LaunchDarkly Server-side SDK for Go - Consul integration

This library provides a Consul-backed persistence mechanism (data store) for the LaunchDarkly Go SDK, replacing the default in-memory data store. It uses the standard Consul Go client.

This version of the library requires at least version 6.0.0 of the LaunchDarkly Go SDK; for versions of the library to use with earlier SDK versions, see the changelog.

The minimum Go version is 1.18.

For more information, see also: Using Consul as a persistent feature store.

Quick setup

This assumes that you have already installed the LaunchDarkly Go SDK.

1. Import the LaunchDarkly SDK packages and the package for this library:

import (
    ld "github.com/launchdarkly/go-server-sdk/v7"
    "github.com/launchdarkly/go-server-sdk/v7/ldcomponents"
    ldconsul "github.com/launchdarkly/go-server-sdk-consul/v3"
)

2. When configuring your SDK client, add the Consul data store as a PersistentDataStore. You may specify any custom Consul options using the methods of ConsulDataStoreBuilder. For instance, to customize the Consul hostname:

    var config ld.Config{}
    config.DataStore = ldcomponents.PersistentDataStore(
        ldconsul.DataStore().Address("my-consul-host"),
    )

By default, the store will try to connect to a local Consul instance on port 8500.

Caching behavior

The LaunchDarkly SDK has a standard caching mechanism for any persistent data store, to reduce database traffic. This is configured through the SDK's PersistentDataStoreBuilder class as described the SDK documentation. For instance, to specify a cache TTL of 5 minutes:

    var config ld.Config{}
    config.DataStore = ldcomponents.PersistentDataStore(
        ldconsul.DataStore(),
    ).CacheMinutes(5)

Data size limitation

Consul does not support storing values greater than 512KB. Therefore, this integration will not work if the JSON representation of any feature flag or user segment exceeds that size.

To see the JSON representations of all flags and segments, query https://app.launchdarkly.com/sdk/latest-all with your SDK key in an Authorization header.

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