Welcome to pyetcd’s documentation!

Contents:

pyetcd

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Python library to work with Etcd.

Features

  • Basic key operations

Credits

This package was created with Cookiecutter and the audreyr/cookiecutter-pypackage project template.

Installation

Stable release

To install pyetcd, run this command in your terminal:

$ pip install pyetcd

This is the preferred method to install pyetcd, as it will always install the most recent stable release.

If you don’t have pip installed, this Python installation guide can guide you through the process.

From sources

The sources for pyetcd can be downloaded from the Github repo.

You can either clone the public repository:

$ git clone git://github.com/twindb/pyetcd

Or download the tarball:

$ curl  -OL https://github.com/twindb/pyetcd/tarball/master

Once you have a copy of the source, you can install it with:

$ python setup.py install

Usage

Connect to local etcd instance. Write a key and read it after:

from pyetcd.client import Client

client = Client()
client.write('/message', 'Hello world')
response = client.read('/message')

print(response.node['value'])

Write and read from a remote etcd cluster:

from pyetcd.client import Client

client = Client([
    '10.0.1.10',
    '10.0.1.11',
    '10.0.1.12'
])
client.write('/message', 'Hello world')
response = client.read('/message')

print(response.node['value'])

Watch a key:

from pyetcd.client import Client

client = Client([
    '10.0.1.10',
    '10.0.1.11',
    '10.0.1.12'
])
client.write('/message', 'Hello world')
response = client.read('/message', wait=True)

print(response.node['value'])

pyetcd

pyetcd package

Submodules

pyetcd.client module

module to connect to an etcd node and perform low rest API requests.

class pyetcd.client.Client(**kwargs)[source]

Bases: object

Etcd Client class.

Parameters:

kwargs

Keyword arguments:

  • host (str, list(str), list(tuple)) - etcd node hostname
    or list of hostnames or list of tuples (hostname, port). Default is ‘127.0.0.1’.
  • port (int) - TCP port to connect to. Default is 2379.
  • srv_domain (str) - Domain name if DNS discovery is used
  • version_prefix (str) - API version prefix. Default is ‘v2’.
  • allow_reconnect (bool) - If client fails to connect to
    a cluster node connect to the next node in the cluster. Default is True.
  • protocol (str) - Protocol to connect to the cluster.
    Default is ‘http’.

Raises:
  • ClientException – if any errors
  • NotImplementedError – if there is an attempt to use unsupported DNS discovery.
add_member(peer_urls)[source]

Add a node to the cluster.

Parameters:peer_urls

List of URL for inter-peer communication. For example:

["http://10.0.0.10:2380"]
Returns:Information about the newly added node.
Return type:EtcdResult
compare_and_delete(key, prev_value=None, prev_index=None)[source]

This command will delete a key only if the client-provided conditions are equal to the current conditions.

Parameters:
  • key – the key
  • prev_value – checks the previous value of the key.
  • prev_index – checks the previous modifiedIndex of the key.
Returns:

Result of operation.

Return type:

EtcdResult

Raises:
compare_and_swap(key, value, prev_value=None, prev_index=None, prev_exist=None, ttl=None)[source]

This command will set the value of a key only if the client-provided conditions are equal to the current conditions.

Parameters:
  • key – key string
  • value – key value
  • prev_value – checks the previous value of the key.
  • prev_index – checks the previous modifiedIndex of the key.
  • prev_exist – checks existence of the key: if prevExist is True, it is an update request; if prevExist is False, it is a create request.
  • ttl – set ttl on the key in seconds
Returns:

Result of operation.

Return type:

EtcdResult

Raises:
delete(key)[source]

Delete a key

Parameters:key – Key
Returns:Result of operation.
Return type:EtcdResult
Raises:EtcdException – if etcd responds with error or HTTP error
health
Returns:True if the node is healthy
Return type:bool
mkdir(directory)[source]

Create directory

Parameters:directory – string with directory name
Returns:Result of operation.
Return type:EtcdResult
Raises:EtcdException – if etcd responds with error or HTTP error
read(key, **kwargs)[source]

Read key value

Parameters:key – Key
Returns:Result of operation.
Return type:EtcdResult
Raises:EtcdException – if etcd responds with error or HTTP error
remove_member(member_id)[source]

Remove a node from the cluster.

Parameters:member_id – etcd identifier of the node. For example, 272e204152.
rmdir(directory, recursive=False)[source]

Delete directory

Parameters:
  • directory – string with directory name
  • recursive – recursively delete directory if not empty
Returns:

Result of operation.

Return type:

EtcdResult

Raises:

EtcdException – if etcd responds with error or HTTP error

update_ttl(key, ttl)[source]

Update key’s ttl

Parameters:
  • key – the key
  • ttl – new ttl
Returns:

Result of operation.

Return type:

EtcdResult

Raises:
version()[source]

Return Etcd server version

Returns:string with Etcd server version. E.g. ‘2.3.7’
Return type:str
version_cluster()[source]

Return Etcd cluster version

Returns:string with Etcd cluster version. E.g. ‘2.3.0’
Return type:str
version_server()[source]

Same as .version()

Returns:string with Etcd server version. E.g. ‘2.3.7’
Return type:str
write(key, value, ttl=None)[source]

Write value to a key

Parameters:
  • key – Key
  • value – Value
  • ttl – Keys in etcd can be set to expire after a specified number of seconds. You can do this by setting a TTL (time to live) on the key.
Returns:

Result of operation.

Return type:

EtcdResult

Raises:

EtcdException – if etcd responds with error or HTTP error

exception pyetcd.client.ClientException[source]

Bases: exceptions.Exception

Exception for errors in Client class

Module contents

pyetcd is a module to work with etcd cluster

exception pyetcd.EtcdClientInternal[source]

Bases: pyetcd.EtcdException

Error ecodeClientInternal (http code 500)

exception pyetcd.EtcdDirNotEmpty[source]

Bases: pyetcd.EtcdException

Error EcodeDirNotEmpty (http code 108)

exception pyetcd.EtcdEmptyResponse[source]

Bases: pyetcd.EtcdInvalidResponse

Error that raises if response from etcd is empty

exception pyetcd.EtcdEventIndexCleared[source]

Bases: pyetcd.EtcdException

Error EcodeEventIndexCleared (http code 401)

exception pyetcd.EtcdException[source]

Bases: exceptions.Exception

Generic Etcd error.

exception pyetcd.EtcdExistingPeerAddr[source]

Bases: pyetcd.EtcdException

Error ecodeExistingPeerAddr (http code 109)

exception pyetcd.EtcdIndexNaN[source]

Bases: pyetcd.EtcdException

Error EcodeIndexNaN (http code 203)

exception pyetcd.EtcdIndexOrValueRequired[source]

Bases: pyetcd.EtcdException

Error ecodeIndexOrValueRequired (http code 207)

exception pyetcd.EtcdIndexValueMutex[source]

Bases: pyetcd.EtcdException

Error ecodeIndexValueMutex (http code 208)

exception pyetcd.EtcdInvalidActiveSize[source]

Bases: pyetcd.EtcdException

Error ecodeInvalidActiveSize (http code 403)

exception pyetcd.EtcdInvalidField[source]

Bases: pyetcd.EtcdException

Error EcodeInvalidField (http code 209)

exception pyetcd.EtcdInvalidForm[source]

Bases: pyetcd.EtcdException

Error EcodeInvalidForm (http code 210)

exception pyetcd.EtcdInvalidRemoveDelay[source]

Bases: pyetcd.EtcdException

Error ecodeInvalidRemoveDelay (http code 404)

exception pyetcd.EtcdInvalidResponse[source]

Bases: pyetcd.EtcdException

Error that raises if response from etcd is invalid

exception pyetcd.EtcdKeyIsPreserved[source]

Bases: pyetcd.EtcdException

Error ecodeKeyIsPreserved (http code 106)

exception pyetcd.EtcdKeyNotFound[source]

Bases: pyetcd.EtcdException

Error EcodeKeyNotFound (http code 100)

exception pyetcd.EtcdLeaderElect[source]

Bases: pyetcd.EtcdException

Error EcodeLeaderElect (http code 301)

exception pyetcd.EtcdNameRequired[source]

Bases: pyetcd.EtcdException

Error ecodeNameRequired (http code 206)

exception pyetcd.EtcdNoMorePeer[source]

Bases: pyetcd.EtcdException

Error ecodeNoMorePeer (http code 103)

exception pyetcd.EtcdNodeExist[source]

Bases: pyetcd.EtcdException

Error EcodeNodeExist (http code 105)

exception pyetcd.EtcdNotDir[source]

Bases: pyetcd.EtcdException

Error EcodeNotDir (http code 104)

exception pyetcd.EtcdNotFile[source]

Bases: pyetcd.EtcdException

Error EcodeNotFile (http code 102)

exception pyetcd.EtcdPrevValueRequired[source]

Bases: pyetcd.EtcdException

Error EcodePrevValueRequired (http code 201)

exception pyetcd.EtcdRaftInternal[source]

Bases: pyetcd.EtcdException

Error EcodeRaftInternal (http code 300)

exception pyetcd.EtcdRefreshTTLRequired[source]

Bases: pyetcd.EtcdException

Error EcodeRefreshTTLRequired (http code 212)

exception pyetcd.EtcdRefreshValue[source]

Bases: pyetcd.EtcdException

Error EcodeRefreshValue (http code 211)

class pyetcd.EtcdResult(response)[source]

Bases: object

Response from Etcd API.

Parameters:

response (requests.Response) – Response from server as requests.(get|post|put) returns.

Raises:
action

Action type

followers

Followers of leader

health

name

id

etcd identifier of the etcd node.

leader

Leader of cluster

leaderInfo
name

etcd name of the node.

node

Node class instance. It holds the current key value.

prevNode

Node class instance. It holds the previous key value.

recvAppendRequestCnt
sendAppendRequestCnt
startTime
state
version_etcdcluster

Version of Etcd cluster

version_etcdserver

Version of Etcd server

x_etcd_index

current etcd index that represents key modification version.

exception pyetcd.EtcdRootROnly[source]

Bases: pyetcd.EtcdException

Error EcodeRootROnly (http code 107)

exception pyetcd.EtcdStandbyInternal[source]

Bases: pyetcd.EtcdException

Error ecodeStandbyInternal (http code 402)

exception pyetcd.EtcdTTLNaN[source]

Bases: pyetcd.EtcdException

Error EcodeTTLNaN (http code 202)

exception pyetcd.EtcdTestFailed[source]

Bases: pyetcd.EtcdException

Error EcodeTestFailed (http code 101)

exception pyetcd.EtcdTimeoutNaN[source]

Bases: pyetcd.EtcdException

Error ecodeTimeoutNaN (http code 205)

exception pyetcd.EtcdUnauthorized[source]

Bases: pyetcd.EtcdException

Error EcodeUnauthorized (http code 110)

exception pyetcd.EtcdValueOrTTLRequired[source]

Bases: pyetcd.EtcdException

Error ecodeValueOrTTLRequired (http code 204)

exception pyetcd.EtcdValueRequired[source]

Bases: pyetcd.EtcdException

Error ecodeValueRequired (http code 200)

exception pyetcd.EtcdWatcherCleared[source]

Bases: pyetcd.EtcdException

Error EcodeWatcherCleared (http code 400)

Contributing

Contributions are welcome, and they are greatly appreciated! Every little bit helps, and credit will always be given.

You can contribute in many ways:

Types of Contributions

Report Bugs

Report bugs at https://github.com/twindb/pyetcd/issues.

If you are reporting a bug, please include:

  • Your operating system name and version.
  • Any details about your local setup that might be helpful in troubleshooting.
  • Detailed steps to reproduce the bug.

Fix Bugs

Look through the GitHub issues for bugs. Anything tagged with “bug” and “help wanted” is open to whoever wants to implement it.

Implement Features

Look through the GitHub issues for features. Anything tagged with “enhancement” and “help wanted” is open to whoever wants to implement it.

Write Documentation

pyetcd could always use more documentation, whether as part of the official pyetcd docs, in docstrings, or even on the web in blog posts, articles, and such.

Submit Feedback

The best way to send feedback is to file an issue at https://github.com/twindb/pyetcd/issues.

If you are proposing a feature:

  • Explain in detail how it would work.
  • Keep the scope as narrow as possible, to make it easier to implement.
  • Remember that this is a volunteer-driven project, and that contributions are welcome :)

Get Started!

Ready to contribute? Here’s how to set up pyetcd for local development.

  1. Fork the pyetcd repo on GitHub.

  2. Clone your fork locally:

    $ git clone git@github.com:your_name_here/pyetcd.git
    
  3. Install your local copy into a virtualenv. Assuming you have virtualenvwrapper installed, this is how you set up your fork for local development:

    $ mkvirtualenv pyetcd
    $ cd pyetcd/
    $ python setup.py develop
    
  4. Create a branch for local development:

    $ git checkout -b name-of-your-bugfix-or-feature
    

    Now you can make your changes locally.

  5. When you’re done making changes, check that your changes pass flake8 and the tests, including testing other Python versions with tox:

    $ flake8 pyetcd tests
    $ python setup.py test or py.test
    $ tox
    

    To get flake8 and tox, just pip install them into your virtualenv.

  6. Commit your changes and push your branch to GitHub:

    $ git add .
    $ git commit -m "Your detailed description of your changes."
    $ git push origin name-of-your-bugfix-or-feature
    
  7. Submit a pull request through the GitHub website.

Pull Request Guidelines

Before you submit a pull request, check that it meets these guidelines:

  1. The pull request should include tests.
  2. If the pull request adds functionality, the docs should be updated. Put your new functionality into a function with a docstring, and add the feature to the list in README.rst.
  3. The pull request should work for Python 2.6, 2.7, 3.4 and 3.5, and for PyPy. Check https://travis-ci.org/twindb/pyetcd/pull_requests and make sure that the tests pass for all supported Python versions.

Tips

To run a subset of tests:

$ py.test tests/test_client.py
$ py.test tests/test_etcdresult.py

To run individual tests:

$ py.test tests/test_client.py::test_write

Credits

Development Lead

Contributors

None yet. Why not be the first?

History

0.1.0 (2016-09-17)

  • First release on PyPI.

Indices and tables