View Source Instream

InfluxDB driver for Elixir

influxdb-support

InfluxDB Support

Tested InfluxDB versions:

  • 1.7.11
  • 1.8.10
  • 2.0.9
  • 2.1.1
  • 2.2.0

package-setup

Package Setup

To use Instream with your projects, edit your mix.exs file and add the required dependencies:

defp deps do
  [
    # ...
    {:instream, "~> 2.0"},
    # ...
  ]
end

testing

Testing

To run the tests you need to have HTTP authentication enabled.

The following environment variables are used to select some test suites and the InfluxDB version under test:

  • INFLUXDB_VERSION: one of "1.7", "1.8", "2.0", "2.1", or "2.2"
  • INFLUXDB_PORT_UDP: the UDP port used for writer testing (InfluxDB 1.x only)
  • INFLUXDB_SOCKET: path to the InfluxDB unix socket (InfluxDB 1.8 only)
  • INFLUXDB_TOKEN: the authentication token used (InfluxDB 2.x only)

usage

Usage

connections

Connections

To connect to an InfluxDB server you need a connection module:

defmodule MyConnection do
  use Instream.Connection, otp_app: :my_app
end

The :otp_app name and the name of the module can be freely chosen but have to be linked to a corresponding configuration entry. This defined connection module needs to be hooked up into your supervision tree:

children = [
  # ...
  MyConnection,
  # ...
]

Example of the matching configuration entry:

# InfluxDB v2.x
config :my_app, MyConnection,
  auth: [method: :token, token: "my_token"],
  bucket: "my_default_bucket",
  org: "my_default_org",
  host: "my.influxdb.host",
  version: :v2

# InfluxDB v1.x
config :my_app, MyConnection,
  auth: [username: "my_username", password: "my_password"],
  database: "my_default_database",
  host: "my.influxdb.host"

More details on connections and configuration options can be found with the Instream.Connection and Instream.Connection.Config modules.

queries

Queries

# Flux query
MyConnection.query(
  """
    from(bucket: "#{MyConnection.config(:bucket)}")
    |> range(start: -5m)
    |> filter(fn: (r) =>
      r._measurement == "instream_examples"
    )
    |> first()
  """
)

# InfluxQL query
MyConnection.query("SELECT * FROM instream_examples")

A more detailed documentation on queries (reading/writing/options) is available in the documentation for the modules Instream and Instream.Connection.

series-definitions

Series Definitions

If you do not want to define the raw maps for writing data you can pre-define a series for later usage:

defmodule MySeries do
  use Instream.Series

  series do
    measurement "my_measurement"

    tag :bar
    tag :foo

    field :value
  end
end

More information about series definitions can be found in the module documentation of Instream.Series.

writing-series-points

Writing Series Points

You can then use this module to assemble a data point (one at a time) for writing:

data = %MySeries{}
data = %{data | fields: %{data.fields | value: 17}}
data = %{data | tags: %{data.tags | bar: "bar", foo: "foo"}}

And then write one or many at once:

MyConnection.write(point)
MyConnection.write([point_1, point_2, point_3])

license

License

Apache License, Version 2.0