Store Let's Encrypt private key in settings

Storing this key in secrets.yml was a bad idea,
it would require users using HA setups to manually
replicate secrets across nodes during update,
it also needed support from omnibus package

* Revert "Generate Let's Encrypt private key"
  This reverts commit 444959bfa0b79e827a2a1a7a314acac19390f976.

* Add Let's Encrypt private key to settings
  as encrypted attribute

* Generate Let's Encrypt private key
  in database migration

2 files changed, 49 insertions, 0 deletions

diff --git a/db/migrate/20190516151857_add_lets_encrypt_private_key_to_application_settings.rb b/db/migrate/20190516151857_add_lets_encrypt_private_key_to_application_settings.rb
new file mode 100644
index 00000000000..e1d3cca48d6
--- /dev/null
+++ b/db/migrate/20190516151857_add_lets_encrypt_private_key_to_application_settings.rb
@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class AddLetsEncryptPrivateKeyToApplicationSettings < ActiveRecord::Migration[5.1]
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  def change
+    add_column :application_settings, :encrypted_lets_encrypt_private_key, :text
+    add_column :application_settings, :encrypted_lets_encrypt_private_key_iv, :text
+  end
+end
diff --git a/db/migrate/20190524062810_generate_lets_encrypt_private_key.rb b/db/migrate/20190524062810_generate_lets_encrypt_private_key.rb
new file mode 100644
index 00000000000..21d7049b998
--- /dev/null
+++ b/db/migrate/20190524062810_generate_lets_encrypt_private_key.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class GenerateLetsEncryptPrivateKey < ActiveRecord::Migration[5.1]
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  class ApplicationSetting < ActiveRecord::Base
+    self.table_name = 'application_settings'
+
+    attr_encrypted :lets_encrypt_private_key,
+                   mode: :per_attribute_iv,
+                   key: Settings.attr_encrypted_db_key_base_truncated,
+                   algorithm: 'aes-256-gcm',
+                   encode: true
+  end
+
+  def up
+    ApplicationSetting.reset_column_information
+
+    private_key = OpenSSL::PKey::RSA.new(4096).to_pem
+    ApplicationSetting.find_each do |setting|
+      setting.update!(lets_encrypt_private_key: private_key)
+    end
+  end
+
+  def down
+  end
+end