Segment

This is a non-official third-party client for Segment. Since version 2.0 it supports batch delivery of events and retries for the API.

Installation

Add segment to your list of dependencies in mix.exs.

def deps do
  [
    {:segment, "~> 0.2.6"}
  ]
end

Usage

Start the Segment agent with your write_key from Segment for a HTTP API Server Source

Segment.start_link("YOUR_WRITE_KEY")

There are then two ways to call the different methods on the API. A basic way through Segment.Analytics functions with either the full event Struct or some helper methods (also allowing Context and Integrations to be set manually).

This way will use the defined GenServer implementation such as Segment.Analytics.Batcher which will queue and batch events to Segment.

The other way is to drop down lower and use Segment.Http send and batch directly. This will require first creating a client with Segment.Http.client/1/Segment.Http.client/2

Track

Segment.Analytics.track(user_id, event, %{property1: "", property2: ""})

or the full way using a struct with all the possible options for the track call

%Segment.Analytics.Track{userId: "sdsds", event: "eventname", properties: %{property1: "", property2: ""}}
|> Segment.Analytics.track

Identify

Segment.Analytics.identify(user_id, %{trait1: "", trait2: ""})

Or the full way using a struct with all the possible options for the identify call.

%Segment.Analytics.Identify{userId: "sdsds", traits: %{trait1: "", trait2: ""}}
|> Segment.Analytics.identify

Screen

Segment.Analytics.screen(user_id, name)

Or the full way using a struct with all the possible options for the screen call.

%Segment.Analytics.Screen{userId: "sdsds", name: "dssd"}
|> Segment.Analytics.screen

Alias

Segment.Analytics.alias(user_id, previous_id)

Or the full way using a struct with all the possible options for the alias call.

%Segment.Analytics.Alias{userId: "sdsds", previousId: "dssd"}
|> Segment.Analytics.alias

Group

Segment.Analytics.group(user_id, group_id)

Or the full way using a struct with all the possible options for the group call.

%Segment.Analytics.Group{userId: "sdsds", groupId: "dssd"}
|> Segment.Analytics.group

Page

Segment.Analytics.page(user_id, name)

Or the full way using a struct with all the possible options for the page call.

%Segment.Analytics.Page{userId: "sdsds", name: "dssd"}
|> Segment.Analytics.page

Using the Segment Context

If you want to set the Context manually you should create a Segment.Analytics.Context struct with Segment.Analytics.Context.new/1

context = Segment.Analytics.Context.new(%{active: false})
Segment.Analytics.track(user_id, event, %{property1: "", property2: ""}, context)

Configuration

The library has a number of configuration options you can use to overwrite default values and behaviours

• config :segment, :sender_impl Allows selection of a sender implementation. At the moment this defaults to Segment.Analytics.Batcher which will send all events in batch. Change this value to Segment.Analytics.Sender to have all messages sent immediately (asynchronously)
• config :segment, :max_batch_size The maximum batch size of messages that will be sent to Segment at one time. Default value is 100.
• config :segment, :batch_every_ms The time (in ms) between every batch request. Default value is 2000 (2 seconds)
• config :segment, :retry_attempts The number of times to retry sending against the segment API. Default value is 3
• config :segment, :retry_expiry The maximum time (in ms) spent retrying. Default value is 10000 (10 seconds)
• config :segment, :retry_start The time (in ms) to start the first retry. Default value is 100
• config :segment, :send_to_http If set to false, the library will override the Tesla Adapter implementation to only log segment calls to debug but not make any actual API calls. This can be useful if you want to switch off Segment for test or dev. Default value is true
• config :segment, :tesla, :adapter This config option allows for overriding the HTTP Adapter for Tesla (which the library defaults to Hackney).This can be useful if you prefer something else, or want to mock the adapter for testing.
• config :segment, api_url: "https://self-hosted-segment-api.com/v1/" The Segment-compatible API endpoint that will receive your events. Defaults to https://api.segment.io/v1/. This setting is only useful if you are using Segment's EU instance or a Segment-compatible alternative API like Rudderstack.

Usage in Phoenix

This is how I add to a Phoenix project (may not be your preferred way)

1. Add the following to deps section of your mix.exs: {:segment, "~> 0.2.0"} and then mix deps.get

2. Add a config variable for your write_key (you may want to make this load from ENV) ie.

   config :segment,
     write_key: "2iFFnRsCfi"

3. Start the Segment GenServer in the supervised children list. In application.ex add to the children list:

   {Segment, Application.get_env(:segment, :write_key)}

Running tests

There are not many tests at the moment. if you want to run live tests on your account you need to change the config in test.exs to config :segment, :send_to_http, true and then provide your key as an environment variable.

SEGMENT_KEY=yourkey mix test

Telemetry

This package wraps its Segment event sending in :telemetry.span/3. You can attach to:

• [:segment, :send, :start]
• [:segment, :send, :stop]
• [:segment, :send, :exception]
• [:segment, :batch, :start]
• [:segment, :batch, :stop]
• [:segment, :batch, :exception]

The measurements will include, in Erlang's :native time unit (likely :nanosecond):

• system_time with :start events
• duration with :stop and :exception events

The metadata will include:

• the original event or events with all :send and :batch events respectively
• our status (:ok | :error) and Tesla's result with all :stop events
• error matching result when it isn't {:ok, env}
• kind, reason, and stacktrace with :exception events