Don't load eyaml when SECRET_KEY_BASE_DUMMY env var is set (#43)

* Do not try to load secrets or credentials

when SECRET_KEY_BASE_DUMMY env var is set

* Bump version to 0.4.4

* Update readme

README.md

@@ -114,6 +114,9 @@ Instead of needing a private key locally, you can provide it to EYAML by setting
 
 If you put your rails master key encrypted in the eyaml file, make sure you don't have another `master.key` file somewhere, since that can interfere.
 
+When setting the SECRET_KEY_BASE_DUMMY environment variable, the secrets/credentials loading will be skipped.
+This can be handy to for example do an asset precompilation step in production where you don't need any secrets/credentials.
+
 ### Example setup
 
 To add encryption + credentials to a rails project do the following things:

lib/eyaml/railtie.rb

@@ -12,34 +12,37 @@ class ConflictError < StandardError
       end
 
       config.before_configuration do
-        if File.exist?(Rails.root.join("config", "master.key"))
-          raise ConflictError, "A config/master.key has been found. The rails credentials lookup conflicts with eyaml. Please remove rails credentials management by removing the master.key file to keep using eyaml."
-        end
-        secret_files_present = Dir.glob(auth_files(:secrets)).any?
-        credential_files_present = Dir.glob(auth_files(:credentials)).any?
+        unless ENV.fetch("SECRET_KEY_BASE_DUMMY", false)
+          # Allow rails to run without loading the credentials
+          if File.exist?(Rails.root.join("config", "master.key"))
+            raise ConflictError, "A config/master.key has been found. The rails credentials lookup conflicts with eyaml. Please remove rails credentials management by removing the master.key file to keep using eyaml."
+          end
+          secret_files_present = Dir.glob(auth_files(:secrets)).any?
+          credential_files_present = Dir.glob(auth_files(:credentials)).any?
 
-        secrets_or_credentials = if Rails.version >= "7.2"
-          :credentials
-        else
-          if credential_files_present
+          secrets_or_credentials = if Rails.version >= "7.2"
             :credentials
-          elsif secret_files_present
-            :secrets
+          else
+            if credential_files_present
+              :credentials
+            elsif secret_files_present
+              :secrets
+            end
           end
-        end
 
-        auth_files(secrets_or_credentials).each do |file|
-          next unless valid?(file)
+          auth_files(secrets_or_credentials).each do |file|
+            next unless valid?(file)
 
-          # If private_key is nil (i.e. when $EJSON_PRIVATE_KEY is not set), EYAML will search
-          # for a public/private key in the key directory (either $EJSON_KEYDIR, if set, or /opt/ejson/keys)
-          cipherdata = YAML.load_file(file)
-          secrets = EYAML.decrypt(cipherdata, private_key: ENV[PRIVATE_KEY_ENV_VAR])
-            .except("_public_key")
-          secrets = EYAML::Util.with_deep_deundescored_keys(secrets)
-            .deep_symbolize_keys
+            # If private_key is nil (i.e. when $EJSON_PRIVATE_KEY is not set), EYAML will search
+            # for a public/private key in the key directory (either $EJSON_KEYDIR, if set, or /opt/ejson/keys)
+            cipherdata = YAML.load_file(file)
+            secrets = EYAML.decrypt(cipherdata, private_key: ENV[PRIVATE_KEY_ENV_VAR])
+              .except("_public_key")
+            secrets = EYAML::Util.with_deep_deundescored_keys(secrets)
+              .deep_symbolize_keys
 
-          break Rails.application.send(secrets_or_credentials).deep_merge!(secrets)
+            break Rails.application.send(secrets_or_credentials).deep_merge!(secrets)
+          end
         end
       end
 

lib/eyaml/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module EYAML
-  VERSION = "0.4.3"
+  VERSION = "0.4.4"
 end

spec/eyaml/railtie_spec.rb

@@ -16,6 +16,8 @@
     let(:credentials) { credentials_class.new }
 
     before(:each) do
+      ENV.delete("SECRET_KEY_BASE_DUMMY")
+
       FakeFS::FileSystem.clone(fixtures_root)
 
       supported_extensions.each do |ext|
@@ -43,6 +45,12 @@
         end
       end
 
+      it "does not try to load credentials when SECRET_KEY_BASE_DUMMY env var is set" do
+        ENV["SECRET_KEY_BASE_DUMMY"] = "1"
+        expect { run_load_hooks }.not_to raise_error
+        expect(credentials).to(be_empty)
+      end
+
       it "raises when a master.key file is present" do
         run_load_hooks
         expect(credentials).to(include(:secret))
@@ -147,6 +155,8 @@
     let(:secrets) { secrets_class.new }
 
     before(:each) do
+      ENV.delete("SECRET_KEY_BASE_DUMMY")
+
       FakeFS::FileSystem.clone(fixtures_root)
 
       supported_extensions.each do |ext|
@@ -168,6 +178,12 @@
         allow_rails.to(receive_message_chain("application.secrets").and_return(secrets))
       end
 
+      it "does not try to load secrets when SECRET_KEY_BASE_DUMMY env var is set" do
+        ENV["SECRET_KEY_BASE_DUMMY"] = "1"
+        expect { run_load_hooks }.not_to raise_error
+        expect(secrets).to(be_empty)
+      end
+
       it "merges secrets into application secrets" do
         run_load_hooks
         expect(secrets).to(include(:secret))