Vendor libpq5.12.1 into Slugs - Heroku 18 only

CHANGELOG.md

@@ -1,5 +1,6 @@
 ## v207 (unreleased)
 
+* Vendor in libpq 5.12.1 for Heroku-18 (https://github.com/heroku/heroku-buildpack-ruby/pull/936)
 * Remove possibilities of false exceptions being raised by removing `BUNDLED WITH` from the `Gemfile.lock` (https://github.com/heroku/heroku-buildpack-ruby/pull/928)
 
 ## v206 (10/15/2019)

changelogs/v207/vendor_libpq.md

@@ -0,0 +1,15 @@
+## Postgresql client library libpq version 5.12.1 now vendored into Ruby applications on Heroku-18
+
+Ruby applications deploying to Heroku-18 will get a vendored version of the libpq client library version 5.12.1 starting today. For more information about the reasons for this change and the possible effects see:
+
+https://devcenter.heroku.com/articles/libpq-5-12-1-breaking-connection-behavior
+
+If your application breaks due to this change you can rollback to your last build. You can also temporarially opt out of this behavior by setting:
+
+```
+$ heroku config:set HEROKU_SKIP_LIBPQ12=1
+```
+
+In the future libpq 5.12 will be the default on the platform and you will not be able to opt-out of the library. For more information see:
+
+https://devcenter.heroku.com/articles/libpq-5-12-1-breaking-connection-behavior

hatchet.json

@@ -30,7 +30,8 @@
     "sharpstone/jruby-minimal",
     "sharpstone/empty-procfile",
     "sharpstone/bad_ruby_version",
-    "sharpstone/activerecord41_scaffold"
+    "sharpstone/activerecord41_scaffold",
+    "sharpstone/libpq_connection_error"
   ],
   "jruby": [
     "sharpstone/jruby_naether"

hatchet.lock

@@ -111,6 +111,8 @@
   - 7cae0aae424c2028b81b5d37ee24d42db8e545b9
 - - "./repos/ruby/jruby-minimal"
   - f79860bc2866449fe065484f1542aaadd3f7cfd2
+- - "./repos/ruby/libpq_connection_error"
+  - c211c245f09d8335a520cd7a0b5360897d4988eb
 - - "./repos/ruby/mri_187"
   - 43cecfacbedda64f09310a4408ce73c5dc3a9c44
 - - "./repos/ruby/mri_193_p547"

lib/language_pack/metadata.rb

@@ -35,6 +35,15 @@ def touch(key)
     write(key, "true")
   end
 
+  def fetch(key)
+    return read(key) if exists?(key)
+
+    value = yield
+
+    write(key, value.to_s)
+    return value
+  end
+
   def save
     @cache ? @cache.add(FOLDER) : false
   end

lib/language_pack/ruby.rb

@@ -99,6 +99,7 @@ def compile
       setup_export
       setup_profiled
       allow_git do
+        vendor_libpq
         install_bundler_in_app
         build_bundler("development:test")
         post_bundler
@@ -117,6 +118,55 @@ def compile
     raise e
   end
 
+  def vendor_libpq
+    # Check for existing libraries
+    return unless File.exist?("/usr/lib/x86_64-linux-gnu/libpq.so.5.11")
+    return unless ENV['STACK'] == 'heroku-18'
+
+    topic("Vendoring libpq 5.12.1")
+
+    @metadata.fetch("vendor_libpq12") do
+      warn(<<~EOF)
+        Replacing libpq with version libpq 5.12.1
+
+        This version includes a bug fix that can cause an exception
+        on boot for applications with incorrectly configured connection
+        values. For more information see:
+
+          https://devcenter.heroku.com/articles/libpq-5-12-1-breaking-connection-behavior
+
+        If your application breaks you can rollback to your last build.
+        You can also temporarially opt out of this behavior by setting:
+
+        ```
+        $ heroku config:set HEROKU_SKIP_LIBPQ12=1
+        ```
+
+        In the future libpq 5.12 will be the default on the platform and
+        you will not be able to opt-out of the library. For more information see:
+
+          https://devcenter.heroku.com/articles/libpq-5-12-1-breaking-connection-behavior
+      EOF
+
+      "true" # Set future cache value
+    end
+
+    Dir.chdir("vendor") do
+      @fetchers[:mri].fetch("libpq5_12.1-1.deb")
+      run!("dpkg -x libpq5_12.1-1.deb .")
+      run!("rm libpq5_12.1-1.deb")
+
+      load_libpq_12_unless_env_var = <<~EOF
+        if [ "$HEROKU_SKIP_LIBPQ12" == "" ]; then
+          export LD_LIBRARY_PATH="$HOME/vendor/usr/lib/x86_64-linux-gnu/:$LD_LIBRARY_PATH"
+        fi
+      EOF
+      add_to_export load_libpq_12_unless_env_var
+      add_to_profiled load_libpq_12_unless_env_var
+      ENV["LD_LIBRARY_PATH"] = Dir.pwd + "/usr/lib/x86_64-linux-gnu:#{ENV["LD_LIBRARY_PATH"]}"
+    end
+  end
+
   def cleanup
   end
 

spec/hatchet/ruby_spec.rb

@@ -1,6 +1,24 @@
 require_relative '../spec_helper'
 
 describe "Ruby apps" do
+  describe "vendoring libpq" do
+    it "works on heroku-16" do
+      skip "Blocked on getting heroku-16 docker example to work https://github.com/schneems/libpq_heroku_16_reproduction/tree/schneems/manually-download-install"
+
+      Hatchet::Runner.new("libpq_connection_error", stack: "heroku-16").deploy do |app|
+        out = app.run("ruby reproduce_error.rb")
+        expect(out).to match(%Q{invalid integer value "15s"})
+      end
+    end
+
+    it "works on heroku-18" do
+      Hatchet::Runner.new("libpq_connection_error", stack: "heroku-18").deploy do |app|
+        out = app.run("ruby reproduce_error.rb")
+        expect(out).to match(%Q{invalid integer value "15s"})
+      end
+    end
+  end
+
   describe "running Ruby from outside the default dir" do
     it "works" do
       Hatchet::Runner.new('cd_ruby', stack: DEFAULT_STACK).deploy do |app|