lekko_client 0.2.0rc1

Lekko Python SDK Client

Lekko Python SDK

The Lekko SDK for Python

Getting Started

Installation

pip install lekko_client

Usage

Initializing a cached Lekko client

Creates a client that fetches configs from Lekko backend and caches them in memory. Configs are kept up to date via polling.

import lekko_client

lekko_client.initialize(lekko_client.CachedServerConfig(
    owner_name="<REPOSITORY_OWNER>",
    repo_name="<REPOSITORY_NAME>",
    api_key="<API_KEY>",  # Optional - defaults to "LEKKO_API_KEY" ENV Var
    lekko_uri="<URI>",    # Optional - defaults to "prod.api.lekko.dev:443"
    context={},           # Optionally provide context dict to be merged into each get request
))

str_feature = lekko_client.get_string("my_namespace", "my_feature", {"context_key": "context_val"})

Initializing a cached Lekko client in git mode

Creates a client that reads configs from a git repository on disk and caches them in memory. Configs are kept up to date via a file watcher.

import lekko_client

lekko_client.initialize(lekko_client.CachedGitConfig(
    owner_name="<REPOSITORY_OWNER>",
    repo_name="<REPOSITORY_NAME>",
    git_repo_path="<GIT_REPO_PATH>",
    api_key="<API_KEY>",  # Optional - defaults to "LEKKO_API_KEY" ENV Var
    lekko_uri="<URI>",    # Optional - defaults to "prod.api.lekko.dev:443"
    context={},           # Optionally provide context dict to be merged into each get request
))

str_feature = lekko_client.get_string("my_namespace", "my_feature", {"context_key": "context_val"})

Initializing a Lekko client with a sidecar or server backend

Create a client that communicates with a Lekko Sidecar or the Lekko API backend

import lekko_client

lekko_client.initialize(lekko_client.APIConfig(  # Or lekko_client.SidcarConfig
    owner_name="<REPOSITORY_OWNER>",
    repo_name="<REPOSITORY_NAME>",
    api_key="<API_KEY>",  # Optional - defaults to "LEKKO_API_KEY" ENV Var
    context={},           # Optionally provide context dict to be merged into each get request
))

str_feature = lekko_client.get_string("my_namespace", "my_feature", {"context_key": "context_val"})

Lifecycle Management

lekko_client.initialize() must be invoked prior to calling the lekko_client.get_*() functions. We recommend invoking it early in your app's lifecycle, for example when constructing your Flask app or as part of FastAPI's lifecycle context manager.

We recommended you invoke lekko_client.close() during app shutdown. This will ensure all evaluation events are properly tracked and the distribution server is unregistered.

It is also possible to do your own lifecycle management and avoid the lekko_client.initialize() and lekko_client.get_*() methods entirely. Feel free to construct any of the clients in lekko_client.clients manually. This could make sense for the API or Sidecar clients, which have minimal state and startup costs. For example, it may be reasonable to do something like:

from lekko_client.clients import SidecarClient

SidecarClient(
    owner_name="<REPOSITORY_OWNER>",
    repo_name="<REPOSITORY_NAME>",
    api_key="<API_KEY>",
).get_string("my_namespace", "my_feature", {"context_key": "context_val"})

Proto Features

There are two methods to retrieve a Proto Feature, with one allowing you to specify the expected proto message type.

get_proto_by_type(key, context, proto_message_type) will attempt to convert the feature to the specified type and raise MismatchedProtoType on failure.

get_proto(key, context) will attempt to locate the proto message type in the proto symbol database, which tracks imported proto types. If unable to locate the type, it will simply return the message as a google.protobuf.any_pb2.Any

For example, if you have a proto feature named proto_feature defined as:

{
  "@type": "type.googleapis.com/google.protobuf.BoolValue",
  "value": false
}

You would see the following behavior:

>>> feature_value = client.get_proto("proto", {})
>>> type(feature_value)
<class 'google.protobuf.any_pb2.Any'>
>>> feature_value.value
b''

But after importing the appropriate type:

>>> from google.protobuf import wrappers_pb2
>>> feature_value = client.get_proto("proto", {})
>>> type(feature_value)
<class 'google.protobuf.wrappers_pb2.BoolValue'>
>>> feature_value.value
False

Example

See: https://github.com/lekkodev/python-sdk/blob/main/example.py