simple_client.rb in wcc-contentful-1.0.0.pre.rc1

- old
+ new

@@ -1,9 +1,10 @@
 # frozen_string_literal: true
 
 require_relative 'simple_client/response'
 require_relative 'simple_client/management'
+require_relative 'instrumentation'
 
 module WCC::Contentful
   # The SimpleClient accesses the Contentful CDN to get JSON responses,
   # returning the raw JSON data as a parsed hash.  This is the bottom layer of
   # the WCC::Contentful gem.
@@ -14,39 +15,47 @@
   #
   # It can be configured to access any API url and exposes only a single method,
   # `get`.  This method returns a WCC::Contentful::SimpleClient::Response
   # that handles paging automatically.
   #
-  # The SimpleClient by default uses 'http' to perform the gets, but any HTTP
-  # client can be injected by passing a proc as the `adapter:` option.
+  # The SimpleClient by default uses 'faraday' to perform the gets, but any HTTP
+  # client adapter be injected by passing the `connection:` option.
   #
   # @api Client
   class SimpleClient
+    include WCC::Contentful::Instrumentation
+
     attr_reader :api_url
     attr_reader :space
 
     # Creates a new SimpleClient with the given configuration.
     #
     # @param [String] api_url the base URL of the Contentful API to connect to
     # @param [String] space The Space ID to access
     # @param [String] access_token A Contentful Access Token to be sent in the Authorization header
     # @param [Hash] options The remaining optional parameters, defined below
-    # @option options [Symbol, Object] adapter The Adapter to use to make requests.
+    # @option options [Symbol, Object] connection The Faraday connection to use to make requests.
     #   Auto-discovered based on what gems are installed if this is not provided.
     # @option options [String] default_locale The locale query param to set by default.
     # @option options [String] environment The contentful environment to access. Defaults to 'master'.
     # @option options [Boolean] no_follow_redirects If true, do not follow 300 level redirects.
+    # @option options [Number] rate_limit_wait_timeout The maximum time to block the thread waiting
+    #   on a rate limit response.  By default will wait for one 429 and then fail on the second 429.
     def initialize(api_url:, space:, access_token:, **options)
       @api_url = URI.join(api_url, '/spaces/', space + '/')
       @space = space
       @access_token = access_token
 
-      @adapter = SimpleClient.load_adapter(options[:adapter])
+      @adapter = SimpleClient.load_adapter(options[:connection])
 
       @options = options
+      @_instrumentation = @options[:instrumentation]
       @query_defaults = {}
       @query_defaults[:locale] = @options[:default_locale] if @options[:default_locale]
+      # default 1.5 so that we retry one time then fail if still rate limited
+      # https://www.contentful.com/developers/docs/references/content-preview-api/#/introduction/api-rate-limits
+      @rate_limit_wait_timeout = @options[:rate_limit_wait_timeout] || 1.5
 
       return unless options[:environment].present?
 
       @api_url = URI.join(@api_url, 'environments/', options[:environment] + '/')
     end
@@ -55,17 +64,21 @@
     # space and environment.  Query parameters are merged with the defaults and
     # appended to the request.
     def get(path, query = {})
       url = URI.join(@api_url, path)
 
+      resp =
+        _instrument 'get_http', url: url, query: query do
+          get_http(url, query)
+        end
       Response.new(self,
         { url: url, query: query },
-        get_http(url, query))
+        resp)
     end
 
     ADAPTERS = {
-      http: ['http', '> 1.0', '< 3.0'],
+      faraday: ['faraday', '>= 0.9'],
       typhoeus: ['typhoeus', '~> 1.0']
     }.freeze
 
     def self.load_adapter(adapter)
       case adapter
@@ -78,41 +91,65 @@
             next
           end
         end
         raise ArgumentError, 'Unable to load adapter!  Please install one of '\
           "#{ADAPTERS.values.map(&:join).join(',')}"
-      when :http
-        require_relative 'simple_client/http_adapter'
-        HttpAdapter.new
+      when :faraday
+        require 'faraday'
+        ::Faraday.new do |faraday|
+          faraday.response :logger, (Rails.logger if defined?(Rails)), { headers: false, bodies: false }
+          faraday.adapter :net_http
+        end
       when :typhoeus
         require_relative 'simple_client/typhoeus_adapter'
         TyphoeusAdapter.new
       else
-        unless adapter.respond_to?(:call)
+        unless adapter.respond_to?(:get)
           raise ArgumentError, "Adapter #{adapter} is not invokeable!  Please "\
-            "pass a proc or use one of #{ADAPTERS.keys}"
+            "pass use one of #{ADAPTERS.keys} or create a Faraday-compatible adapter"
         end
         adapter
       end
     end
 
     private
 
-    def get_http(url, query, headers = {}, proxy = {})
+    def _instrumentation_event_prefix
+      # Unify all CDN, Management, Preview notifications under same namespace
+      '.simpleclient.contentful.wcc'
+    end
+
+    def get_http(url, query, headers = {})
       headers = {
         Authorization: "Bearer #{@access_token}"
       }.merge(headers || {})
 
       q = @query_defaults.dup
       q = q.merge(query) if query
 
-      resp = @adapter.call(url, q, headers, proxy)
+      start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+      loop do
+        resp = @adapter.get(url, q, headers)
 
-      if [301, 302, 307].include?(resp.code) && !@options[:no_follow_redirects]
-        resp = get_http(resp.headers['location'], nil, headers, proxy)
+        if [301, 302, 307].include?(resp.status) && !@options[:no_follow_redirects]
+          url = resp.headers['Location']
+          next
+        end
+
+        if resp.status == 429 &&
+            reset = resp.headers['X-Contentful-RateLimit-Reset'].presence
+          reset = reset.to_f
+          _instrument 'rate_limit', start: start, reset: reset, timeout: @rate_limit_wait_timeout
+          now = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+          if (now - start) + reset < @rate_limit_wait_timeout
+            sleep(reset)
+            next
+          end
+        end
+
+        return resp
       end
-      resp
     end
 
     # The CDN SimpleClient accesses 'https://cdn.contentful.com' to get raw
     # JSON responses.  It exposes methods to query entries, assets, and content_types.
     # The responses are instances of WCC::Contentful::SimpleClient::Response
@@ -133,35 +170,50 @@
         'cdn'
       end
 
       # Gets an entry by ID
       def entry(key, query = {})
-        resp = get("entries/#{key}", query)
+        resp =
+          _instrument 'entries', id: key, type: 'Entry', query: query do
+            get("entries/#{key}", query)
+          end
         resp.assert_ok!
       end
 
       # Queries entries with optional query parameters
       def entries(query = {})
-        resp = get('entries', query)
+        resp =
+          _instrument 'entries', type: 'Entry', query: query do
+            get('entries', query)
+          end
         resp.assert_ok!
       end
 
       # Gets an asset by ID
       def asset(key, query = {})
-        resp = get("assets/#{key}", query)
+        resp =
+          _instrument 'entries', type: 'Asset', id: key, query: query do
+            get("assets/#{key}", query)
+          end
         resp.assert_ok!
       end
 
       # Queries assets with optional query parameters
       def assets(query = {})
-        resp = get('assets', query)
+        resp =
+          _instrument 'entries', type: 'Asset', query: query do
+            get('assets', query)
+          end
         resp.assert_ok!
       end
 
       # Queries content types with optional query parameters
       def content_types(query = {})
-        resp = get('content_types', query)
+        resp =
+          _instrument 'content_types', query: query do
+            get('content_types', query)
+          end
         resp.assert_ok!
       end
 
       # Accesses the Sync API to get a list of items that have changed since
       # the last sync.
@@ -175,22 +227,26 @@
             { sync_token: sync_token }
           else
             { initial: true }
           end
         query = query.merge(sync_token)
-        resp = SyncResponse.new(get('sync', query))
+        resp =
+          _instrument 'sync', sync_token: sync_token, query: query do
+            get('sync', query)
+          end
+        resp = SyncResponse.new(resp)
         resp.assert_ok!
       end
     end
 
     # @api Client
     class Preview < Cdn
       def initialize(space:, preview_token:, **options)
         super(
-          api_url: options[:api_url] || 'https://preview.contentful.com/',
+          **options,
+          api_url: options[:preview_api_url] || 'https://preview.contentful.com/',
           space: space,
-          access_token: preview_token,
-          **options
+          access_token: preview_token
         )
       end
 
       def client_type
         'preview'