python-redfish-library

Contents

• Description
• Installing
• Requirements
• Usage
• Release Process
• Copyright and License

Description

As of version 3.0.0, Python2 is no longer supported. If Python2 is required, redfish<3.0.0 can be specified in a requirements file.

REST (Representational State Transfer) is a web based software architectural style consisting of a set of constraints that focuses on a system's resources. The Redfish library performs GET, POST, PUT, PATCH and DELETE HTTP operations on resources within a Redfish service. Go to the wiki for more details.

Installing

pip install redfish

Building from zip file source

python setup.py sdist --formats=zip (this will produce a .zip file)
cd dist
pip install redfish-x.x.x.zip

Requirements

Ensure the system does not have the OpenStack "python-redfish" module installed on the target system. This module is using a conflicting package name that this library already uses. The module in question can be found here: https://pypi.org/project/python-redfish/

Required external packages:

jsonpatch<=1.24 ; python_version == '3.4'
jsonpatch ; python_version >= '3.5'
jsonpath_rw
jsonpointer
requests
requests-toolbelt
requests-unixsocket

If installing from GitHub, you may install the external packages by running:

pip install -r requirements.txt

Usage

A set of examples is provided under the examples directory of this project. In addition to the directives present in this paragraph, you will find valuable implementation tips and tricks in those examples.

Import the relevant Python module

For a Redfish conformant application import the relevant Python module.

For Redfish conformant application:

import redfish

Create a Redfish object

The Redfish object contains three required parameters:

• base_url: The address of the Redfish service (with scheme). Example: https://192.168.1.100. For Unix sockets, use the scheme http+unix://, followed by the percent-encoded filepath to the socket.
• username: The username for authentication.
• password: The password for authentication.

There are several optional parameters:

• default_prefix: The path to the Redfish service root. This is only used for initial connection and authentication with the service. The default value is /redfish/v1/.
• sessionkey: The session key to use with subsequent requests. This can be used to bypass the login step. The default value is None.
• cafile: The file path to the CA certificate that issued the Redfish service's certificate. The default value is None.
• timeout: The number of seconds to wait for a response before closing the connection. The default value is None.
• max_retry: The number of retries to perform an operation before giving up. The default value is 10.
• proxies: A dictionary containing protocol to proxy URL mappings. The default value is None. See Using proxies.
• check_connectivity: A boolean value to determine whether the client immediately attempts a connection to the base_url. The default is True.

To create a Redfish object, call the redfish_client method:

REDFISH_OBJ = redfish.redfish_client(base_url=login_host, username=login_account, \
                      password=login_password, default_prefix='/redfish/v1/')

Login to the service

After creating the REDFISH_OBJ, perform the login operation to authenticate with the service. The auth parameter allows you to specify the login method. Possible values are:

• session: Creates a Redfish session with a session token.
• basic: Uses HTTP Basic authentication for all requests.

REDFISH_OBJ.login(auth="session")

Perform a GET operation

A simple GET operation can be performed to obtain the data present in any valid path. An example of GET operation on the path "/redfish/v1/Systems/1" is shown below:

response = REDFISH_OBJ.get("/redfish/v1/Systems/1")

Perform a POST operation

A POST operation can be performed to create a resource or perform an action. An example of a POST operation on the path "/redfish/v1/Systems/1/Actions/ComputerSystem.Reset" is shown below:

body = {"ResetType": "GracefulShutdown"}
response = REDFISH_OBJ.post("/redfish/v1/Systems/1/Actions/ComputerSystem.Reset", body=body)

Notes about HTTP methods and arguments

The previous sections showed example GET and POST requests. The following is a list of the different methods supported:

• get: Performs an HTTP GET operation to retrieve a resource from a URI.
• head: Performs an HTTP HEAD operation to retrieve response headers from a URI, but no body.
• post: Performs an HTTP POST operation to perform an action or create a new resource.
• put: Performs an HTTP PUT operation to replace an existing resource.
• patch: Performs an HTTP PATCH operation to update an existing resource.
• delete: Performs an HTTP DELETE operation to remove a resource.

Each of the previous methods allows for the following arguments:

• path: Required. String. The URI in which to invoke the operation.
  • Example: "/redfish/v1/Systems/1"
• args: Dictionary. Query parameters to supply with the request.
  • The key-value pairs in the dictionary are the query parameter name and the query parameter value to supply.
  • Example: {"$select": "Reading,Status"}
• body: Dictionary, List, Bytes, or String. The request body to provide with the request.
  • Not supported for get, head, or delete methods.
  • The data type supplied will dictate the encoding.
  • A dictionary is the most common usage, which results in a JSON body.
  • Example: {"ResetType": "GracefulShutdown"}
  • A list is used to supply multipart forms, which is useful for multipart HTTP push updates.
  • Bytes is used to supply an octet stream.
  • A string is used to supply an unstructed body, which may be used in some OEM cases.
• headers: Dictionary. Additional HTTP headers to supply with the request.
  • The key-value pairs in the dictionary are the HTTP header name and the HTTP header value to supply.
  • Example: {"If-Match": etag_value}
• timeout: Number. The number of seconds to wait for a response before closing the connection for this request.
  • Overrides the timeout value specified when the Redfish object is created for this request.
  • This can be useful when a particular URI is known to take a long time to respond, such as with firmware updates.
  • The default value is None, which indicates the object-defined timeout is used.
• max_retry: Number. The number of retries to perform an operation before giving up for this request.
  • Overrides the max retry value specified when the Redfish object is created for this request.
  • This can be useful when a particular URI is known to take multiple retries.
  • The default value is None, which indicates the object-defined max retry count is used.

Working with tasks

POST, PATCH, PUT, and DELETE operations may result in a task, describing an operation with a duration greater than the span of a single request. The action message object that is_processing will return a task that can be accessed reviewed when polled with monitor. An example of a POST operation with a possible task is shown below.

body = {"ResetType": "GracefulShutdown"}
response = REDFISH_OBJ.post("/redfish/v1/Systems/1/Actions/ComputerSystem.Reset", body=body)
if(response.is_processing):
    task = response.monitor(REDFISH_OBJ)

    while(task.is_processing):
        retry_time = task.retry_after
        task_status = task.dict['TaskState']
        time.sleep(retry_time if retry_time else 5)
        task = response.monitor(REDFISH_OBJ)

Logout the created session

Ensure you perform a logout operation when done interacting with the Redfish service. If this step isn't performed, the session will remain active until the Redfish service decides to close it.

REDFISH_OBJ.logout()

The logout operation deletes the current sesssion from the service. The redfish_client object destructor includes a logout statement.

Using proxies

There are two methods for using proxies: configuring environment variables or directly providing proxy information.

Environment variables

You can use a proxy by specifying the HTTP_PROXY and HTTPS_PROXY environment variables. Hosts to be excluded from the proxy can be specified using the NO_PROXY environment variable.

export HTTP_PROXY="http://192.168.1.10:8888"
export HTTPS_PROXY="http://192.168.1.10:8888"

Directly provided

You can use a proxy by building a dictionary containing the proxy information and providing it to the proxies argument when creating the redfish_client object. The key-value pairs of the dictionary contain the protocol and the proxy URL for the protocol.

proxies = {
    'http': 'http://192.168.1.10:8888',
    'https': 'http://192.168.1.10:8888',
}
REDFISH_OBJ = redfish.redfish_client(base_url=login_host, username=login_account, \
                      password=login_password, proxies=proxies)

SOCKS proxy support

An additional package is required to use SOCKS proxies.

pip install -U requests[socks]

Once installed, the proxy can be configured using environment variables or directly provided like any other proxy. For example:

export HTTP_PROXY="socks5h://localhost:8123"
export HTTPS_PROXY="socks5h://localhost:8123"

Release Process

1. Go to the "Actions" page
2. Select the "Release and Publish" workflow
3. Click "Run workflow"
4. Fill out the form
5. Click "Run workflow"

Copyright and License

Copyright Notice: Copyright 2016-2022 DMTF. All rights reserved. License: BSD 3-Clause License. For full text see link: https://github.com/DMTF/python-redfish-library/blob/main/LICENSE.md