Reject). L7Policy holds a Listener id, so a Listner can evaluate a collection of L7Policies. L7Policy will return ‘true’ when all of the L7Rules that belong to this L7Policy are matched. L7Policies under a specific Listener are ordered and the first l7Policy that returns a match will be executed. When none of the policies match the request gets forwarded to listener.default_pool_id

Data Model Impact

Model:

+--------------------+        +--------------------+
| Listener           |        | L7Policy           |
+--------------------+        +--------------------+
|                    |        |                    |
|   id               |        |   id               |
|   other attributes +--------+   action           |
|                    |        |   pool id          |
|                    |        |   redirect url     |
|                    |        |   listener id      |
+--------------------+        |   index            |
                              |                    |
                              |                    |
                              +-----------------+--+
                                                |
                                                |
                             +------------------+--+
                             | L7Rule              |
                             +---------------------+
                             |                     |
                             |  id                 |
                             |  l7 policy id       |
                             |  type               |
                             |  compare type       |
                             |  key                |
                             |  value              |
                             |                     |
                             +---------------------+

Two new entities are introduced: L7Rule and L7Policy The L7Policy is a container of L7Rules. The L7Policy contains a reference to a Listener

  1. L7Rule object Data Model.
Field Type Null Key Default
id string(36) NO PRI  
l7_policy_id string(36) NO FK  
type Enum (*) NO    
compare_type Enum (*) NO    
key string(36) NO    
value string(36) YES    
  • type values
    • Hostname
    • Path
    • FileType: This is the file extension. Examples: txt, jpg, png, xls
      A rule that is looking for text files will look like: type = FileType, compare_type=EqualTo, value = txt
    • Header
    • Cookie: This is the value of a specific cookie
      A rule that is looking for a cookie named ‘department’ with the value starting with ‘finance-‘ will look like: type = Cookie, compare_type=StartsWith, key = department value = finance-
  • compare_type values
  • Regexp
  • StartsWith
  • EndsWith
  • Contains
  • EqualTo
  • GreaterThan
  • LessThan
  1. L7Policy object Data Model.
Field Type Null Key Default
id string(36) NO PRI  
listener_id string(36) NO FK  
action Enum (*) NO    
pool_id string(36) YES    
redirect_url string(256) YES    
index int NO    
  • action: [Reject,RedirectToURL,RedirectToPool]
  • If action is RedirectToURL redirect_url can not be null
  • If action is RedirectToPool pool_id can not be null
  • Index
  • If total policies for this listener is less than index, append to end of list.
  • Index numbering starts with 0
  • If policy with same index number exists, insert the new policy at that index number and increment all policy indexes for this listener with an equal or higher index value.
  • Not specifying an index appends the policy to the list.

REST API Impact

l7rule-create Create a L7Rule for a given tenant.

Request

POST /v2.0/l7rules Accept: application/json
{
  "l7rule":{
    "l7_policy_id": "6b96ff0cb17a4b859e1e575d221683c5",
    "type":"Header",
    "compare_type":"StartsWith",
    "key":'department',
    "value":"HR"
  }
}

Response

{
  "l7rule":{
  "id": "6b96ff0cb17a4b859e1e575d221683d7",
  "l7_policy_id": "6b96ff0cb17a4b859e1e575d221683c5",
  "type":"Header",
  "compare_type":"StartsWith",
  "key":'department',
  "value":"HR",
  "tenant_id":"6b96ff0cb17a4b859e1e575d2216845"
  }
}

l7rule-show Show information of a given L7Rule.

Request

GET /v2.0/l7rules/6b96ff0cb17a4b859e1e575d221683d7 Accept: application/json

Response

{
  "l7rule":{
  "id": "6b96ff0cb17a4b859e1e575d221683d7",
  "l7_policy_id": "6b96ff0cb17a4b859e1e575d221683c5",
  "type":"Header",
  "compare_type":"StartsWith",
  "key":'department',
  "value":"HR"
  "tenant_id":"6b96ff0cb17a4b859e1e575d2216845"
  }
}

l7rule-delete Delete a given L7Rule.

Request

DELETE /v2.0/l7rules/6b96ff0cb17a4b859e1e575d221683d7 Accept: application/json

l7policy-create Create a L7Policy for a given tenant.

POST /v2.0/l7policies Accept: application/json
{
  "l7policy":{
  "listener_id": "6b96ff0cb17a4b859e1e575d221683c5",
  "action":"RedirectToPool",
  "pool_id":6b96ff0cb17a4b859e1e575d22168399,
  "index": 2
  }
}

Response

{
  "l7policy":{
  "id": "6b96ff0cb17a4b859e1e575d221683d7",
  "listener_id": "6b96ff0cb17a4b859e1e575d221683c5",
  "action":"RedirectToPool",
  "pool_id":6b96ff0cb17a4b859e1e575d22168399,
  "tenant_id":"6b96ff0cb17a4b859e1e575d2216845",
  "index": 2
  }
}

l7policy-show Show information of a given L7Policy.

Request

GET /v2.0/l7policies/6b96ff0cb17a4b859e1e575d221683d7 Accept: application/json

Response

{
  "l7policy":{
  "id": "6b96ff0cb17a4b859e1e575d221683d7",
  "listener_id": "6b96ff0cb17a4b859e1e575d221683c5",
  "action":"RedirectToPool",
  "pool_id":6b96ff0cb17a4b859e1e575d22168399,
  "tenant_id":"6b96ff0cb17a4b859e1e575d2216845",
  "index": 2
  }
}

l7policy-delete Delete a given L7Policy.

Request

DELETE /v2.0/l7policies/6b96ff0cb17a4b859e1e575d221683d7 Accept: application/json

Security Impact

None.

Notifications Impact

None.

Other End User Impact

None.

Performance Impact

None.

IPv6 Impact

None

Other Deployer Impact

None.

Developer Impact

None.

Community Impact

This change has been in review since Juno. Much discussion has taken place over IRC and the mailing list.

Alternatives

None.

Implementation

Assignee(s)

Primary assignee:
https://launchpad.net/~avishayb
Other contributors:
TBD

Work Items

  • REST API
  • DB Schema
  • LBaaS plugin and driver API
  • CLI update

Dependencies

Testing

Tempest Tests

  • DB mixin and schema tests
  • LBaaS Plugin with mocked driver end-to-end tests
  • Tempest tests
  • CLI tests

Functional Tests

  • Specific driver tests for each existing driver supporting L7 switching

API Tests

  • REST API and attributes validation tests

Documentation Impact

User Documentation

  • Neutron CLI should be modified with L7Rule and L7Policy entities

Developer Documentation

  • Neutron API should be modified with L7Rule and L7Policy entities