Class: Synthra::APIServer

Inherits:
Object
  • Object
show all
Defined in:
lib/synthra/api_server.rb

Overview

Production API Server

A production-ready API server for data generation. Designed to be the core of your data generation platform.

Examples:

Start standalone server

Synthra::APIServer.start(
  schema_dir: "schemas/",
  port: 3000,
  environment: :production
)

Use as Rack middleware

# config.ru
require 'synthra'
run Synthra::APIServer.rack_app(schema_dir: "schemas/")

With authentication

Synthra::APIServer.start(
  schema_dir: "schemas/",
  auth: { type: :api_key, keys: ["secret-key-123"] }
)

Defined Under Namespace

Classes: Cache, Metrics, RackRequest, RackResponse, RateLimiter, WEBrickRequest, WEBrickResponse

Constant Summary collapse

VERSION = 
"1.0.0"
DEFAULT_CONFIG =

Server configuration defaults

{
  port: 3000,
  host: "0.0.0.0",
  environment: :development,
  cors: true,
  rate_limit: 0,
  max_batch_size: 10_000,
  max_stream_size: 1_000_000,
  auth: nil,
  log_level: :info,
  request_timeout: 30,
  enable_metrics: true,
  enable_caching: false,
  cache_ttl: 60
}.freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(schema_dir:, **config) ⇒ APIServer

Create a new API server

Parameters:

  • schema_dir (String) —

    directory containing DSL schemas

  • config (Hash) —

    server configuration



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# File 'lib/synthra/api_server.rb', line 59

def initialize(schema_dir:, **config)
  @config = DEFAULT_CONFIG.merge(config)
  @registry = Registry.new
  @registry.load_dir(schema_dir)
  @metrics = Metrics.new if @config[:enable_metrics]
  @cache = Cache.new(@config[:cache_ttl]) if @config[:enable_caching]
  @rate_limiter = RateLimiter.new(@config[:rate_limit]) if @config[:rate_limit] > 0
end

Instance Attribute Details

#config ⇒ Object (readonly)

Returns the value of attribute config.



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# File 'lib/synthra/api_server.rb', line 35

def config
  @config
end

#registry ⇒ Object (readonly)

Returns the value of attribute registry.



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# File 'lib/synthra/api_server.rb', line 35

def registry
  @registry
end

Class Method Details

.rack_app(schema_dir:, **config) ⇒ Object

Rack application for use with Puma, etc.



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# File 'lib/synthra/api_server.rb', line 101

def self.rack_app(schema_dir:, **config)
  server = new(schema_dir: schema_dir, **config)
  
  lambda do |env|
    server.handle_rack_request(env)
  end
end

.start(**options) ⇒ Object 



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# File 'lib/synthra/api_server.rb', line 120

def start(**options)
  new(**options).start
end

Instance Method Details

#add_cors_headers(response) ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 450

def add_cors_headers(response)
  response.headers["Access-Control-Allow-Origin"] = "*"
  response.headers["Access-Control-Allow-Methods"] = "GET, POST, OPTIONS"
  response.headers["Access-Control-Allow-Headers"] = "Content-Type, Authorization, X-API-Key"
  response.headers["Access-Control-Max-Age"] = "86400"
end

#authenticate(request) ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 419

def authenticate(request)
  return true unless @config[:auth]

  case @config[:auth][:type]
  when :api_key
    # SECURITY: header only (never the query string — keys in URLs leak into access logs,
    # browser history and Referer headers) and a constant-time compare (Array#include? leaks
    # the key length/prefix via a timing oracle).
    secure_match?(request.headers["X-API-Key"], @config[:auth][:keys])
  when :bearer
    auth = request.headers["Authorization"]
    return false unless auth&.start_with?("Bearer ")

    secure_match?(auth[7..], @config[:auth][:tokens])
  else
    true
  end
end

#create_logger ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 168

def create_logger
  WEBrick::Log.new(
    $stderr,
    @config[:log_level] == :debug ? WEBrick::Log::DEBUG : WEBrick::Log::INFO
  )
end

#find_schema(slug) ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 398

def find_schema(slug)
  # Try exact match first
  return @registry.schema(slug) if @registry.schema?(slug)
  
  # Try PascalCase
  pascal = slug.split("_").map(&:capitalize).join
  return @registry.schema(pascal) if @registry.schema?(pascal)
  
  # Try case-insensitive match
  @registry.names.find { |n| n.downcase == slug.downcase }&.then { |n| @registry.schema(n) }
end

#handle_batch(request, response, schema_slug) ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 323

def handle_batch(request, response, schema_slug)
  schema = find_schema(schema_slug)
  return schema_not_found(response, schema_slug) unless schema
  
  params = request.query_params
  count = [[params[:count]&.to_i || 10, 1].max, @config[:max_batch_size]].min
  
  data = schema.generate_many(
    count,
    seed: params[:seed]&.to_i,
    mode: (params[:mode] || :random).to_sym,
    registry: @registry
  )
  
  response.json({
    data: data,
    meta: {
      count: data.length,
      schema: schema.name,
      seed: params[:seed]&.to_i,
      mode: params[:mode] || "random"
    }
  })
end

#handle_error(error, response) ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 457

def handle_error(error, response)
  response.status = 500
  response.json({
    error: error.class.name,
    message: error.message,
    backtrace: @config[:environment] == :development ? error.backtrace&.first(10) : nil
  })
end

#handle_generate(request, response, schema_slug) ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 274

def handle_generate(request, response, schema_slug)
  schema = find_schema(schema_slug)
  return schema_not_found(response, schema_slug) unless schema
  
  params = request.query_params
  cache_key = "#{schema.name}:#{params[:seed]}:#{params[:mode]}"
  
  if @cache && (cached = @cache.get(cache_key))
    response.json(cached)
    return
  end
  
  data = schema.generate(
    seed: params[:seed]&.to_i,
    mode: (params[:mode] || @config[:default_mode] || :random).to_sym,
    registry: @registry
  )
  
  @cache&.set(cache_key, data)
  response.json(data)
end

#handle_generate_post(request, response, schema_slug) ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 296

def handle_generate_post(request, response, schema_slug)
  schema = find_schema(schema_slug)
  return schema_not_found(response, schema_slug) unless schema
  
  body = request.json_body || {}
  count = [body["count"] || 1, @config[:max_batch_size]].min
  
  if count > 1
    data = schema.generate_many(
      count,
      seed: body["seed"]&.to_i,
      mode: (body["mode"] || :random).to_sym,
      overrides: body["overrides"] || {},
      registry: @registry
    )
  else
    data = schema.generate(
      seed: body["seed"]&.to_i,
      mode: (body["mode"] || :random).to_sym,
      overrides: body["overrides"] || {},
      registry: @registry
    )
  end
  
  response.json(data)
end

#handle_health(response) ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 252

def handle_health(response)
  response.json({
    status: "healthy",
    version: VERSION,
    schemas: @registry.names.count,
    uptime: uptime
  })
end

#handle_list_schemas(response) ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 261

def handle_list_schemas(response)
  response.json({
    schemas: @registry.names.sort.map do |name|
      schema = @registry.schema(name)
      {
        name: name,
        fields: schema.fields.count,
        endpoint: "/api/#{to_snake_case(name)}"
      }
    end
  })
end

#handle_metrics(response) ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 390

def handle_metrics(response)
  if @metrics
    response.json(@metrics.to_h)
  else
    response.json({ enabled: false })
  end
end

#handle_openapi(request, response, schema_slug) ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 364

def handle_openapi(request, response, schema_slug)
  schema = find_schema(schema_slug)
  return schema_not_found(response, schema_slug) unless schema
  
  # Create a mini registry with just this schema
  mini_registry = Registry.new
  mini_registry.register_schema(schema.name, schema)
  
  exporter = Export::OpenAPI.new(mini_registry)
  spec = exporter.export_as(request.query_params[:format]&.to_sym || :yaml)
  
  response.content_type = request.query_params[:format] == "json" ? "application/json" : "application/yaml"
  response.body = spec
end

#handle_protobuf(request, response, schema_slug) ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 379

def handle_protobuf(request, response, schema_slug)
  schema = find_schema(schema_slug)
  return schema_not_found(response, schema_slug) unless schema
  
  exporter = Export::Protobuf.new(schema, registry: @registry)
  proto = exporter.export
  
  response.content_type = "text/plain"
  response.body = proto
end

#handle_rack_request(env) ⇒ Object

Handle Rack request



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# File 'lib/synthra/api_server.rb', line 110

def handle_rack_request(env)
  request = RackRequest.new(env)
  response = RackResponse.new
  
  handle_request_internal(request, response)
  
  [response.status, response.headers, [response.body]]
end

#handle_request(req, res) ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 175

def handle_request(req, res)
  # :nocov: WEBrick mount_proc glue — wraps live WEBrick request/response objects.
  request = WEBrickRequest.new(req)
  response = WEBrickResponse.new(res)
  handle_request_internal(request, response)
  # :nocov:
end

#handle_request_internal(request, response) ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 183

def handle_request_internal(request, response)
  start_time = Time.now
  
  # CORS
  add_cors_headers(response) if @config[:cors]
  
  if request.options?
    response.status = 204
    return
  end
  
  # Authentication
  if @config[:auth] && !authenticate(request)
    response.status = 401
    response.json({ error: "Unauthorized" })
    return
  end
  
  # Rate limiting
  if @rate_limiter && @rate_limiter.limited?(request.client_ip)
    response.status = 429
    response.json({ error: "Rate limit exceeded", retry_after: @rate_limiter.retry_after(request.client_ip) })
    return
  end
  
  # Route
  route(request, response)
  
  # Metrics
  if @metrics
    @metrics.record(
      path: request.path,
      method: request.method,
      status: response.status,
      duration: Time.now - start_time
    )
  end
rescue StandardError => e
  handle_error(e, response)
end

#handle_stream(request, response, schema_slug) ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 348

def handle_stream(request, response, schema_slug)
  schema = find_schema(schema_slug)
  return schema_not_found(response, schema_slug) unless schema
  
  params = request.query_params
  count = [[params[:count]&.to_i || 100, 1].max, @config[:max_stream_size]].min
  
  response.content_type = "application/x-ndjson"
  
  output = +""
  schema.generate_stream(count: count, mode: (params[:mode] || :random).to_sym).each do |record|
    output << JSON.generate(record) << "\n"
  end
  response.body = output
end

#print_banner ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 127

def print_banner
  puts <<~BANNER
    
    ╔══════════════════════════════════════════════════════════════════╗
    ║                                                                  ║
    ║   🚀 Synthra API Server v#{VERSION}                            ║
    ║                                                                  ║
    ║   Production-Ready Data Generation API                           ║
    ║                                                                  ║
    ╠══════════════════════════════════════════════════════════════════╣
    ║                                                                  ║
    ║   Server:      http://#{@config[:host]}:#{@config[:port]}#{" " * (29 - @config[:host].length - @config[:port].to_s.length)}║
    ║   Environment: #{@config[:environment].to_s.ljust(42)}║
    ║   Schemas:     #{@registry.names.count.to_s.ljust(42)}║
    ║                                                                  ║
    ╚══════════════════════════════════════════════════════════════════╝
    
    📊 Available Schemas:
    #{@registry.names.map { |n| "   • #{n}" }.join("\n")}
    
    🔗 API Endpoints:
       GET  /                          Health check
       GET  /api/schemas               List schemas
       GET  /api/:schema               Generate record
       GET  /api/:schema/batch         Generate batch
       GET  /api/:schema/stream        Stream records (NDJSON)
       POST /api/:schema               Generate with overrides
       GET  /api/:schema/openapi       OpenAPI spec for schema
       GET  /api/:schema/protobuf      Protobuf spec for schema
       GET  /metrics                   Server metrics
    
    Press Ctrl+C to stop
    
  BANNER
end

#route(request, response) ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 224

def route(request, response)
  case request.path
  when "/"
    handle_health(response)
  when "/api/schemas"
    handle_list_schemas(response)
  when "/metrics"
    handle_metrics(response)
  when %r{^/api/([^/]+)/openapi$}
    handle_openapi(request, response, $1)
  when %r{^/api/([^/]+)/protobuf$}
    handle_protobuf(request, response, $1)
  when %r{^/api/([^/]+)/batch$}
    handle_batch(request, response, $1)
  when %r{^/api/([^/]+)/stream$}
    handle_stream(request, response, $1)
  when %r{^/api/([^/]+)$}
    if request.post?
      handle_generate_post(request, response, $1)
    else
      handle_generate(request, response, $1)
    end
  else
    response.status = 404
    response.json({ error: "Not found", path: request.path })
  end
end

#schema_not_found(response, slug) ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 410

def schema_not_found(response, slug)
  response.status = 404
  response.json({
    error: "Schema not found",
    requested: slug,
    available: @registry.names.map { |n| to_snake_case(n) }
  })
end

#secure_match?(provided, allowed) ⇒ Boolean (private)

Constant-time membership test against a list of secrets. fixed_length_secure_compare raises on length mismatch, so the bytesize guard short-circuits non-matches without leaking timing.

Returns:

  • (Boolean) 


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# File 'lib/synthra/api_server.rb', line 440

def secure_match?(provided, allowed)
  return false unless provided.is_a?(String) && allowed

  allowed.any? do |candidate|
    candidate.is_a?(String) &&
      candidate.bytesize == provided.bytesize &&
      OpenSSL.fixed_length_secure_compare(candidate, provided)
  end
end

#setup_signal_handlers ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 163

def setup_signal_handlers
  trap("INT") { stop }
  trap("TERM") { stop }
end

#start ⇒ Object

Start the server



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# File 'lib/synthra/api_server.rb', line 69

def start
  # :nocov: binds a real TCP port and blocks on WEBrick#start — exercised via integration use.
  print_banner
  setup_signal_handlers

  @server = WEBrick::HTTPServer.new(
    Port: @config[:port],
    BindAddress: @config[:host],
    Logger: create_logger,
    AccessLog: []
  )

  @server.mount_proc("/", &method(:handle_request))
  @server.start
  # :nocov:
end

#start_async ⇒ Object

Start in background



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# File 'lib/synthra/api_server.rb', line 87

def start_async
  # :nocov: spawns a thread that binds a port and sleeps — integration-only.
  @thread = Thread.new { start }
  sleep 0.5 # Wait for server to start
  @thread
  # :nocov:
end

#stop ⇒ Object

Stop the server



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# File 'lib/synthra/api_server.rb', line 96

def stop
  @server&.shutdown
end

#to_snake_case(str) ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 471

def to_snake_case(str)
  str.gsub(/([A-Z]+)([A-Z][a-z])/, '\1_\2')
     .gsub(/([a-z\d])([A-Z])/, '\1_\2')
     .downcase
end

#uptime ⇒ Object (private) 



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# File 'lib/synthra/api_server.rb', line 466

def uptime
  @start_time ||= Time.now
  (Time.now - @start_time).round
end