Use Rails multi DB

.gitignore

@@ -6,3 +6,4 @@ gemfiles/*.lock
 log/*
 .*.sw[a-z]
 /bin/test_local
+/test/config/database.local.yml

.travis.yml

@@ -10,7 +10,6 @@ rvm:
   - 2.6.6
   - 2.7.1
 gemfile:
-  - gemfiles/rails52.gemfile
   - gemfiles/rails60.gemfile
 script:
   - "bin/test"

Appraisals

@@ -1,8 +1,3 @@
-appraise "rails52" do
-  gem 'activerecord', '~> 5.2.0'
-  gem 'mysql2', '>= 0.4.4', "< 0.6.0"
-end
-
 appraise "rails60" do
   gem 'activerecord', '~> 6.0.0'
 end

CODE_OF_CONDUCT.md

@@ -1,49 +1,74 @@
-# Contributor Code of Conduct
+# Contributor Covenant Code of Conduct
 
-As contributors and maintainers of this project, and in the interest of
-fostering an open and welcoming community, we pledge to respect all people who
-contribute through reporting issues, posting feature requests, updating
-documentation, submitting pull requests or patches, and other activities.
+## Our Pledge
 
-We are committed to making participation in this project a harassment-free
-experience for everyone, regardless of level of experience, gender, gender
-identity and expression, sexual orientation, disability, personal appearance,
-body size, race, ethnicity, age, religion, or nationality.
+In the interest of fostering an open and welcoming environment, we as
+contributors and maintainers pledge to making participation in our project and
+our community a harassment-free experience for everyone, regardless of age, body
+size, disability, ethnicity, gender identity and expression, level of experience,
+nationality, personal appearance, race, religion, or sexual identity and
+orientation.
+
+## Our Standards
+
+Examples of behavior that contributes to creating a positive environment
+include:
+
+* Using welcoming and inclusive language
+* Being respectful of differing viewpoints and experiences
+* Gracefully accepting constructive criticism
+* Focusing on what is best for the community
+* Showing empathy towards other community members
 
 Examples of unacceptable behavior by participants include:
 
-* The use of sexualized language or imagery
-* Personal attacks
-* Trolling or insulting/derogatory comments
+* The use of sexualized language or imagery and unwelcome sexual attention or
+advances
+* Trolling, insulting/derogatory comments, and personal or political attacks
 * Public or private harassment
-* Publishing other's private information, such as physical or electronic
-  addresses, without explicit permission
-* Other unethical or unprofessional conduct
+* Publishing others' private information, such as a physical or electronic
+  address, without explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Our Responsibilities
+
+Project maintainers are responsible for clarifying the standards of acceptable
+behavior and are expected to take appropriate and fair corrective action in
+response to any instances of unacceptable behavior.
 
 Project maintainers have the right and responsibility to remove, edit, or
 reject comments, commits, code, wiki edits, issues, and other contributions
 that are not aligned to this Code of Conduct, or to ban temporarily or
 permanently any contributor for other behaviors that they deem inappropriate,
 threatening, offensive, or harmful.
 
-By adopting this Code of Conduct, project maintainers commit themselves to
-fairly and consistently applying these principles to every aspect of managing
-this project. Project maintainers who do not follow or enforce the Code of
-Conduct may be permanently removed from the project team.
+## Scope
+
+This Code of Conduct applies both within project spaces and in public spaces
+when an individual is representing the project or its community. Examples of
+representing a project or community include using an official project e-mail
+address, posting via an official social media account, or acting as an appointed
+representative at an online or offline event. Representation of a project may be
+further defined and clarified by project maintainers.
 
-This code of conduct applies both within project spaces and in public spaces
-when an individual is representing the project or its community.
+## Enforcement
 
 Instances of abusive, harassing, or otherwise unacceptable behavior may be
-reported by contacting a project maintainer at tsukasa.oishi@gmail.com. All
+reported by contacting the project team at tsukasa.oishi@gmail.com. All
 complaints will be reviewed and investigated and will result in a response that
-is deemed necessary and appropriate to the circumstances. Maintainers are
-obligated to maintain confidentiality with regard to the reporter of an
-incident.
+is deemed necessary and appropriate to the circumstances. The project team is
+obligated to maintain confidentiality with regard to the reporter of an incident.
+Further details of specific enforcement policies may be posted separately.
+
+Project maintainers who do not follow or enforce the Code of Conduct in good
+faith may face temporary or permanent repercussions as determined by other
+members of the project's leadership.
+
+## Attribution
 
-This Code of Conduct is adapted from the [Contributor Covenant][homepage],
-version 1.3.0, available at
-[http://contributor-covenant.org/version/1/3/0/][version]
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4,
+available at [https://contributor-covenant.org/version/1/4][version]
 
-[homepage]: http://contributor-covenant.org
-[version]: http://contributor-covenant.org/version/1/3/0/
+[homepage]: https://contributor-covenant.org
+[version]: https://contributor-covenant.org/version/1/4/

README.md

@@ -36,9 +36,6 @@ When what happens one of the replicas is unreachable for any reason, FreshConnec
 Removing a trouble replica from a cluster is a work of the load balancer.  
 FreshConnection expects the load balancer to work during three retries.  
 
-If you would like access to multi replica servers without a load balancer, you should use [EbisuConnection](https://github.com/tsukasaoishi/ebisu_connection).  
-EbisuConnection has functions of load balancer.
-
 ## Usage
 ### Access to the DB Replica
 Read queries are automatically connected to the DB replica.
@@ -78,12 +75,8 @@ old_article.destroy
 
 ## ActiveRecord Versions Supported
 
-- FreshConnection supports ActiveRecord version 5.2 or later.
-- If you are using Rails 5.1, you can use FreshConnection version 3.0.3 or before.
-
-### Not Support Multiple Database
-I haven't tested it in an environment using MultipleDB in Rails 6.
-I plan to enable use with MultipleDB in FreshConnection version 4.0 or later.
+- FreshConnection supports ActiveRecord version 6.0 or later.
+- If you are using Rails 5.2, you can use FreshConnection version 3.1.0 or before.
 
 ## Databases Supported
 FreshConnection currently supports MySQL and PostgreSQL.
@@ -108,98 +101,10 @@ $ gem install fresh_connection
 ```
 
 ## Configuration
+FreshConnection uses [ActiveRecord Multiple Databases](https://guides.rubyonrails.org/active_record_multiple_databases.html) for connection management.  
+See the Rails documentation for how to set up a read replica.
 
-The FreshConnection database replica is configured within the standard Rails
-database configuration file, `config/database.yml`, using a `replica:` stanza.
-
-Below is a sample such configuration file.
-
-### `config/database.yml`
-
-```yaml
-default: &default
-  adapter: mysql2
-  encoding: utf8
-  pool: <%%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
-  username: root
-  password:
-
-production:
-  <<: *default
-  database: blog_production
-  username: master_db_user
-  password: <%= ENV['MASTER_DATABASE_PASSWORD'] %>
-  host: master_db
-
-  replica:
-    username: replica_db_user
-    password: <%= ENV['REPLICA_DATABASE_PASSWORD'] %>
-    host: replica_db
-```
-
-`replica` is the configuration used for connecting read-only queries to the database replica.  All other connections will use the database master settings.
-
-
-### Multiple DB Replicas
-If you want to use multiple configured DB replicas, the configuration can contain multiple `replica` stanzas in the configuration file `config/database.yml`.
-
-For example:
-
-```yaml
-default: &default
-  adapter: mysql2
-  encoding: utf8
-  pool: <%%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
-  username: root
-  password:
-
-production:
-  <<: *default
-  database: blog_production
-  username: master_db_user
-  password: <%= ENV['MASTER_DATABASE_PASSWORD'] %>
-  host: master_db
-
-  replica:
-    username: replica_db_user
-    password: <%= ENV['REPLICA_DATABASE_PASSWORD'] %>
-    host: replica_db
-
-  admin_replica:
-    username: admin_replica_db_user
-    password: <%= ENV['ADMIN_REPLICA_DATABASE_PASSWORD'] %>
-    host: admin_replica_db
-```
-
-The custom replica stanza can then be applied as an argument to the `establish_fresh_connection` method in the models that should use it.  For example:
-
-```ruby
-class AdminUser < ActiveRecord::Base
-  establish_fresh_connection :admin_replica
-end
-```
-
-The child (sub) classes of the configured model will inherit the same access as the parent class.  Example:
-
-```ruby
-class AdminBase < ActiveRecord::Base
-  establish_fresh_connection :admin_replica
-end
-
-class AdminUser < AdminBase
-end
-
-class Benefit < AdminBase
-end
-
-class Customer < ActiveRecord::Base
-end
-```
-
-The `AdminUser` and `Benefit` models will access the database configured for the `admin_replica` group.
-
-The `Customer` model will use the default connections: read-only queries will connect to the standard DB replica, and state-changing queries will connect to the DB master.
-
+`establish_fresh_connection` used by FreshConnection has been discontinued.
 
 ### Replica Configuration With Environment Variables
 

bin/console

@@ -11,4 +11,4 @@ require "fresh_connection"
 # Pry.start
 
 require "irb"
-IRB.start
+IRB.start(__FILE__)

bin/setup

@@ -3,8 +3,6 @@ set -euo pipefail
 IFS=$'\n\t'
 set -vx
 
-bundle config set path '.bundle'
 bundle install
-bundle exec appraisal install
 
 # Do any other automated setup that you need to do here

bin/test

@@ -4,21 +4,10 @@ IFS=$'\n\t'
 
 set -vx
 
-if [ -v DATABASE_URL ]; then
-  echo "[specified config]"
+echo "[mysql]"
+FC_TEST_ADAPTER=mysql \
   bundle exec rake test
-else
-  echo "[mysql]"
-  DATABASE_URL="mysql2://root@localhost/fresh_connection_test_master" \
-    DATABASE_REPLICA1_URL="mysql2://root@localhost/fresh_connection_test_replica1" \
-    DATABASE_REPLICA2_URL="mysql2://root@localhost/fresh_connection_test_replica2" \
-    DATABASE_FAKE_REPLICA_URL="mysql2://root@localhost/fresh_connection_test_master" \
-    bundle exec rake test
 
-  echo "[postgresql]"
-  DATABASE_URL="postgresql://localhost/fresh_connection_test_master" \
-    DATABASE_REPLICA1_URL="postgresql://localhost/fresh_connection_test_replica1" \
-    DATABASE_REPLICA2_URL="postgresql://localhost/fresh_connection_test_replica2" \
-    DATABASE_FAKE_REPLICA_URL="postgresql://localhost/fresh_connection_test_master" \
-    bundle exec rake test
-fi
+echo "[postgresql]"
+FC_TEST_ADAPTER=psgr \
+  bundle exec rake test

fresh_connection.gemspec

@@ -1,7 +1,4 @@
-# coding: utf-8
-lib = File.expand_path('../lib', __FILE__)
-$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
-require 'fresh_connection/version'
+require_relative 'lib/fresh_connection/version'
 
 Gem::Specification.new do |spec|
   spec.name          = "fresh_connection"
@@ -12,14 +9,20 @@ Gem::Specification.new do |spec|
   spec.summary       = %q{FreshConnection supports connections with configured replica servers.}
   spec.description   = %q{https://github.com/tsukasaoishi/fresh_connection}
   spec.homepage      = "https://github.com/tsukasaoishi/fresh_connection"
-  spec.license       = "MIT"
+  spec.required_ruby_version = Gem::Requirement.new(">= 2.4.0")
 
-  spec.files         = `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features)/}) }
+  spec.metadata["homepage_uri"] = spec.homepage
+
+  # Specify which files should be added to the gem when it is released.
+  # The `git ls-files -z` loads the files in the RubyGem that have been added into git.
+  spec.files         = Dir.chdir(File.expand_path('..', __FILE__)) do
+    `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features)/}) }
+  end
   spec.bindir        = "exe"
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
-  spec.add_dependency 'activerecord', '>= 5.2.0', '< 6.1'
+  spec.add_dependency 'activerecord', '>= 6.0.0', '< 6.1'
 
   spec.add_development_dependency 'mysql2', '>= 0.4.4'
   spec.add_development_dependency 'pg', '>= 0.18', '< 2.0'

lib/fresh_connection/access_control.rb

@@ -7,11 +7,11 @@ class << self
       private_constant :RETRY_LIMIT
 
       def manage_access(model:, replica_access:, &block)
-        return force_master_access(&block) if model.master_db_only?
+        return force_master_access(model: model, &block) if model.master_db_only?
 
         retry_count = 0
         begin
-          access(replica_access, &block)
+          access(replica_access, model: model, &block)
         rescue *catch_exceptions
           if recovery?(model.replica_spec_name)
             retry_count += 1
@@ -28,21 +28,26 @@ def replica_access?
 
       private
 
-      def force_master_access(&block)
-        switch_to(:master, &block)
+      def force_master_access(model: , &block)
+        switch_to(:master, model: model, &block)
       end
 
-      def access(replica_access, &block)
+      def access(replica_access, model: , &block)
         return yield if access_db
 
         db = replica_access ? :replica : :master
-        switch_to(db, &block)
+        switch_to(db, model: model, &block)
       end
 
-      def switch_to(new_db)
+      def switch_to(new_db, model:)
         old_db = access_db
         access_to(new_db)
-        yield
+
+        if replica_access?
+          model.connected_to(role: model.reading_role) { yield }
+        else
+          yield
+        end
       ensure
         access_to(old_db)
       end