kinto-http 10.5.0

Kinto client

kinto-http is the Python library to interact with a Kinto server.

There is also a similar client in JavaScript.

Installation

Use pip:

$ pip install kinto-http

Usage

Here is an overview of what the API provides:

import kinto_http

client = kinto_http.Client(server_url="http://localhost:8888/v1",
                           auth=('alexis', 'p4ssw0rd'))

records = client.get_records(bucket='default', collection='todos')
for i, record in enumerate(records):
    record['title'] = 'Todo {}'.format(i)
    client.update_record(data=record)

Instantiating a client

The passed auth parameter is a requests authentication policy.

By default, a simple tuple will become a Basic Auth authorization request header, that can authenticate users with Kinto Accounts.

import kinto_http

auth = ('alexis', 'p4ssw0rd')

client = kinto_http.Client(server_url='http://localhost:8888/v1',
                           auth=auth)

It is also possible to pass a bucket ID and/or collection ID to set them as default values for the parameters of the client operations.

client = Client(bucket="payments", collection="receipts", auth=auth)

After creating a client, you can also replicate an existing one and overwrite some key arguments.

client2 = client.clone(collection="orders")

Using a Bearer access token to authenticate (OpenID)

import kinto_http

client = kinto_http.Client(auth=kinto_http.BearerTokenAuth("XYPJTNsFKV2"))

The authorization header is prefixed with Bearer by default. If the header_type is customized on the server, the client must specify the expected type: kinto_http.BearerTokenAuth("XYPJTNsFKV2" type="Bearer+OIDC")

Getting server information

You can use the server_info() method to fetch the server information:

from kinto_http import Client

client = Client(server_url='http://localhost:8888/v1')
info = client.server_info()
assert 'schema' in info['capabilities'], "Server doesn't support schema validation."

Bucket operations

• get_bucket(id=None, **kwargs): retrieve single bucket
• get_buckets(**kwargs): retrieve all readable buckets
• create_bucket(id=None, data=None, **kwargs): create a bucket
• update_bucket(id=None, data=None, **kwargs): create or replace an existing bucket
• patch_bucket(id=None, changes=None, **kwargs): modify some fields in an existing bucket
• delete_bucket(id=None, **kwargs): delete a bucket and everything under it
• delete_buckets(**kwargs): delete every writable buckets

Groups operations

• get_group(id=None, bucket=None, **kwargs): retrieve single group
• get_groups(bucket=None, **kwargs): retrieve all readable groups
• create_group(id=None, data=None, bucket=None, **kwargs): create a group
• update_group(id=None, data=None, bucket=None, **kwargs): create or replace an existing group
• patch_group(id=None, changes=None, bucket=None, **kwargs): modify some fields in an existing group
• delete_group(id=None, bucket=None, **kwargs): delete a group and everything under it
• delete_groups(bucket=None, **kwargs): delete every writable groups

Collections

• get_collection(id=None, bucket=None, **kwargs): retrieve single collection
• get_collections(bucket=None, **kwargs): retrieve all readable collections
• create_collection(id=None, data=None, bucket=None, **kwargs): create a collection
• update_collection(id=None, data=None, bucket=None, **kwargs): create or replace an existing collection
• patch_collection(id=None, changes=None, bucket=None, **kwargs): modify some fields in an existing collection
• delete_collection(id=None, bucket=None, **kwargs): delete a collection and everything under it
• delete_collections(bucket=None, **kwargs): delete every writable collections

Records

• get_record(id=None, bucket=None, collection=None, **kwargs): retrieve single record
• get_records(bucket=None, collection=None, **kwargs): retrieve all readable records
• get_paginated_records(bucket=None, collection=None, **kwargs): paginated list of records
• get_records_timestamp(bucket=None, collection=None, **kwargs): return the records timestamp of this collection
• create_record(id=None, data=None, bucket=None, collection=None, **kwargs): create a record
• update_record(id=None, data=None, bucket=None, collection=None, **kwargs): create or replace an existing record
• patch_record(id=None, changes=None, bucket=None, collection=None, **kwargs): modify some fields in an existing record
• delete_record(id=None, bucket=None, collection=None, **kwargs): delete a record and everything under it
• delete_records(bucket=None, collection=None, **kwargs): delete every writable records

Permissions

The objects permissions can be specified or modified by passing a permissions to create_*(), patch_*(), or update_*() methods:

client.create_record(data={'foo': 'bar'},
                     permissions={'read': ['group:groupid']})


record = client.get_record('123', collection='todos', bucket='alexis')
record['permissions']['write'].append('leplatrem')
client.update_record(data=record)

Get or create

In some cases, you might want to create a bucket, collection, group or record only if it doesn’t exist already. To do so, you can pass the if_not_exists=True to the create_*() methods:

client.create_bucket(id='blog', if_not_exists=True)
client.create_collection(id='articles', bucket='blog', if_not_exists=True)

Delete if exists

In some cases, you might want to delete a bucket, collection, group or record only if it exists already. To do so, you can pass the if_exists=True to the delete_* methods:

client.delete_bucket(id='bucket', if_exists=True)

Patch operations

The .patch_*() operations receive a changes parameter.

from kinto_http.patch_type import BasicPatch, MergePatch, JSONPatch


client.patch_record(id='abc', changes=BasicPatch({'over': 'write'}))

client.patch_record(id='todo', changes=MergePatch({'assignee': 'bob'}))

client.patch_record(id='receipts', changes=JSONPatch([
    {'op': 'add', 'path': '/data/members/0', 'value': 'ldap:[e-mail]'}
]))

Concurrency control

The create_*(), patch_*(), and update_*() methods take a safe argument (default: True).

If True, the client will ensure that the object wasn’t modified on the server side since we fetched it. The timestamp will be implicitly read from the last_modified field in the passed data object, or taken explicitly from the if_match parameter.

Batching operations

Rather than issuing a request for each and every operation, it is possible to batch several operations in one request.

Using the batch() method as a Python context manager (with):

with client.batch() as batch:
    for idx in range(0, 100):
        batch.update_record(data={'id': idx})

Note

Besides the results() method, a batch object shares all the same methods as another client.

Reading data from batch operations is achieved by using the results() method available after a batch context is closed.

with client.batch() as batch:
    batch.get_record('r1')
    batch.get_record('r2')
    batch.get_record('r3')

r1, r2, r3 = batch.results()

Errors

Failing operations will raise a KintoException, which has request and response attributes.

try:
    client.create_group(id="friends")
except kinto_http.KintoException as e:
    if e.response and e.response.status_code == 403:
        print("Not allowed!")

Retry on error

When the server is throttled (under heavy load or maintenance) it can return error responses.

The client can hence retry to send the same request until it succeeds. To enable this, specify the number of retries on the client:

client = Client(server_url='http://localhost:8888/v1',
                auth=credentials,
                retry=10)

The Kinto protocol lets the server define the duration in seconds between retries. It is possible (but not recommended) to force this value in the clients:

client = Client(server_url='http://localhost:8888/v1',
                auth=credentials,
                retry=10,
                retry_after=5)

Pagination

When the server responses are paginated, the client will download every page and merge them transparently.

The get_paginated_records() method returns a generator that will yield each page:

for page in client.get_paginated_records():
    records = page["data"]

It is possible to specify a limit for the number of items to be retrieved in one page:

records = client.get_records(_limit=10)

In order to retrieve every available pages with a limited number of items in each of them, you can specify the number of pages:

records = client.get_records(_limit=10, pages=float('inf'))  # Infinity

History

If the built-in history plugin is enabled, it is possible to retrieve the history of changes:

# Get the complete history of a bucket
changes = client.get_history(bucket='default')

# and optionally use filters
hist = client.get_history(bucket='default', _limit=2, _sort='-last_modified', _since='1533762576015')
hist = client.get_history(bucket='default', resource_name='collection')

The history of a bucket can also be purged with:

client.purge_history(bucket='default')

Endpoint URLs

The get_endpoint() method returns an endpoint URL on the server:

client = Client(server_url='http://localhost:8888/v1',
                auth=('token', 'your-token'),
                bucket="payments",
                collection="receipts")

print(client.get_endpoint("record",
                          id="c6894b2c-1856-11e6-9415-3c970ede22b0"))

# '/buckets/payments/collections/receipts/records/c6894b2c-1856-11e6-9415-3c970ede22b0'

Handling datetime and date objects

In addition to the data types supported by JSON, kinto-http.py also supports native Python date and datetime objects.

In case a payload contain a date or a datetime object, kinto-http.py will encode it as an ISO formatted string.

Please note that this transformation is only one-way. While reading a record, if a string contains a ISO formated string, kinto-http.py will not convert it to a native Python date or datetime object.

If you know that a field will be a datetime, you might consider encoding it yourself to be more explicit about it being a string for Kinto.

Command-line scripts

In order to have common arguments and options for scripts, some utilities are provided to ease configuration and initialization of client from command-line arguments.

import argparse
import logging

from kinto_http import cli_utils

logger = logging.getLogger(__name__)

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Download records")
    cli_utils.set_parser_server_options(parser)

    args = parser.parse_args()

    cli_utils.setup_logger(logger, args)

    logger.debug("Instantiate Kinto client.")
    client = cli_utils.create_client_from_args(args)

    logger.info("Fetch records.")
    records = client.get_records()
    logger.warn("{} records.".format(len(records)))

The script now accepts basic options:

$ python example.py --help

usage: example.py [-h] [-s SERVER] [-a AUTH] [-b BUCKET] [-c COLLECTION] [-v]
                  [-q] [-D]

Download records

optional arguments:
  -h, --help            show this help message and exit
  -s SERVER, --server SERVER
                        The location of the remote server (with prefix)
  -a AUTH, --auth AUTH  BasicAuth credentials: `token:my-secret` or
                        Authorization header: `Bearer token`
  -b BUCKET, --bucket BUCKET
                        Bucket name.
  -c COLLECTION, --collection COLLECTION
                        Collection name.
  --retry RETRY         Number of retries when a request fails
  --retry-after RETRY_AFTER
                        Delay in seconds between retries when requests fail
                        (default: provided by server)
  -v, --verbose         Show all messages.
  -q, --quiet           Show only critical errors.
  -D, --debug           Show all messages, including debug messages.

Run tests

In one terminal, run a Kinto server:

$ make runkinto

In another, run the tests against it:

$ make tests

(Optional) Install a git hook:

therapist install