Elixir Caddy

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release Hex.pm Documentation

Start Caddy reverse proxy server in Elixir project.

Manage caddy configuration in Elixir.

Add this in deps in mix.exs to install

{:caddy, "~> 2.1.3"}

If caddy bin is set, caddy server will automate start when application start.

Start in extra_applications

def application do
  [
    extra_applications: [Caddy.Application]
  ]
end
  • Notice

If caddy_bin is not specifiy, Caddy.Server will not start.

Set Caddy binary when needed.

Set caddy_bin to the path of Caddy binary file and start Caddy.Server.

Caddy.Config.set_bin("/usr/bin/caddy")
Caddy.restart_server()

This will restart server automatically

Caddy.Config.set_bin!("/usr/bin/caddy")

Config 

import Config

# dump caddy server log to stdout
config :caddy, dump_log: false

# caddy server will not start, this is useful for testing
config :caddy, start: false

# configure caddy paths
config :caddy, :base_path, "/custom/caddy/path"
config :caddy, :etc_path, "/custom/etc/path"
config :caddy, :run_path, "/custom/run/path"
config :caddy, :tmp_path, "/custom/tmp/path"
config :caddy, :env_file, "/custom/path/envfile"
config :caddy, :pid_file, "/custom/path/caddy.pid"

Telemetry

The library includes comprehensive telemetry support for monitoring Caddy operations. Telemetry events are emitted for:

  • Configuration changes: [:caddy, :config, :set], [:caddy, :config, :get], etc.
  • Server lifecycle: [:caddy, :server, :start], [:caddy, :server, :stop]
  • API operations: [:caddy, :api, :request], [:caddy, :api, :response]
  • File operations: [:caddy, :file, :read], [:caddy, :file, :write]
  • Validation: [:caddy, :validation, :success], [:caddy, :validation, :error]
  • Adaptation: [:caddy, :adapt, :success], [:caddy, :adapt, :error]

Usage Example 

# Attach telemetry handler
:telemetry.attach_many("caddy_handler", [
  [:caddy, :config, :set],
  [:caddy, :server, :start]
], fn event_name, measurements, metadata, _config ->
  IO.inspect({event_name, measurements, metadata})
end, %{})

# Start telemetry poller
Caddy.Telemetry.start_poller(30_000)

Available Functions