This guide will show you how to configure Flipt v2 to use branches for environments.

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Prerequisites

• Flipt v2
• A GitHub Account and a repository to sync to (Optional).

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Using Branches for Environments

Flipt v2 allows you to branch existing environments. This is useful if you want to test changes to your feature flags and configurations in a separate branch without affecting your users in production.

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Branch Storage

By default, environments and their branches are stored in memory. This means that if you restart Flipt, the data will be lost. You can configure Flipt to store your environments and branches in a Git repository on your local machine. See the Storage documentation for more information.

You can also configure Flipt to sync your environments and branches to a remote Git repository. This is useful if you want to share your environments and branches with your team or if you want to backup your data. See the Git Sync guide for more information.

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Creating a Branch

To create a branch simply click the branch button in the top right of the Flipt UI.

This will bring up a modal to allow you to enter the branch name.

Once you have entered the branch name, click the Create button. This will create a new branch with the same data as the source environment and update the UI to show the new branch.

As you can see, the new branch has the same data as the source environment however it is completely isolated from the source environment.

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Navigating With Branches

You can navigate between environments and branched environments by clicking the environment selector in the top left of the Flipt UI.

Branched environments are displayed as children of the source environment with a branch icon.

Clicking on a branched environment will switch to that environment. You can also select the namespace after selecting the environment.

See the concepts behind Environments and Namespaces for more information.

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Deleting a Branch

In a branched environment, you can see the source environment that the branch is based on in the top right of the Flipt UI.

Clicking the branch info will bring up a menu to allow you to delete the branch.

Type the branch name to confirm the deletion and click the Delete Branch button to delete the branch.

This will delete the branch and update the UI to show the source environment.

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Evaluation With Branches

Since branches are just environments themselves, you can evaluate within them just like you would evaluate any other environment using our UI, API or SDKs.

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In the UI

You can evaluate a flag in a branch by selecting the branch in the environment selector and then selecting the flag you want to evaluate.

Next click the View in Playground button to open the playground for that flag in the branched environment.

You can then evaluate the flag by entering an entity ID and context values.

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Using the API/SDKs

All of our SDKs support evaluating within environments and branches. See the SDKs documentation for more information.

In this example we’ll use the Go Client Side SDK to evaluate a flag in a branch.

Imagine that you have a branch called test and you want to evaluate a flag called test-flag in that branch. You can do the following:

client, err := flipt.NewClient(
    ctx,
    flipt.WithURL("http://localhost:8080"),
    flipt.WithEnvironment("test"),
  )
  if err != nil {
    log.Fatal(err)
  }
  defer client.Close(ctx)

  variantResult, _ := client.EvaluateVariant(ctx, &flipt.EvaluationRequest{
    FlagKey:  "test-flag",
    EntityID: "someentity",
    Context:  map[string]string{"fizz": "buzz"},
  })
  fmt.Println(variantResult)

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Using GitHub for Git Sync

If you’ve configured Flipt to use a GitHub repository for Git Sync, your branches will also be synced to your GitHub repository.

See the Git Sync guide for more information on how to configure Flipt to use a GitHub repository for Git Sync.

Any changes you make to a branch will be synced to your GitHub repository.

If you have Git Sync enabled, you’ll see a View Remote option in the branch info menu.

Clicking this will open the branch in your GitHub repository that is configured in your Flipt configuration file.