immudb Blog Posts

immudb-py-get-started - immudb

Written by dennis | Sep 22, 2020 9:41:13 PM

First steps to use Python SDK for immudb — the blazing fast, open source immutable database

Contents

Introduction

immu-py implements a grpc immudb client. A minimalist API is exposed for applications while cryptographic
verifications and state update protocol implementation are fully implemented by this client.
Latest validated immudb state may be kept in the local filesystem when using default rootService,
please read immudb research paper for details of how immutability is ensured by immudb.

Prerequisites

immu-py assumes there is an existing instance of the immudb server up and running. Running immudb is quite simple, please refer to the
following link for downloading and running it: https://immudb.io/docs/quickstart.html

Installation

Install the package using pip:

    pip install git+https://github.com/codenotary/immu-py.git

Then import the client as follows:

    from immudb.client import ImmudbClient

Note: immu-py is currently hosted in [Github Packages].

Supported Versions

immu-py supports the latest immudb release.

Quickstart

Hello Immutable World! example can be found in immudb-client-examples repo.

Step by step guide

Creating a Client

The following code snippets shows how to create a client.

Using default configuration:

    client = ImmudbClient()

Setting immudb url and port:


    client = ImmudbClient("mycustomurl:someport")
    client = ImmudbClient("10.105.20.32:8899")

User sessions

Use login and logout methods to initiate and terminate user sessions:

    client.login("usr1", "pwd1");

    // Interact with immudb using logged user

    client.logout();

Encoding

Please note that, in order to provide maximum flexibility, all functions accept byte arrays as parameters. Therefore, unicode strings must be properly encoded.
It is possible to store structured objects, but they must be serialized (e.g., with pickle or json).

Creating a database

Creating a new database is quite simple:

    client.createDatabase(b"db1");

Setting the active database

Specify the active database with:

    client.useDatabase(b"db1");

If not specified, the default databased used is "defaultdb".

Traditional read and write

immudb provides read and write operations that behave as a traditional
key-value store i.e. no cryptographic verification is done. This operations
may be used when validations can be post-poned:

    client.set(b"k123", b"value123");
    result = client.get(b"k123");

Verified or Safe read and write

immudb provides built-in cryptographic verification for any entry. The client
implements the mathematical validations while the application uses as a traditional
read or write operation:

    try:
        client.safeSet(b"k123", new byte[]{1, 2, 3});
        results = client.safeGet(b"k123");
    Except VerificationException as e:
        # Do something

Multi-key read and write

Transactional multi-key read and write operations are supported by immudb and immupy.
Atomic multi-key write (all entries are persisted or none):

    normal_dictionary = {b"key1": b"value1", b"key2": b"value2"}
    client.setAll(normal_dictionary);

Atomic multi-key read (all entries are retrieved or none):

    normal_dictionary = {b"key1": b"value1", b"key2": b"value2"}
    results_dictionary = client.getAll(normal_dictionary.keys())
    # Or manually
    client.get([b"key1", b"key2"])

User management

Users can be added and granted access to databases.

Adding a user

The createUser functions create a new users and grants the specified permission to a database.

user='newuser'
password='Pw1:pasdfoiu'
permission=immudb.constants.PERMISSION_RW
database='defaultdb'

client.createUser(user, password, permission, database)

The database must exists at the time the user is created. The password must be between 8 and 32 characters in length, and must have at least one upper case letter, a symbol and a digit.

Permission are defined in immudb.constants and are:

  • PERMISSION_SYS_ADMIN
  • PERMISSION_ADMIN
  • PERMISSION_NONE
  • PERMISSION_R
  • PERMISSION_RW

Changing password

The user must must provide both old and new password:

newPassword="pW1:a0s98d7gfy"
resp=client.changePassword(user, newPassword, oldPassword)

It is applied the same password policy of user creation.

User list

To get the list of user created on immudb, simply call listUsers:

resp=client.listUsers()
print(users.userlist.users)

Closing the client

To programatically close the connection with immudb server use the shutdown operation:

    client.shutdown();

Note: after shutdown, a new client needs to be created to establish a new connection.

Contributing

We welcome contributions. Feel free to join the team!

To report bugs or get help, use GitHub’s issues.