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Go

This category contains topics explaining how to configure Bucketeer's Go SDK.

Go SDK Version (Stable)

Bucketeer Go SDK has reached the production stage, offering you a stable and reliable experience.

Getting started​

Before starting, ensure that you follow the Getting Started guide.

Installing dependency​

Install the latest version of the client using the following command.

go get github.com/bucketeer-io/go-server-sdk

Importing SDK​

Import the Bucketeer SDK into your application code.

import (
	"github.com/bucketeer-io/go-server-sdk/pkg/bucketeer"
	"github.com/bucketeer-io/go-server-sdk/pkg/bucketeer/user"
)

Initializing client​

The SDK supports local and remote evaluations.

info

The tag setting is the tag you configure when creating a Feature Flag. It will evaluate all the Feature Flags in the environment when it is not configured.
We strongly recommend using tags to speed up the evaluation process and reduce the response latency.

Custom configuration​

Custom configuration

Depending on your use, you may want to change the optional configurations available.

  • eventQueueCapacity (Default is 100)
  • numEventFlushWorkers (Default is 50)
  • eventFlushInterval (Default is 1 minute)
  • eventFlushSize (Default is 100)
  • enableDebugLog (Default is false)
  • errorLogger (Default is log.DefaultErrorLogger)
  • enableLocalEvaluation (Default is false)
  • cachePollingInterval (Default is 1 minute)

For more information, please check the Option implementation here.

Remote evaluation​

To evaluate users on the server side you must create an API Key using the Client SDK role.

ctx, cancel := context.WithTimeout(context.Background(), timeout)
defer cancel()
client, err := bucketeer.NewSDK(
  ctx,
  bucketeer.WithAPIKey("YOUR_API_KEY"),
  bucketeer.WithHost("YOUR_API_ENDPOINT"),
  bucketeer.WithTag("YOUR_FEATURE_TAG"),
)
if err != nil {
  log.Fatalf("Failed initialize the new client: %v", err)
}

Once the SDK is configured, please check this section to learn how to get the variation for a user.

Evaluating users within SDK locally​

By evaluating users locally you can improve response time significantly.
To evaluate them you must create an API Key using the Server SDK role.

The SDK will poll the Feature Flags and Segment Users from the server, and cache them in memory.

caution

The Server SDK API Key has access to all Feature Flags and Segment Users in the environment.
Keep in mind that it might contain sensitive information, so be careful when sharing the key with others.

When initializing the SDK you must enable the local evaluation setting.

ctx, cancel := context.WithTimeout(context.Background(), timeout)
defer cancel()
client, err := bucketeer.NewSDK(
  ctx,
  bucketeer.WithAPIKey("YOUR_API_KEY"),
  bucketeer.WithHost("YOUR_API_ENDPOINT"),
  bucketeer.WithTag("YOUR_FEATURE_TAG"),
  bucketeer.WithEnableLocalEvaluation(true), // <--- Enable the local evaluation
  bucketeer.WithCachePollingInterval(10*time.Minute), // <--- Change the default interval if needed
)
if err != nil {
  log.Fatalf("Failed initialize the new client: %v", err)
}

Once the SDK is configured, please check this section to learn how to get the variation for a user.

Supported features​

Evaluating user​

The variation method determines whether or not a feature flag is enabled for a specific user.
To check which variation a specific user will receive, you can use the client like below.

user := user.NewUser(
  "END_USER_ID",
  nil, // The user attributes are optional
)
showNewFeature := client.BoolVariation(ctx, user, "YOUR_FEATURE_FLAG_ID", false)
if (showNewFeature) {
  // The Application code to show the new feature
} else {
  // The code to run when the feature is off
}
note

The variation method will return the default value if the feature flag doesn't exist, or is archived, or if the request fails.

Variation types​

The Bucketeer SDK supports the following variation types.

BoolVariation(ctx context.Context, user *user.User, featureID string, defaultValue bool) bool

IntVariation(ctx context.Context, user *user.User, featureID string, defaultValue int) int

Int64Variation(ctx context.Context, user *user.User, featureID string, defaultValue int64) int64

Float64Variation(ctx context.Context, user *user.User, featureID string, defaultValue float64) float64

StringVariation(ctx context.Context, user *user.User, featureID, defaultValue string) string

JSONVariation(ctx context.Context, user *user.User, featureID string, dst interface{})

Reporting custom events​

This method lets you save user actions in your application as events. You can connect these events to metrics in the experiments or in the kill switch (auto operation) on the console UI.

In addition, you can pass a number value to the goal event. These values will sum and show as
Value total on the experiments console UI. This is useful if you have a goal event for tracking how much a user spent on your application buying items, etc.

user := user.NewUser(
  "END_USER_ID",
  nil, // The user attributes are optional
)
client.Track(ctx, user, "YOUR_GOAL_ID")

// Reporting with value
client.TrackValue(ctx, user, "YOUR_GOAL_ID", 10.50)

User attributes configuration​

This feature will give you robust and granular control over what users can see on your application.
You can add rules using these attributes on the console UI's feature flag's targeting tab. See more.

attributes := make(map[string]string)
attributes["app_version"] = "1.0.0"
attributes["os_version"] = "11.0.0"
attributes["device_model"] = "pixel-5"
attributes["language"] = "english"
attributes["genre"] = "female"

user := user.NewUser(
  "END_USER_ID",
  attributes,
)
showNewFeature := client.BoolVariation(ctx, user, "YOUR_FEATURE_FLAG_ID", false)

Closing client​

This method will send all pending analytics events to the Bucketeer server as soon as possible and tear down all the SDK activities and resources.
The application should call this before the application stops. Otherwise, the remaining events can be lost.

if err := client.Close(ctx); err != nil {
	return fmt.Errorf("Failed to close the client: %v", err)
}