Kinto python client
Kinto is a service that allows users to store and synchronize arbitrary data, attached to a user account. Its primary interface is HTTP.
kinto-http is a Python library that eases the interactions with a Kinto server instance. A project with related goals is also available for JavaScript.
Installation
Use pip:
$ pip install kinto-http
Usage
Note
Operations are always performed directly on the server, and no synchronisation features have been implemented yet.
- The first version of this API doesn't cache any access nor provides any refresh mechanism. If you want to be sure you have the latest data available, issue another call.
Here is an overview of what the API provides:
from kinto_http import Client
client = 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 #%d' %i
for record in records:
client.update_record(record)
Creating a client
The passed auth parameter is a requests authentication policy, allowing authenticating using whatever scheme fits you best.
By default, Kinto supports Firefox Accounts and Basic authentication policies.
from kinto_http import Client
credentials = ('alexis', 'p4ssw0rd')
client = Client(server_url='http://localhost:8888/v1',
auth=credentials)
It is also possible to pass the bucket and the collection to the client at creation time, so that this value will be used by default.
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")
Getting server information
You can use the server_info
method to get 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."
Handling buckets
All operations are rooted in a bucket. It makes little sense for one application to handle multiple buckets at once (but it is possible). If no specific bucket name is provided, the "default" bucket is used.
from kinto_http import Client
credentials = ('alexis', 'p4ssw0rd')
client = Client(server_url='http://localhost:8888/v1',
auth=credentials)
# To create a bucket.
client.create_bucket('payments')
# To get an existing bucket
bucket = client.get_bucket('payments')
# Or retrieve all readable buckets.
buckets = client.get_buckets()
# To create or replace an existing bucket.
client.update_bucket('payments', data={'description': 'My payments data.'})
# Or modify some fields in an existing bucket.
client.patch_bucket('payments', data={'status': 'updated'})
# It is also possible to manipulate bucket permissions (see later)
client.patch_bucket('payments', permissions={})
# Or delete a bucket and everything under.
client.delete_bucket('payment')
# Or even every writable buckets.
client.delete_buckets()
Groups
A group associates a name to a list of principals. It is useful in order to handle permissions.
# To create a group.
client.create_group('receipts', bucket='payments', data={'members': ['blah', 'foo']})
# Or get an existing one.
group = client.get_group('receipts', bucket='payments')
# Or retrieve all groups in the bucket.
groups = client.get_groups(bucket='payments')
# To create or replace an existing bucket.
client.update_group('receipts', bucket='payments', data={'members': ['foo']})
# Or modify some fields in an existing group.
client.patch_group('receipts', bucket='payments', data={'description': 'my group'})
# To delete an existing group.
client.delete_group('receipts', bucket='payments')
# Or all groups in a bucket.
client.delete_groups(bucket='payments')
Collections
A collection is where records are stored.
# To create a collection.
client.create_collection('receipts', bucket='payments')
# Or get an existing one.
collection = client.get_collection('receipts', bucket='payments')
# Or retrieve all of them inside a bucket.
collections = client.get_collections(bucket='payments')
# To create or replace an exiting collection.
client.update_collection(bucket='payments', data={'description':'bleeh'})
# Or modify some fields of an existing collection.
client.patch_collection(bucket='payments', data={'status':'updated'})
# To delete an existing collection.
client.delete_collection('receipts', bucket='payments')
# Or every collections in a bucket.
client.delete_collections(bucket='payments')
Records
Records can be retrieved from and saved to collections.
A record is a dict with the "permissions" and "data" keys.
# You can pass a python dictionary to create the record.
client.create_record(data={'status': 'done', title: 'Todo #1'},
collection='todos', bucket='default')
# You can use id to specify the record id when creating it.
client.create_record(id='todo2', data={'status': 'doing', 'title': 'Todo #2'},
collection='todos', bucket='default')
# Or get an existing one by its id.
record = client.get_record('todo2', collection='todos', bucket='default')
# Or retrieve all records.
records = client.get_records(collection='todos', bucket='default')
# Or retrieve records timestamp.
records_timestamp = client.get_records_timestamp(collection='todos', bucket='default')
# To replace a record using a previously fetched record
client.update_record(record, collection='todos', bucket='default')
# Or create or replace it by its id.
client.update_record({'status': 'unknown'}, id='todo2', collection='todos', bucket='default')
# Or modify some fields in an existing record.
client.patch_record({'assignee': 'bob'}, id='todo2', collection='todos', bucket='default')
# Or update multiple records at once.
client.update_records(records, collection='todos')
# To delete an existing record.
client.delete_record(id='89881454-e4e9-4ef0-99a9-404d95900352',
collection='todos')
# Or every records of a collection.
client.delete_records(collection='todos')
Permissions
By default, authors will get read and write access to the manipulated objects. It is possible to change this behavior by passing a dict to the permissions parameter.
client.create_record( data={'foo': 'bar'}, permissions={'read': ['group:groupid']}, collection='todos')
Note
Every creation or modification operation on a distant object can be given a permissions parameter.
Buckets, collections and records have permissions which can be edited. For instance to give access to "leplatrem" to a specific record, you would do:
record = client.get_record(1234, collection='todos', bucket='alexis')
record['permissions']['write'].append('leplatrem')
client.update_record(record)
# During creation, it is possible to pass the permissions dict.
client.create_record(data={'foo': 'bar'}, permissions={})
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('bucket', if_not_exists=True)
Delete
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('bucket', if_exists=True)
Overwriting existing objects
Most of the methods take a safe
argument, which defaults to True
. If set
to True
and a last_modified
field is present in the passed data
,
or if the if_match
parameter is specified then a
check will be added to the requests to ensure the record wasn't modified on
the server side in the meantime.
Batching operations
Rather than issuing a request for each and every operation, it is possible to batch the requests. The client will then issue as little requests as possible.
Currently, batching operations only supports write operations, so it is not possible to do the retrieval of information inside a batch.
It is possible to do batch requests using a Python context manager (with
):
with client.batch() as batch:
for idx in range(0,100):
batch.update_record(data={'id': idx})
A batch object shares the same methods as another client.
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)
Generating endpoint paths
You may want to generate some endpoint paths, you can use the get_endpoint utility to do so:
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'
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("%s records." % 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 token:my-secret -b BUCKET, --bucket BUCKET Bucket name. -c COLLECTION, --collection COLLECTION Collection name. -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