Phoenix Prometheus Setup

01-pheonix-prometheus-grafana.exs

...

 defp deps do
    [...
      {:prometheus, "~> 4.0", override: true},
      {:prometheus_ex, "~> 3.0"},
      {:prometheus_phoenix, "~> 1.2"},
      {:prometheus_plugs, "~> 1.1.5"},
      {:prometheus_ecto, "~> 1.0.1"},
      {:prometheus_process_collector, "~> 1.3.1"}
     ...]
  end
...

02-phoenix_instrumenter.ex

defmodule MyApp.Metrics.PhoenixInstrumenter do
  use Prometheus.PhoenixInstrumenter
end

03-ecto_instrumenter.ex

defmodule MyApp.Metrics.EctoInstrumenter do
  use Prometheus.EctoInstrumenter
end

04-pipeline_instrumenter.ex

defmodule MyApp.Metrics.PipelineInstrumenter do
  use Prometheus.PlugPipelineInstrumenter

  def label_value(:request_path, conn) do
    conn.request_path
  end
end

05-prometheus_exporter

defmodule MyApp.Metrics.PrometheusExporter do
  use Prometheus.PlugExporter
end

06-version_instrumenter.ex

defmodule MyApp.Metrics.VersionInstrumenter do
 use Prometheus.Metric

  def setup(otp_app) do
    gauge_name = String.to_atom("#{otp_app}_build_info")
    Gauge.declare([name: gauge_name,
                   help: help(otp_app),
                   labels: [:version],
                   registry: :default])

    Gauge.set([name: gauge_name,
               labels: [version(otp_app)],
               registry: :default], 1)
  end

  defp help(otp_app), do: "Build information for the currently deployed version of #{app_name(otp_app)}"

  defp app_name(otp_app), do: otp_app |> Atom.to_string() |> String.capitalize()

  defp version(otp_app), do: otp_app |> Application.spec() |> Keyword.get(:vsn) |> List.to_string
end
end

07-application.ex

defmodule MyApp do

  def start(_type, _args) do
    import Supervisor.Spec, warn: false

    require Prometheus.Registry
    MyApp.Metrics.PhoenixInstrumenter.setup()
    MyApp.Metrics.PipelineInstrumenter.setup()
    MyApp.Metrics.EctoInstrumenter.setup()
    Prometheus.Registry.register_collector(:prometheus_process_collector)
    MyApp.Metrics.PrometheusExporter.setup()
    MyApp.Metrics.VersionInstrumenter.setup(:my_app)
  ...

08-endpoint.ex

defmodule MyApp.Endpoint do
  plug MyApp.Metrics.PrometheusExporter
  plug MyApp.Metrics.PipelineInstrumenter

  plug MyApp.Router
end

09-config.exs

...

config :my_app, MyApp.Repo,
  ...
  loggers: [MyApp.Metrics.EctoInstrumenter, Ecto.LogEntry]

# Import environment specific config. This must remain at the bottom
# of this file so it overrides the configuration defined above.

config :prometheus, MyApp.Metrics.PhoenixInstrumenter,
  controller_call_labels: [:controller, :action],
  duration_buckets: [10, 25, 50, 100, 250, 500, 1000, 2500, 5000,
                     10_000, 25_000, 50_000, 100_000, 250_000, 500_000,
                     1_000_000, 2_500_000, 5_000_000, 10_000_000],
  registry: :default,
  duration_unit: :microseconds

config :prometheus, MyApp.Metrics.PipelineInstrumenter,
  labels: [:status_class, :method, :host, :scheme, :request_path],
  duration_buckets: [10, 100, 1_000, 10_000, 100_000,
                     300_000, 500_000, 750_000, 1_000_000,
                     1_500_000, 2_000_000, 3_000_000],
  registry: :default,
  duration_unit: :microseconds
...

10-prometheus-yml

# my global config
global:
  scrape_interval:     15s # Set the scrape interval to every 15 seconds. Default is every 1 minute.
  evaluation_interval: 15s # Evaluate rules every 15 seconds. The default is every 1 minute.
  # scrape_timeout is set to the global default (10s).

# Alertmanager configuration
alerting:
  alertmanagers:
  - static_configs:
    - targets:
      # - alertmanager:9093

# Load rules once and periodically evaluate them according to the global 'evaluation_interval'.
rule_files:
  # - "first_rules.yml"
  # - "second_rules.yml"

# A scrape configuration containing exactly one endpoint to scrape:
# Here it's Prometheus itself.
scrape_configs:
  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
  - job_name: 'prometheus'

    # metrics_path defaults to '/metrics'
    # scheme defaults to 'http'.

    static_configs:
    - targets: ['HOSTNAME:4000']
    

11-prometheus-docker

docker run \
-d \
-p 9090:9090 \
--name=tlive-prometheus \
--volume "$PWD/prometheus.yml:/etc/prometheus/prometheus.yml" \
prom/prometheus

12-grafana-docker

docker run \
-d \
-p 3001:3000 \
--name=tlive-grafana \
--user $ID \
--volume "$PWD/_data:/var/lib/grafana" \
-e "GF_PATHS_LOGS=/var/lib/grafana/logs" \
-e "GF_AUTH_ANONYMOUS_ENABLED=true" \
-e "GF_SECURITY_ADMIN_USER=admin" \
-e "GF_SECURITY_ADMIN_PASSWORD=admin" \
-e "GF_USERS_ALLOW_ORG_CREATE=false" \
-e "GF_USERS_ALLOW_SIGN_UP=false" \
grafana/grafana

13-Dashboards

https://github.com/deadtrickster/beam-dashboards