Version: v0.17.3

Configure a flag

The goal of this module is to avoid having to host a backend to manage your feature flags and, to keep them centralized by using a single file as a source.

Your file must be a valid YAML, JSON or TOML file with a list of flags (examples: YAML, JSON, TOML).

Example

A flag configuration looks like:

YAML

test-flag:
  percentage: 100
  rule: key eq "random-key"
  true: true
  false: false
  default: false
  disable: false
  trackEvents: true
  rollout:
    experimentation:
      start: 2021-03-20T00:00:00.10-05:00
      end: 2021-03-21T00:00:00.10-05:00

test-flag2:
  rule: key eq "not-a-key"
  percentage: 100
  true: true
  false: false
  default: false

JSON

{
  "test-flag": {
    "percentage": 100,
    "rule": "key eq \"random-key\"",
    "true": true,
    "false": false,
    "default": false,
    "disable": false,
    "trackEvents": true,
    "rollout": {
      "experimentation": {
        "start": "2021-03-20T05:00:00.100Z",
        "end": "2021-03-21T05:00:00.100Z"
      }
    }
  },
  "test-flag2": {
    "rule": "key eq \"not-a-key\"",
    "percentage": 100,
    "true": true,
    "false": false,
    "default": false
  }
}

TOML

[test-flag]
percentage = 100.0
rule = "key eq \"random-key\""
true = true
false = false
default = false
disable = false
trackEvents = true

[test-flag.rollout]

    [test-flag.rollout.experimentation]
    start = 2021-03-20T05:00:00.100Z
    end = 2021-03-21T05:00:00.100Z

[test-flag2]
rule = "key eq \"not-a-key\""
percentage = 100.0
true = true
false = false
default = false

Format details

Field	Description
flag-key	The `flag-key` is the name of your flag. It must be unique. On the example the flag keys are `test-flag`* and `test-flag2`.*
`true`	The value return by the flag if apply to the user (rule is evaluated to true) and user is in the active percentage.
`false`	The value return by the flag if apply to the user (rule is evaluated to true) and user is not in the active percentage.
`default`	The value return by the flag if not apply to the user (rule is evaluated to false).
`percentage`	(optional) Percentage of the users affect by the flag. Default: 0 The percentage is compute by doing a hash of the user key (100000 variations), it means that you can have 3 numbers after the comma.
`rule`	(optional) This is the query use to select on which user the flag should apply. Rule format is describe in the rule format section. *If no rule set, the flag apply to all users (percentage still apply).*
`disable`	(optional) True if the flag is disabled. Default: `false`
`trackEvents`	(optional) False if you don't want to export the data in your data exporter. Default: `true`
`rollout`	(optional) `rollout` contains a specific rollout strategy you want to use. See rollout section for more details.

Rule format

The rule format is based on the nikunjy/rules library.

All the operations can be written capitalized or lowercase (ex: eq or EQ can be used).
Logical Operations supported are AND OR.

Compare Expression and their definitions (a|b means you can use either one of the two a or b):

Operator	Description
`eq` \| `==`	equals to
`ne` \| `!=`	not equals to
`lt` \| `<`	less than
`gt` \| `>`	greater than
`le` \| `<=`	less than equal to
`ge` \| `>=`	greater than equal to
`co`	contains
`sw`	starts with
`ew`	ends with
`in`	in a list
`pr`	present
`not`	not of a logical expression

Examples

Select a specific user: key eq "example@example.com"
Select all identified users: anonymous ne true
Select a user with a custom property: userId eq "12345"

Advanced configurations

You can have advanced configurations for your flag to have specific behavior for them, such as:

Configure a flag

Example​

YAML​

JSON​

TOML​

Format details​

Rule format​

Examples​

Advanced configurations​

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