doc: add remote RPC access description

                         ioat.md \

                         iscsi.md \

                         jsonrpc.md \

                         jsonrpc_proxy.md \

                         lvol.md \

                         memory.md \

                         nvme.md \

# JSON-RPC Remote access {#jsonrpc_proxy}

SPDK provides a sample python script `rpc_http_proxy.py`, that provides http server which listens for JSON objects from users. It uses HTTP POST method to receive JSON objects including methods and parameters described in this chapter.

## Parameters

Name                    | Optional | Type        | Description

----------------------- | -------- | ----------- | -----------

server IP               | Required | string      | IP address that JSON objects shall be received on

server port             | Required | number      | Port number that JSON objects shall be received on

user name               | Required | string      | User name that will be used for authentication

password                | Required | string      | Password that will be used for authentication

RPC listen address      | Optional | string      | Path to SPDK JSON RPC socket. Default: /var/tmp/spdk.sock

## Example usage

`spdk/scripts/rpc_http_proxy.py 192.168.0.2 8000 user password`

## Returns

Error 401 - missing or incorrect user and/or password.

Error 400 - wrong JSON syntax or incorrect JSON method

Status 200 with resultant JSON object included on success.

## Client side

Below is a sample python script acting as a client side. It sends `get_bdevs` method with optional `name` parameter and prints JSON object returned from remote_rpc script.

~~~

import json

import requests

if __name__ == '__main__':

	payload = {'method': 'get_bdevs', 'params': {'name': 'Malloc0'}}

	url = 'http://192.168.0.2:8000/'

	req = requests.post(url,

                        data=json.dumps(payload),

                        auth=('user', 'password'),

                        verify=False,

                        timeout=30)

	print (req.json())

~~~

Output:

~~~

python client.py

[{u'num_blocks': 2621440, u'name': u'Malloc0', u'uuid': u'fb57e59c-599d-42f1-8b89-3e46dbe12641', u'claimed': True, u'driver_specific': {}, u'supported_io_types': {u'reset': True, u'nvme_admin': False, u'unmap': True, u'read': True, u'nvme_io': False, u'write': True, u'flush': True, u'write_zeroes': True}, u'qos_ios_per_sec': 0, u'block_size': 4096, u'product_name': u'Malloc disk', u'aliases': []}]

~~~

- @subpage bdev

- @subpage blobfs

- @subpage jsonrpc

- @subpage jsonrpc_proxy