Remove instrumentation

Previously we used logplex to collect production performance statistics. It worked like this. We collect the stats, then stream them to a logplex app endpoint using l2met format. A logplex drain read from the data, serialized it into a Postgres database where we later wrote custom dashboards via SQL queries to find places to optimize.

That setup was ad-hoc. After we did the immediate perf work we decommissioned the drain and the Postgres database. We didn't remove the logplex integration or the instrumentation partially because we didn't know if we would need to do another round of performance analysis and partially because it was believed not removing it was "safer" (when this happened there were far fewer tests on the buildpack and developing on it was a far riskier endeavor).

We haven't used this in years and are in the process of re-writing the Ruby buildpack. Any future instrumentation and performance analysis will be done away from this codebase. We can safely remove the instrumentation, lpxc (used to send logs to the endpoint), dontenv (used to source the environment variable for logplex), and the logic around preserving and copying the `.env` file from prior builds.

#GUS-W-8216066

CHANGELOG.md

@@ -2,9 +2,11 @@
 
 ## Main (unreleased)
 
+* Remove instrumentation and LPXC logic (https://github.com/heroku/heroku-buildpack-ruby/pull/1229)
+
 ## v232 (11/9/2021)
 
-* Deactivate LXPC (https://github.com/heroku/heroku-buildpack-ruby/pull/1228)
+* Deactivate LPXC (https://github.com/heroku/heroku-buildpack-ruby/pull/1228)
 
 ## v231 (10/27/2021)
 

bin/support/ruby_build

@@ -18,13 +18,11 @@ ENV_DIR="#{PLATFORM_DIR}/env"
 PLAN=ARGV[3]
 
 begin
-  LanguagePack::Instrument.trace 'compile', 'app.compile' do
-    LanguagePack::ShellHelpers.initialize_env(ENV_DIR)
-    if pack = LanguagePack.detect(ARGV[0], nil, LAYER_DIR)
-      pack.topic("Compiling #{pack.name}")
-      pack.log("compile") do
-        pack.build
-      end
+  LanguagePack::ShellHelpers.initialize_env(ENV_DIR)
+  if pack = LanguagePack.detect(ARGV[0], nil, LAYER_DIR)
+    pack.topic("Compiling #{pack.name}")
+    pack.log("compile") do
+      pack.build
     end
   end
 rescue Exception => e

bin/support/ruby_compile

@@ -12,13 +12,11 @@ require "language_pack"
 require "language_pack/shell_helpers"
 
 begin
-  LanguagePack::Instrument.trace 'compile', 'app.compile' do
-    LanguagePack::ShellHelpers.initialize_env(ARGV[2])
-    if pack = LanguagePack.detect(ARGV[0], ARGV[1])
-      pack.topic("Compiling #{pack.name}")
-      pack.log("compile") do
-        pack.compile
-      end
+  LanguagePack::ShellHelpers.initialize_env(ARGV[2])
+  if pack = LanguagePack.detect(ARGV[0], ARGV[1])
+    pack.topic("Compiling #{pack.name}")
+    pack.log("compile") do
+      pack.compile
     end
   end
 rescue Exception => e

bin/support/ruby_test-compile

@@ -19,13 +19,11 @@ require "language_pack/test"
 include LanguagePack::ShellHelpers
 
 begin
-  LanguagePack::Instrument.trace 'test_compile', 'app.test_compile' do
-    if pack = LanguagePack.detect(ARGV[0], ARGV[1])
-      LanguagePack::ShellHelpers.initialize_env(ARGV[2])
-      pack.topic("Setting up Test for #{pack.name}")
-      pack.log("test_compile") do
-        pack.compile
-      end
+  if pack = LanguagePack.detect(ARGV[0], ARGV[1])
+    LanguagePack::ShellHelpers.initialize_env(ARGV[2])
+    pack.topic("Setting up Test for #{pack.name}")
+    pack.log("test_compile") do
+      pack.compile
     end
   end
 rescue Exception => e

buildpack.toml

@@ -11,11 +11,6 @@ ruby_version = "2.7.4"
 [publish.Ignore]
 files = ["spec/"]
 
-[[publish.Vendor]]
-url = "https://codon-buildpacks.s3.amazonaws.com/buildpacks/heroku/ruby.tgz"
-dir = "."
-files = ["./.env"]
-
 [[publish.Vendor]]
 url = "https://s3-external-1.amazonaws.com/heroku-buildpack-ruby/heroku-18/ruby-2.7.4.tgz"
 dir = "vendor/ruby/heroku-18"

lib/language_pack.rb

@@ -10,25 +10,20 @@ module Helpers
   # @param [Array] first argument is a String of the build directory
   # @return [LanguagePack] the {LanguagePack} detected
   def self.detect(*args)
-    Instrument.instrument 'detect' do
-      Dir.chdir(args.first)
+    Dir.chdir(args.first)
 
-      pack = [ NoLockfile, Rails7, Rails6, Rails5, Rails42, Rails41, Rails4, Rails3, Rails2, Rack, Ruby ].detect do |klass|
-        klass.use?
-      end
-
-      return pack ? pack.new(*args) : nil
+    pack = [ NoLockfile, Rails7, Rails6, Rails5, Rails42, Rails41, Rails4, Rails3, Rails2, Rack, Ruby ].detect do |klass|
+      klass.use?
     end
+
+    return pack ? pack.new(*args) : nil
   end
 end
 
-
 $:.unshift File.expand_path("../../vendor", __FILE__)
 $:.unshift File.expand_path("..", __FILE__)
 
-require 'dotenv'
 require 'language_pack/shell_helpers'
-require 'language_pack/instrument'
 require "language_pack/helpers/plugin_installer"
 require "language_pack/helpers/stale_file_cleaner"
 require "language_pack/helpers/rake_runner"

lib/language_pack/base.rb

@@ -8,7 +8,6 @@
 require "language_pack/helpers/layer"
 require "language_pack/metadata"
 require "language_pack/fetcher"
-require "language_pack/instrument"
 
 Encoding.default_external = Encoding::UTF_8 if defined?(Encoding)
 ENV["BPLOG_PREFIX"] = "buildpack.ruby"
@@ -28,26 +27,16 @@ class LanguagePack::Base
   # @param [String] the path of the build dir
   # @param [String] the path of the cache dir this is nil during detect and release
   def initialize(build_path, cache_path = nil, layer_dir=nil)
-     self.class.instrument "base.initialize" do
-      @build_path    = build_path
-      @stack         = ENV.fetch("STACK")
-      @cache         = LanguagePack::Cache.new(cache_path)
-      @metadata      = LanguagePack::Metadata.new(@cache)
-      @bundler_cache = LanguagePack::BundlerCache.new(@cache, @stack)
-      @id            = Digest::SHA1.hexdigest("#{Time.now.to_f}-#{rand(1000000)}")[0..10]
-      @fetchers      = {:buildpack => LanguagePack::Fetcher.new(VENDOR_URL) }
-      @layer_dir     = layer_dir
-
-      Dir.chdir build_path
-    end
-  end
-
-  def instrument(*args, &block)
-    self.class.instrument(*args, &block)
-  end
-
-  def self.instrument(*args, &block)
-    LanguagePack::Instrument.instrument(*args, &block)
+    @build_path    = build_path
+    @stack         = ENV.fetch("STACK")
+    @cache         = LanguagePack::Cache.new(cache_path)
+    @metadata      = LanguagePack::Metadata.new(@cache)
+    @bundler_cache = LanguagePack::BundlerCache.new(@cache, @stack)
+    @id            = Digest::SHA1.hexdigest("#{Time.now.to_f}-#{rand(1000000)}")[0..10]
+    @fetchers      = {:buildpack => LanguagePack::Fetcher.new(VENDOR_URL) }
+    @layer_dir     = layer_dir
+
+    Dir.chdir build_path
   end
 
   def self.===(build_path)
@@ -82,40 +71,36 @@ def default_process_types
   # this is called to build the slug
   def compile
     write_release_yaml
-    instrument 'base.compile' do
+    Kernel.puts ""
+    warnings.each do |warning|
+      Kernel.puts "\e[1m\e[33m###### WARNING:\e[0m"# Bold yellow
       Kernel.puts ""
-      warnings.each do |warning|
-        Kernel.puts "\e[1m\e[33m###### WARNING:\e[0m"# Bold yellow
-        Kernel.puts ""
-        puts warning
-        Kernel.puts ""
-      end
-      if deprecations.any?
-        topic "DEPRECATIONS:"
-        puts @deprecations.join("\n")
-      end
+      puts warning
       Kernel.puts ""
     end
+    if deprecations.any?
+      topic "DEPRECATIONS:"
+      puts @deprecations.join("\n")
+    end
+    Kernel.puts ""
     mcount "success"
   end
 
   def build
     write_release_toml
-    instrument 'base.compile' do
+    Kernel.puts ""
+    warnings.each do |warning|
+      Kernel.puts "\e[1m\e[33m###### WARNING:\e[0m"# Bold yellow
+      Kernel.puts ""
+      puts warning
       Kernel.puts ""
-      warnings.each do |warning|
-        Kernel.puts "\e[1m\e[33m###### WARNING:\e[0m"# Bold yellow
-        Kernel.puts ""
-        puts warning
-        Kernel.puts ""
-        Kernel.puts ""
-      end
-      if deprecations.any?
-        topic "DEPRECATIONS:"
-        puts @deprecations.join("\n")
-      end
       Kernel.puts ""
     end
+    if deprecations.any?
+      topic "DEPRECATIONS:"
+      puts @deprecations.join("\n")
+    end
+    Kernel.puts ""
     mcount "success"
   end
 

lib/language_pack/helpers/bundler_wrapper.rb

@@ -100,10 +100,8 @@ def has_gem?(name)
   end
 
   def gem_version(name)
-    instrument "ruby.gem_version" do
-      if spec = specs[name]
-        spec.version
-      end
+    if spec = specs[name]
+      spec.version
     end
   end
 
@@ -131,29 +129,23 @@ def dir_name
     "bundler-#{version}"
   end
 
-  def instrument(*args, &block)
-    LanguagePack::Instrument.instrument(*args, &block)
-  end
-
   def ruby_version
-    instrument 'detect_ruby_version' do
-      env = { "PATH"     => "#{bundler_path}/bin:#{ENV['PATH']}",
-              "RUBYLIB"  => File.join(bundler_path, "gems", dir_name, "lib"),
-              "GEM_PATH" => "#{bundler_path}:#{ENV["GEM_PATH"]}",
-              "BUNDLE_DISABLE_VERSION_CHECK" => "true"
-            }
-      command = "bundle platform --ruby"
-
-      # Silently check for ruby version
-      output  = run_stdout(command, user_env: true, env: env).strip.lines.last
-
-      # If there's a gem in the Gemfile (i.e. syntax error) emit error
-      raise GemfileParseError.new(run("bundle check", user_env: true, env: env)) unless $?.success?
-      if output.match(/No ruby version specified/)
-        ""
-      else
-        output.strip.sub('(', '').sub(')', '').sub(/(p-?\d+)/, ' \1').split.join('-')
-      end
+    env = { "PATH"     => "#{bundler_path}/bin:#{ENV['PATH']}",
+            "RUBYLIB"  => File.join(bundler_path, "gems", dir_name, "lib"),
+            "GEM_PATH" => "#{bundler_path}:#{ENV["GEM_PATH"]}",
+            "BUNDLE_DISABLE_VERSION_CHECK" => "true"
+          }
+    command = "bundle platform --ruby"
+
+    # Silently check for ruby version
+    output  = run_stdout(command, user_env: true, env: env).strip.lines.last
+
+    # If there's a gem in the Gemfile (i.e. syntax error) emit error
+    raise GemfileParseError.new(run("bundle check", user_env: true, env: env)) unless $?.success?
+    if output.match(/No ruby version specified/)
+      ""
+    else
+      output.strip.sub('(', '').sub(')', '').sub(/(p-?\d+)/, ' \1').split.join('-')
     end
   end
 
@@ -178,33 +170,29 @@ def bundler_version_escape_valve!
 
   private
   def fetch_bundler
-    instrument 'fetch_bundler' do
-      return true if Dir.exists?(bundler_path)
-
-      topic("Installing bundler #{@version}")
-      bundler_version_escape_valve!
-
-      # Install directory structure (as of Bundler 2.1.4):
-      # - cache
-      # - bin
-      # - gems
-      # - specifications
-      # - build_info
-      # - extensions
-      # - doc
-      FileUtils.mkdir_p(bundler_path)
-      Dir.chdir(bundler_path) do
-        @fetcher.fetch_untar(@bundler_tar)
-      end
-      Dir["bin/*"].each {|path| `chmod 755 #{path}` }
+    return true if Dir.exists?(bundler_path)
+
+    topic("Installing bundler #{@version}")
+    bundler_version_escape_valve!
+
+    # Install directory structure (as of Bundler 2.1.4):
+    # - cache
+    # - bin
+    # - gems
+    # - specifications
+    # - build_info
+    # - extensions
+    # - doc
+    FileUtils.mkdir_p(bundler_path)
+    Dir.chdir(bundler_path) do
+      @fetcher.fetch_untar(@bundler_tar)
     end
+    Dir["bin/*"].each {|path| `chmod 755 #{path}` }
   end
 
   def parse_gemfile_lock
-    instrument 'parse_bundle' do
-      gemfile_contents = File.read(@gemfile_lock_path)
-      Bundler::LockfileParser.new(gemfile_contents)
-    end
+    gemfile_contents = File.read(@gemfile_lock_path)
+    Bundler::LockfileParser.new(gemfile_contents)
   end
 
   def major_bundler_version

lib/language_pack/helpers/rake_runner.rb

@@ -81,16 +81,10 @@ def rakefile_can_load?
     @rakefile_can_load
   end
 
-  def instrument(*args, &block)
-    LanguagePack::Instrument.instrument(*args, &block)
-  end
-
   def load_rake_tasks(options = {})
-    instrument "ruby.rake_task_defined" do
-      @rake_tasks        ||= RakeTask.new("-P --trace").invoke(options.merge(quiet: true)).output
-      @rakefile_can_load ||= $?.success?
-      @rake_tasks
-    end
+    @rake_tasks        ||= RakeTask.new("-P --trace").invoke(options.merge(quiet: true)).output
+    @rakefile_can_load ||= $?.success?
+    @rake_tasks
   end
 
   def load_rake_tasks!(options = {}, raise_on_fail = false)