plugin

The xapi toolstack expects all plugins to support a basic query interface.

type debug_info = string

Debug context from the caller

type query_result = struct { ... }

properties of this implementation

Members:

Name	Type	Description
plugin	string	plugin name, used in the XenAPI as SR.type
name	string	short name
description	string	description
vendor	string	entity (e.g. company, project, group) which produced this implementation
copyright	string	copyright
version	string	version
required_api_version	string	minimum required API version
features	string list	features supported by this plugin
configuration	(string * string) list	key/description pairs describing required device_config parameters
required_cluster_stack	string list	the plugin requires one of these cluster stacks to be active

Plugin

Discover properties of this implementation. Every implementation must support the query interface or it will not be recognised as a storage plugin by xapi.

query

Query this implementation and return its properties. This is called by xapi to determine whether it is compatible with xapi and to discover the supported features.

Definition

OCaml example

Python example

Name	Direction	Type	Description
`dbg`	in	`debug_info`	Debug context from the caller
`query_result`	out	`query_result`	The properies of this implementation

Client

(* these directives only needed in a toplevel: *)
#require "xcp-api-client";;
#require "lwt";;
#require "lwt.syntax";;
#require "rpc.unix";;

open S
open Plugin
open Types

module Client = Plugin_client(struct
    include Lwt
    let rpc call = return (Rpc_client.do_rpc ~content_type:`XML ~path:"/" ~host:"127.0.0.1" ~port:80 call) (* TODO: Rpc_client needs to support Lwt *)
end)

let result = Client.query ~dbg:"string";;

Server

(* this line only needed in a toplevel: *)
#require "xcp-api-client";;

open S
open Plugin

module Plugin_myimplementation = functor(M: M) -> struct
    (* by default every operation will return a 'not implemented' exception *)
    include Plugin_skeleton(M)
    (* ... *)
    let query x =
        let open Types.Plugin.Query in
        let open Types in
        return (`Ok (Out.({ plugin = "string"; name = "string"; description = "string"; vendor = "string"; copyright = "string"; version = "string"; required_api_version = "string"; features = [ "string"; "string" ]; configuration = [ ("string", "string") ]; required_cluster_stack = [ "string"; "string" ] })))
    (* ... *)
end

Client

        
import xmlrpclib
import xapi
from storage import *

if __name__ == "__main__":
    c = xapi.connect()
    results = c.Plugin.query({ dbg: "string" })
    print (repr(results))

Server

        
import xmlrpclib
import xapi
from storage import *

class Plugin_myimplementation(Plugin_skeleton):
    # by default each method will return a Not_implemented error
    # ...
    def query(self, dbg):
        """Discover properties of this implementation. Every implementation  must support the query interface or it will not be recognised as  a storage plugin by xapi."""
        result = {}
        result["query_result"] = { "plugin": "string", "name": "string", "description": "string", "vendor": "string", "copyright": "string", "version": "string", "required_api_version": "string", "features": [ "string", "string" ], "configuration": { "string": "string" }, "required_cluster_stack": [ "string", "string" ] }
        return result
    # ...

ls

[ls dbg]: returns a list of attached SRs

Definition

OCaml example

Python example

Name	Direction	Type	Description
`dbg`	in	`debug_info`	Debug context from the caller
`srs`	out	`string list`	The attached SRs

Client

(* these directives only needed in a toplevel: *)
#require "xcp-api-client";;
#require "lwt";;
#require "lwt.syntax";;
#require "rpc.unix";;

open S
open Plugin
open Types

module Client = Plugin_client(struct
    include Lwt
    let rpc call = return (Rpc_client.do_rpc ~content_type:`XML ~path:"/" ~host:"127.0.0.1" ~port:80 call) (* TODO: Rpc_client needs to support Lwt *)
end)

let result = Client.ls ~dbg:"string";;

Server

(* this line only needed in a toplevel: *)
#require "xcp-api-client";;

open S
open Plugin

module Plugin_myimplementation = functor(M: M) -> struct
    (* by default every operation will return a 'not implemented' exception *)
    include Plugin_skeleton(M)
    (* ... *)
    let ls x =
        let open Types.Plugin.Ls in
        let open Types in
        return (`Ok (Out.([ "string"; "string" ])))
    (* ... *)
end

Client

        
import xmlrpclib
import xapi
from storage import *

if __name__ == "__main__":
    c = xapi.connect()
    results = c.Plugin.ls({ dbg: "string" })
    print (repr(results))

Server

        
import xmlrpclib
import xapi
from storage import *

class Plugin_myimplementation(Plugin_skeleton):
    # by default each method will return a Not_implemented error
    # ...
    def ls(self, dbg):
        """Discover properties of this implementation. Every implementation  must support the query interface or it will not be recognised as  a storage plugin by xapi."""
        result = {}
        result["srs"] = [ "string", "string" ]
        return result
    # ...

diagnostics

Returns a printable set of backend diagnostic information. Implementations are encouraged to include any data which will be useful to diagnose problems. Note this data should not include personally-identifiable data as it is intended to be automatically included in bug reports.

Definition

OCaml example

Python example

Name	Direction	Type	Description
`dbg`	in	`debug_info`	Debug context from the caller
`diagnostics`	out	`string`	A string containing loggable human-readable diagnostics information

Client

(* these directives only needed in a toplevel: *)
#require "xcp-api-client";;
#require "lwt";;
#require "lwt.syntax";;
#require "rpc.unix";;

open S
open Plugin
open Types

module Client = Plugin_client(struct
    include Lwt
    let rpc call = return (Rpc_client.do_rpc ~content_type:`XML ~path:"/" ~host:"127.0.0.1" ~port:80 call) (* TODO: Rpc_client needs to support Lwt *)
end)

let result = Client.diagnostics ~dbg:"string";;

Server

(* this line only needed in a toplevel: *)
#require "xcp-api-client";;

open S
open Plugin

module Plugin_myimplementation = functor(M: M) -> struct
    (* by default every operation will return a 'not implemented' exception *)
    include Plugin_skeleton(M)
    (* ... *)
    let diagnostics x =
        let open Types.Plugin.Diagnostics in
        let open Types in
        return (`Ok (Out.("string")))
    (* ... *)
end

Client

        
import xmlrpclib
import xapi
from storage import *

if __name__ == "__main__":
    c = xapi.connect()
    results = c.Plugin.diagnostics({ dbg: "string" })
    print (repr(results))

Server

        
import xmlrpclib
import xapi
from storage import *

class Plugin_myimplementation(Plugin_skeleton):
    # by default each method will return a Not_implemented error
    # ...
    def diagnostics(self, dbg):
        """Discover properties of this implementation. Every implementation  must support the query interface or it will not be recognised as  a storage plugin by xapi."""
        result = {}
        result["diagnostics"] = "string"
        return result
    # ...

exceptions

Name	Type	Description
Unimplemented	string	The operation has not been implemented