Module: PgReports::Standalone

Extended by:
Standalone
Included in:
Standalone
Defined in:
lib/pg_reports/standalone.rb

Overview

Runs the dashboard as a self-contained application, without a host Rails app.

It boots a minimal Rails::Application that mounts PgReports::Engine and points ActiveRecord::Base at a PostgreSQL database, then serves it over HTTP. This is what powers the pg_reports server executable and the pg_reports:server rake task, so the project can be launched straight from the gem's root folder.

Dependency note: this relies only on gems already pulled in transitively by the gem's runtime deps (rack via actionpack, rackup via railties). The actual web server (puma / webrick) is resolved at run time and is NOT a hard dependency — installed-gem users bring their own.

Defined Under Namespace

Classes: ServerUnavailable

Constant Summary collapse

DEFAULT_PORT = 
4000
DEFAULT_HOST = 
"127.0.0.1"
DEFAULT_MOUNT = 
"/"
CANDIDATE_SERVERS =

Rack handlers tried, in order, when none is named explicitly.

%w[puma webrick].freeze

Instance Method Summary collapse

Instance Method Details

#connection_url(explicit = nil) ⇒ Object

Resolve the connection URL. Priority: explicit url > DATABASE_URL > libpq-style PG* env vars (PGHOST/PGPORT/PGUSER/PGPASSWORD/PGDATABASE).



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# File 'lib/pg_reports/standalone.rb', line 56

def connection_url(explicit = nil)
  return explicit if explicit && !explicit.empty?
  return ENV["DATABASE_URL"] if ENV["DATABASE_URL"] && !ENV["DATABASE_URL"].empty?

  require "erb"
  user = ENV["PGUSER"] || ENV["USER"]
  password = ENV["PGPASSWORD"]
  host = ENV["PGHOST"] || "localhost"
  port = ENV["PGPORT"] || 5432
  database = ENV["PGDATABASE"] || "postgres"

  userinfo = +""
  if user && !user.empty?
    userinfo << ERB::Util.url_encode(user)
    userinfo << ":#{ERB::Util.url_encode(password)}" if password && !password.empty?
    userinfo << "@"
  end

  "postgresql://#{userinfo}#{host}:#{port}/#{ERB::Util.url_encode(database)}"
end

#run(port: DEFAULT_PORT, host: DEFAULT_HOST, mount_path: DEFAULT_MOUNT, database_url: nil, server: nil) ⇒ Object

Boot the app and start a (blocking) web server.

Parameters:

  • port (Integer) (defaults to: DEFAULT_PORT)
  • host (String) (defaults to: DEFAULT_HOST)
  • mount_path (String) (defaults to: DEFAULT_MOUNT) —

    where the engine is mounted (default "/")

  • database_url (String, nil) (defaults to: nil) —

    explicit connection URL; otherwise resolved from DATABASE_URL or libpq-style PG* env vars

  • server (String, nil) (defaults to: nil) —

    Rack handler name to force (e.g. "puma")



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# File 'lib/pg_reports/standalone.rb', line 37

def run(port: DEFAULT_PORT, host: DEFAULT_HOST, mount_path: DEFAULT_MOUNT,
  database_url: nil, server: nil)
  # Rails' ActiveRecord railtie reads the connection from DATABASE_URL when no
  # config/database.yml exists — so we route our resolved connection through
  # it. The connection registry then auto-registers it as the :primary target,
  # and database switching / multi-cluster all work unchanged.
  ENV["DATABASE_URL"] = connection_url(database_url)

  app = build_application(mount_path)
  app.initialize!
  verify_connection!

  handler_name, handler = resolve_server(server)
  banner(host: host, port: port, server: handler_name)
  handler.run(app, Host: host, Port: port)
end