defmodule Appsignal do
@moduledoc """
AppSignal for Elixir. Follow the [installation
guide](https://docs.appsignal.com/elixir/installation.html) to install
AppSignal into your Elixir app.
This module contains the main AppSignal OTP application, as well as a few
helper functions for sending metrics to AppSignal.
"""
require Mix.Appsignal.Utils
@os Mix.Appsignal.Utils.compile_env(:appsignal, :os_internal, :os)
use Application
alias Appsignal.Config
require Logger
@doc false
def start(_type, _args) do
import Supervisor.Spec, warn: false
initialize()
if Config.error_backend_enabled?() do
Appsignal.Error.Backend.attach()
end
Appsignal.Ecto.attach()
Appsignal.Finch.attach()
children = [
{Appsignal.Tracer, []},
{Appsignal.Monitor, []},
{Appsignal.Probes, []}
]
result = Supervisor.start_link(children, strategy: :one_for_one, name: Appsignal.Supervisor)
# Add our default system probes. It's important that this is called after
# the Suportvisor has started. Otherwise the GenServer cannot register the
# probe.
add_default_probes()
result
end
@doc false
def stop(_state) do
Appsignal.IntegrationLogger.debug("AppSignal stopping.")
end
@doc false
def config_change(_changed, _new, _removed) do
# Spawn a separate process that reloads the configuration. AppSignal can't
# reload it in the same process because the GenServer would continue
# calling itself once it reached `Application.put_env` in
# `Appsignal.Config`.
spawn(fn ->
Appsignal.Nif.stop()
initialize()
end)
:ok
end
@doc false
@spec initialize() :: :ok
def initialize do
case {Config.initialize(), Config.configured_as_active?()} do
{_, false} ->
Logger.info("AppSignal disabled.")
{:ok, true} ->
Appsignal.IntegrationLogger.debug("AppSignal starting.")
Config.write_to_environment()
Appsignal.Nif.start()
if Appsignal.Nif.loaded?() do
Appsignal.IntegrationLogger.debug("AppSignal started.")
else
log_nif_loading_error()
end
{{:error, :invalid_config}, true} ->
Logger.warn(
"Warning: No valid AppSignal configuration found, continuing with " <>
"AppSignal metrics disabled."
)
end
end
@doc false
def add_default_probes do
# This is a workaround for https://github.com/erlang/otp/issues/5425.
:erlang.system_flag(:scheduler_wall_time, true)
Appsignal.Probes.register(:erlang, &Appsignal.Probes.ErlangProbe.call/1)
end
@doc """
Set a gauge for a measurement of a metric.
"""
@spec set_gauge(String.t(), float | integer, map) :: :ok
def set_gauge(key, value, tags \\ %{})
def set_gauge(key, value, tags) when is_integer(value) do
set_gauge(key, value + 0.0, tags)
end
def set_gauge(key, value, %{} = tags) when is_float(value) do
encoded_tags = Appsignal.Utils.DataEncoder.encode(tags)
:ok = Appsignal.Nif.set_gauge(key, value, encoded_tags)
end
@doc """
Increment a counter of a metric.
"""
@spec increment_counter(String.t(), number, map) :: :ok
def increment_counter(key, count \\ 1, tags \\ %{})
def increment_counter(key, count, %{} = tags) when is_number(count) do
encoded_tags = Appsignal.Utils.DataEncoder.encode(tags)
:ok = Appsignal.Nif.increment_counter(key, count + 0.0, encoded_tags)
end
@doc """
Add a value to a distribution
Use this to collect multiple data points that will be merged into a graph.
"""
@spec add_distribution_value(String.t(), float | integer, map) :: :ok
def add_distribution_value(key, value, tags \\ %{})
def add_distribution_value(key, value, tags) when is_integer(value) do
add_distribution_value(key, value + 0.0, tags)
end
def add_distribution_value(key, value, %{} = tags) when is_float(value) do
encoded_tags = Appsignal.Utils.DataEncoder.encode(tags)
:ok = Appsignal.Nif.add_distribution_value(key, value, encoded_tags)
end
defdelegate instrument(fun), to: Appsignal.Instrumentation
defdelegate instrument(name, fun), to: Appsignal.Instrumentation
defdelegate instrument(name, category, fun), to: Appsignal.Instrumentation
defdelegate set_error(exception, stacktrace), to: Appsignal.Instrumentation
defdelegate set_error(kind, reason, stacktrace), to: Appsignal.Instrumentation
defdelegate send_error(exception, stacktrace), to: Appsignal.Instrumentation
defdelegate send_error(kind, reason, stacktrace), to: Appsignal.Instrumentation
defdelegate send_error(kind, reason, stacktrace, fun), to: Appsignal.Instrumentation
defp log_nif_loading_error do
arch = parse_architecture(to_string(:erlang.system_info(:system_architecture)))
{_, target_list} = @os.type()
target = to_string(target_list)
{install_arch, install_target} = fetch_installed_architecture_target()
if arch == install_arch && target == install_target do
Appsignal.IntegrationLogger.error(
"AppSignal failed to load the extension. Please run the diagnose tool and email us at support@appsignal.com: https://docs.appsignal.com/elixir/command-line/diagnose.html\n",
stderr: true
)
else
Appsignal.IntegrationLogger.error(
"The AppSignal NIF was installed for architecture '#{install_arch}-#{install_target}', but the current architecture is '#{arch}-#{target}'. Please reinstall the AppSignal package on the host the app is started: mix deps.compile appsignal --force",
stderr: true
)
end
end
# Parse install report and fetch the architecture and target
defp fetch_installed_architecture_target do
case File.read(Path.join([:code.priv_dir(:appsignal), "install.report"])) do
{:ok, raw_report} ->
case Appsignal.Json.decode(raw_report) do
{:ok, report} ->
%{"build" => %{"architecture" => arch, "target" => target}} = report
{parse_architecture(arch), target}
{:error, reason} ->
Appsignal.IntegrationLogger.error(
"Failed to parse the AppSignal 'install.report' file: #{inspect(reason)}",
stderr: true
)
{"unknown", "unknown"}
end
{:error, reason} ->
Appsignal.IntegrationLogger.error(
"Failed to read the AppSignal 'install.report' file: #{inspect(reason)}",
stderr: true
)
{"unknown", "unknown"}
end
end
# Transform `aarch64-apple-darwin21.3.0` to `aarch64`
defp parse_architecture(arch_parts) do
List.first(String.split(arch_parts, "-", parts: 2))
end
end