Recently, we redesign the mini program project. During the iteration, some features should be on the beta version or the beta users. And we control these via rollout.

The rollout gem is the fast feature flags based on Redis.

Within rollout, you can set the feature flags on so many dimensions. Like the follows:

Set for groups

Rollout ships with one group by default: “all”, which does exactly what it sounds like.

You can activate the all group for the chat feature like this:

$rollout.activate_group(:chat, :all)

Deactivate groups like this:

$rollout.deactivate_group(:chat, :all)

Set for specific users

You might want to let a specific user into a beta test or something.

$rollout.activate_user(:chat, @user)

Deactivate them like this:

$rollout.deactivate_user(:chat, @user)

Set for user percentages

f you’re rolling out a new feature, you might want to test the waters by slowly enabling it for a percentage of your users.

$rollout.activate_percentage(:chat, 20)

The algorithm for determining which users get let in is this:

CRC32(user.id) < (2**32 - 1) / 100.0 * percentage

So, for 20%, users 0, 1, 10, 11, 20, 21, etc would be allowed in. Those users would remain in as the percentage increases.

Deactivate all percentages like this:

$rollout.deactivate_percentage(:chat)

Set for global actions

While groups can come in handy, the actual global setter for a feature does not require a group to be passed.

$rollout.activate(:chat)

In that case you can check the global availability of a feature using the following

$rollout.active?(:chat)

And if something is wrong you can set a feature off for everybody using

Deactivate everybody at once:

$rollout.deactivate(:chat)

END

You can replace the user object with other entity if you need.

$rollout.activate_user(:new_theme, @site)

FYI:

• rollout gem