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張 旭

A Guide to Testing Rails Applications - Ruby on Rails Guides - 0 views

guides.rubyonrails.org/testing.html

rails test ruby unit

shared by 張 旭 on 08 May 16 - Cached
  • Rails tests can also simulate browser requests and thus you can test your application's response without having to test it through your browser.
  • your tests will need a database to interact with as well.
  • By default, every Rails application has three environments: development, test, and production
  • ...25 more annotations...
  • models directory is meant to hold tests for your models
  • controllers directory is meant to hold tests for your controllers
  • integration directory is meant to hold tests that involve any number of controllers interacting
  • Fixtures are a way of organizing test data; they reside in the fixtures folder
  • The test_helper.rb file holds the default configuration for your tests
  • Fixtures allow you to populate your testing database with predefined data before your tests run
  • Fixtures are database independent written in YAML.
  • one file per model.
  • Each fixture is given a name followed by an indented list of colon-separated key/value pairs.
  • Keys which resemble YAML keywords such as 'yes' and 'no' are quoted so that the YAML Parser correctly interprets them.
  • define a reference node between two different fixtures.
  • ERB allows you to embed Ruby code within templates
  • The YAML fixture format is pre-processed with ERB when Rails loads fixtures.
  • Rails by default automatically loads all fixtures from the test/fixtures folder for your models and controllers test.
  • Fixtures are instances of Active Record.
  • access the object directly
  • test_helper.rb specifies the default configuration to run our tests. This is included with all the tests, so any methods added to this file are available to all your tests.
  • test with method names prefixed with test_.
  • An assertion is a line of code that evaluates an object (or expression) for expected results.
  • bin/rake db:test:prepare
  • Every test contains one or more assertions. Only when all the assertions are successful will the test pass.
  • rake test command
  • run a particular test method from the test case by running the test and providing the test method name.
  • The . (dot) above indicates a passing test. When a test fails you see an F; when a test throws an error you see an E in its place.
  • we first wrote a test which fails for a desired functionality, then we wrote some code which adds the functionality and finally we ensured that our test passes. This approach to software development is referred to as Test-Driven Development (TDD).
張 旭

Larry Cai - Travis CI会替代Jenkins吗？ - 0 views

www.larrycaiyu.com/...travis-ci-is-evolution.html

travis jenkins system CI test

shared by 張 旭 on 06 Sep 16 - No Cached
  • Jenkins能够让通过主从模式（master/slave）多台机器一起构建。
  • 一切都可以在Web界面中运行。
  • 当然你可有使用虚拟机的技术vagrant/virtualbox，参见使用vagrant+jenkins来管理虚拟机的技巧。可以工作，不太优雅。因为它不是原生的，有点复杂。
    • 張 旭
      張 旭 on 06 Sep 16
       
      現在應該有 Docker Container 跑測試的整合了。
  • ...5 more annotations...
  • 在CI服务器创建任务（记住：这些配置文件不是有版本控制的）
  • 构建的配置文件直接就和源码放在一起，而且配置文件使用DSL写的，可读性更高。
  • 要求在两个Ruby环境中运行，它就帮我做到了，我并不关心它是怎么切换的
  • Travis CI使用的Ruby语言，一开始考虑的就是分布式构建
  • 它的虚拟机部分只是Vagrant/Virtualbox，但是这一块是很容易迁移到其他的技术的。
    • 張 旭
      張 旭 on 06 Sep 16
       
      Docker! Docker! Docker!
張 旭

Slimming Down Your Models and Controllers with Concerns, Service Objects, and Tableless... - 1 views

www.viget.com/...wn-your-models-and-controllers

rails development model pattern controller

shared by 張 旭 on 29 Nov 16 - No Cached
  • The single responsibility principle asserts that every class should have exactly one responsibility. In other words, each class should be concerned about one unique nugget of functionality
  • fat models are a little better than fat controllers
  • when every bit of functionality has been encapsulated into its own object, you find yourself repeating code a lot less.
  • ...2 more annotations...
  • objects with a single responsibility can easily be unit tested
  • a vanilla Rails 4 app directory contains models, views, controllers, and helpers does not mean you are restricted to those four domains.
張 旭

ssl - How to get .pem file from .key and .crt files? - Stack Overflow - 0 views

stackoverflow.com/...em-file-from-key-and-crt-files

https security server nginx apache ssl key

shared by 張 旭 on 22 Feb 17 - No Cached
  • openssl rsa -in server.key -text > private.pem openssl x509 -inform PEM -in server.crt > public.pem
  • A pem file contains the certificate and the private key.
張 旭

Rails Routing from the Outside In - Ruby on Rails Guides - 0 views

guides.rubyonrails.org/routing.html

rails router path url namespace

shared by 張 旭 on 09 Mar 14 - Cached
  • Resource routing allows you to quickly declare all of the common routes for a given resourceful controller.
  • Rails would dispatch that request to the destroy method on the photos controller with { id: '17' } in params.
  • a resourceful route provides a mapping between HTTP verbs and URLs to controller actions.
  • ...86 more annotations...
  • each action also maps to particular CRUD operations in a database
  • resource :photo and resources :photos creates both singular and plural routes that map to the same controller (PhotosController).
  • One way to avoid deep nesting (as recommended above) is to generate the collection actions scoped under the parent, so as to get a sense of the hierarchy, but to not nest the member actions.
  • to only build routes with the minimal amount of information to uniquely identify the resource
  • The shallow method of the DSL creates a scope inside of which every nesting is shallow
  • These concerns can be used in resources to avoid code duplication and share behavior across routes
  • add a member route, just add a member block into the resource block
  • You can leave out the :on option, this will create the same member route except that the resource id value will be available in params[:photo_id] instead of params[:id].
  • Singular Resources
  • use a singular resource to map /profile (rather than /profile/:id) to the show action
  • Passing a String to get will expect a controller#action format
  • workaround
  • organize groups of controllers under a namespace
  • route /articles (without the prefix /admin) to Admin::ArticlesController
  • route /admin/articles to ArticlesController (without the Admin:: module prefix)
  • Nested routes allow you to capture this relationship in your routing.
  • helpers take an instance of Magazine as the first parameter (magazine_ads_url(@magazine)).
  • Resources should never be nested more than 1 level deep.
  • via the :shallow option
  • a balance between descriptive routes and deep nesting
  • :shallow_path prefixes member paths with the specified parameter
  • Routing Concerns allows you to declare common routes that can be reused inside other resources and routes
  • Rails can also create paths and URLs from an array of parameters.
  • use url_for with a set of objects
  • In helpers like link_to, you can specify just the object in place of the full url_for call
  • insert the action name as the first element of the array
  • This will recognize /photos/1/preview with GET, and route to the preview action of PhotosController, with the resource id value passed in params[:id]. It will also create the preview_photo_url and preview_photo_path helpers.
  • pass :on to a route, eliminating the block:
  • Collection Routes
  • This will enable Rails to recognize paths such as /photos/search with GET, and route to the search action of PhotosController. It will also create the search_photos_url and search_photos_path route helpers.
  • simple routing makes it very easy to map legacy URLs to new Rails actions
  • add an alternate new action using the :on shortcut
  • When you set up a regular route, you supply a series of symbols that Rails maps to parts of an incoming HTTP request.
  • :controller maps to the name of a controller in your application
  • :action maps to the name of an action within that controller
  • optional parameters, denoted by parentheses
  • This route will also route the incoming request of /photos to PhotosController#index, since :action and :id are
  • use a constraint on :controller that matches the namespace you require
  • dynamic segments don't accept dots
  • The params will also include any parameters from the query string
  • :defaults option.
  • set params[:format] to "jpg"
  • cannot override defaults via query parameters
  • specify a name for any route using the :as option
  • create logout_path and logout_url as named helpers in your application.
  • Inside the show action of UsersController, params[:username] will contain the username for the user.
  • should use the get, post, put, patch and delete methods to constrain a route to a particular verb.
  • use the match method with the :via option to match multiple verbs at once
  • Routing both GET and POST requests to a single action has security implications
  • 'GET' in Rails won't check for CSRF token. You should never write to the database from 'GET' requests
  • use the :constraints option to enforce a format for a dynamic segment
  • constraints
  • don't need to use anchors
  • Request-Based Constraints
  • the same name as the hash key and then compare the return value with the hash value.
  • constraint values should match the corresponding Request object method return type
    • 張 旭
      張 旭 on 11 Apr 16
       
      應該就是檢查來源的 request， 如果是某個特定的 request 來訪問的，就通過。
  • blacklist
    • 張 旭
      張 旭 on 11 Apr 16
       
      這裡有點複雜 ...
  • redirect helper
  • reuse dynamic segments from the match in the path to redirect
  • this redirection is a 301 "Moved Permanently" redirect.
  • root method
  • put the root route at the top of the file
  • The root route only routes GET requests to the action.
  • root inside namespaces and scopes
  • For namespaced controllers you can use the directory notation
  • Only the directory notation is supported
  • use the :constraints option to specify a required format on the implicit id
  • specify a single constraint to apply to a number of routes by using the block
  • non-resourceful routes
  • :id parameter doesn't accept dots
  • :as option lets you override the normal naming for the named route helpers
  • use the :as option to prefix the named route helpers that Rails generates for a rout
  • prevent name collisions
  • prefix routes with a named parameter
  • This will provide you with URLs such as /bob/articles/1 and will allow you to reference the username part of the path as params[:username] in controllers, helpers and views
  • :only option
  • :except option
  • generate only the routes that you actually need can cut down on memory use and speed up the routing process.
  • alter path names
  • http://localhost:3000/rails/info/routes
  • rake routes
  • setting the CONTROLLER environment variable
  • Routes should be included in your testing strategy
  • assert_generates assert_recognizes assert_routing
張 旭

javascript - How do I "think in AngularJS" if I have a jQuery background? - Stack Overflow - 0 views

stackoverflow.com/...-if-i-have-a-jquery-background

jquery javascript angular programming architecture development google angularjs web

shared by 張 旭 on 02 Oct 13 - No Cached
  • in AngularJS, we have a separate model layer that we can manage in any way we want, completely independently from the view.
  • keep your concerns separate
  • do DOM manipulation and augment your view with directives
  • ...34 more annotations...
  • DI means that you can declare components very freely and then from any other component, just ask for an instance of it and it will be granted
  • do test-driven development iteratively in AngularJS!
  • only do DOM manipulation in a directive
  • with ngClass we can dynamically update the class;
  • ngBind allows two-way data binding;
  • ngShow and ngHide programmatically show or hide an element;
  • The less DOM manipulation, the easier directives are to test, the easier they are to style, the easier they are to change in the future, and the more re-usable and distributable they are.
  • still wrong.
  • Before doing DOM manipulation anywhere in your application, ask yourself if you really need to.
  • a few things wrong with this
  • jQuery was never necessary
  • use angular.element and our component will still work when dropped into a project that doesn't have jQuery.
  • just use angular.element
  • the element that is passed to the link function would already be a jQuery element!
  • directives aren't just collections of jQuery-like functions
  • Directives are actually extensions of HTML
  • If HTML doesn't do something you need it to do, you write a directive to do it for you, and then use it just as if it was part of HTML.
  • think how the team would accomplish it to fit right in with ngClick, ngClass, et al.
  • Don't even use jQuery. Don't even include it.
  • ry to think about how to do it within the confines the AngularJS.
  • In jQuery, selectors are used to find DOM elements and then bind/register event handlers to them.
  • Views are (declarative) HTML that contain AngularJS directives
  • Directives set up the event handlers behind the scenes for us and give us dynamic databinding.
  • Views are tied to models (via scopes). Views are a projection of the model
  • In AngularJS, think about models, rather than jQuery-selected DOM elements that hold your data.
  • AngularJS uses controllers and directives (each of which can have their own controller, and/or compile and linking functions) to remove behavior from the view/structure (HTML). Angular also has services and filters to help separate/organize your application.
  • Think about your models
  • Think about how you want to present your models -- your views.
  • using the necessary directives to get dynamic databinding.
  • Attach a controller to each view (using ng-view and routing, or ng-controller)
  • Make controllers as thin as possible.
  • You can do a lot with jQuery without knowing about how JavaScript prototypal inheritance works.
  • jQuery is a library
  • AngularJS is a beautiful client-side framework
張 旭

Flynn: first preview release | Hacker News - 0 views

news.ycombinator.com/item

docker consul system service discovery dns

shared by 張 旭 on 25 Nov 15 - No Cached
  • Etcd and Zookeeper provide essentially the same functionality. They are both a strongly consistent key/value stores that support notifications to clients of changes. These two projects are limited to service discovery
  • So lets say you had a client application that would talk to a node application that could be on any number of servers. What you could do is hard code that list into your application and randomly select one, in order to "fake" load balancing. However every time a machine went up or down you would have to update that list.
  • What Consul provides is you just tell your app to connect to "mynodeapp.consul" and then consul will give you the proper address of one of your node apps.
  • ...9 more annotations...
  • Consul and Skydock are both applications that build on top of a tool like Zookeeper and Etcd.
  • What a developer ideally wants to do is just push code and not have to worry about what servers are running what, and worry about failover and the like
  • What Flynn provides (if I get it), is a diy Heroku like platform
  • Another project that I believe may be similar to Flynn is Apache Mesos.
  • a self hosted Heroku
  • Google Omega is Google's answer to Apache Mesos
  • Omega would need a service like Raft to understand what services are currently available
  • Raft is a consensus algorithm for keeping a set of distributed state machines in a consistent state.
  • I want to use Docker, but it has no easy way to say "take this file that contains instructions and make everything". You can write Dockerfiles, but you can only use one part of the stack in them, otherwise you run into trouble.
  • 張 旭 on 25 Nov 15
     
    " So lets say you had a client application that would talk to a node application that could be on any number of servers. What you could do is hard code that list into your application and randomly select one, in order to "fake" load balancing. However every time a machine went up or down you would have to update that list. What Consul provides is you just tell your app to connect to "mynodeapp.consul" and then consul will give you the proper address of one of your node apps."
張 旭

Getting Started with Rails - Ruby on Rails Guides - 0 views

guides.rubyonrails.org/getting_started.html

shared by 張 旭 on 22 Jan 14 - Cached
  • A controller's purpose is to receive specific requests for the application.
  • Routing decides which controller receives which requests
  • The view should just display that information
  • ...55 more annotations...
  • view templates are written in a language called ERB (Embedded Ruby) which is converted by the request cycle in Rails before being sent to the user.
  • Each action's purpose is to collect information to provide it to a view.
  • A view's purpose is to display this information in a human readable format.
  • routing file which holds entries in a special DSL (domain-specific language) that tells Rails how to connect incoming requests to controllers and actions.
  • You can create, read, update and destroy items for a resource and these operations are referred to as CRUD operations
  • A controller is simply a class that is defined to inherit from ApplicationController.
  • If not found, then it will attempt to load a template called application/new. It looks for one here because the PostsController inherits from ApplicationController
  • :formats specifies the format of template to be served in response. The default format is :html, and so Rails is looking for an HTML template.
  • :handlers, is telling us what template handlers could be used to render our template.
  • When you call form_for, you pass it an identifying object for this form. In this case, it's the symbol :post. This tells the form_for helper what this form is for.
  • that the action attribute for the form is pointing at /posts/new
  • When a form is submitted, the fields of the form are sent to Rails as parameters.
  • parameters can then be referenced inside the controller actions, typically to perform a particular task
  • params method is the object which represents the parameters (or fields) coming in from the form.
  • Active Record is smart enough to automatically map column names to model attributes,
  • Rails uses rake commands to run migrations, and it's possible to undo a migration after it's been applied to your database
  • every Rails model can be initialized with its respective attributes, which are automatically mapped to the respective database columns.
  • migration creates a method named change which will be called when you run this migration.
  • The action defined in this method is also reversible, which means Rails knows how to reverse the change made by this migration, in case you want to reverse it later
  • Migration filenames include a timestamp to ensure that they're processed in the order that they were created.
  • @post.save returns a boolean indicating whether the model was saved or not.
  • prevents an attacker from setting the model's attributes by manipulating the hash passed to the model.
  • If you want to link to an action in the same controller, you don't need to specify the :controller option, as Rails will use the current controller by default.
  • inherits from ActiveRecord::Base
  • Active Record supplies a great deal of functionality to your Rails models for free, including basic database CRUD (Create, Read, Update, Destroy) operations, data validation, as well as sophisticated search support and the ability to relate multiple models to one another.
  • Rails includes methods to help you validate the data that you send to models
  • Rails can validate a variety of conditions in a model, including the presence or uniqueness of columns, their format, and the existence of associated objects.
  • redirect_to will tell the browser to issue another request.
  • rendering is done within the same request as the form submission
  • Each request for a comment has to keep track of the post to which the comment is attached, thus the initial call to the find method of the Post model to get the post in question.
  • pluralize is a rails helper that takes a number and a string as its arguments. If the number is greater than one, the string will be automatically pluralized.
  • The render method is used so that the @post object is passed back to the new template when it is rendered.
  • The method: :patch option tells Rails that we want this form to be submitted via the PATCH HTTP method which is the HTTP method you're expected to use to update resources according to the REST protocol.
  • it accepts a hash containing the attributes that you want to update.
  • field_with_errors. You can define a css rule to make them standout
  • belongs_to :post, which sets up an Active Record association
  • creates comments as a nested resource within posts
  • call destroy on Active Record objects when you want to delete them from the database.
  • Rails allows you to use the dependent option of an association to achieve this.
  • store all external data as UTF-8
  • you're better off ensuring that all external data is UTF-8
  • use UTF-8 as the internal storage of your database
  • Rails defaults to converting data from your database into UTF-8 at the boundary.
  • :patch
  • By default forms built with the form_for helper are sent via POST
  • The :method and :'data-confirm' options are used as HTML5 attributes so that when the link is clicked, Rails will first show a confirm dialog to the user, and then submit the link with method delete. This is done via the JavaScript file jquery_ujs which is automatically included into your application's layout (app/views/layouts/application.html.erb) when you generated the application.
  • Without this file, the confirmation dialog box wouldn't appear.
  • just defines the partial template we want to render
  • As the render method iterates over the @post.comments collection, it assigns each comment to
  • a local variable named the same as the partial
  • use the authentication system
  • require and permit
  • the method is often made private to make sure it can't be called outside its intended context.
  • standard CRUD actions in each controller in the following order: index, show, new, edit, create, update and destroy.
  • must be placed before any private or protected method in the controller in order to work
張 旭

Active Record Migrations - Ruby on Rails Guides - 0 views

edgeguides.rubyonrails.org/active_record_migrations.html

rails database model migration

shared by 張 旭 on 12 Apr 16 - No Cached
    • 張 旭
      張 旭 on 12 Apr 16
       
       跟 belongs_to 與 has_many 設定對應的 Migrattion
    • 張 旭
      張 旭 on 12 Apr 16
       
      has_and_belongs_to_many 的對應？
  • add_column and remove_column
  • ...114 more annotations...
  • allowing your schema and changes to be database independent.
  • each migration as being a new 'version' of the database
  • each migration modifies it to add or remove tables, columns, or entries
  • Active Record will also update your db/schema.rb file to match the up-to-date structure of your database.
  • A primary key column called id will also be added implicitly, as it's the default primary key for all Active Record models
  • roll this migration back, it will remove the table
  • timestamps macro adds two columns, created_at and updated_at
  • On databases that support transactions with statements that change the schema, migrations are wrapped in a transaction
  • reversible
  • use up and down instead of change
  • Migrations are stored as files in the db/migrate directory, one for each migration class.
  • a UTC timestamp identifying
  • Rails uses this timestamp to determine which migration should be run and in what order
  • "AddXXXToYYY" or "RemoveXXXFromYYY"
  • use a Ruby DSL
  • column type as references
  • part_number:string:index
  • a migration to remove a column
  • "CreateXXX"
  • change_column_null
  • AddUserRefToProducts
  • :references
  • produce join tables if JoinTable is part of the name
  • CreateJoinTable
  • The model and scaffold generators will create migrations appropriate for adding a new model.
  • enclosed by curly braces and follow the field type
  • create_table
  • By default, create_table will create a primary key called id
  • add an index on the new column
  • when using MySQL, the default is ENGINE=InnoDB
  • create_join_table creates an HABTM (has and belongs to many) join table
  • To customize the name of the table, provide a :table_name option:
  • create_join_table also accepts a block
  • change_table, used for changing existing tables
  • remove
  • rename
  • add_column
  • change_column
  • remove_column
  • change_column_default
  • place an SQL fragment in the :options option.
  • limit
  • precision
  • scale
  • polymorphic
  • default
  • index
  • add_foreign_key
  • Active Record only supports single column foreign keys.
  • use the old style of migration using up and down methods instead of the change method.
  • .connection.execute
  • change_table is also reversible, as long as the block does not call change, change_default or remove.
  • remove_column is reversible if you supply the column type as the third argument
  • Complex migrations may require processing that Active Record doesn't know how to reverse
  • reversible
  • Using reversible will ensure that the instructions are executed in the right order too.
  • add_column add_foreign_key add_index add_reference add_timestamps change_column_default (must supply a :from and :to option) change_column_null create_join_table create_table disable_extension drop_join_table drop_table (must supply a block) enable_extension remove_column (must supply a type) remove_foreign_key (must supply a second table) remove_index remove_reference remove_timestamps rename_column rename_index rename_table
  • :column_options option
  • have the option :null set to false by default
  • By default, the name of the join table comes from the union of the first two arguments provided to create_join_table
  • in alphabetical order
  • change_column command is irreversible.
    • 張 旭
      張 旭 on 12 Apr 16
       
      關聯物在前，被關聯物在後。 A 關聯到 B
  • If the column names can not be derived from the table names, you can use the :column and :primary_key options.
  • figure out the column name
  • foreign key for a specific column
  • foreign key by name
    • 張 旭
      張 旭 on 12 Apr 16
       
      不懂 column 跟 name 的用法差異，基本上一樣。
  • Active Record knows how to reverse the migration automatically
    • 張 旭
      張 旭 on 12 Apr 16
       
      使用內建的 method，Rails 比較容易自動 rollback
    • 張 旭
      張 旭 on 12 Apr 16
       
      除了幾個特殊的 change_ 跟 remove_
  • should use reversible or write the up and down methods instead of using the change method
  • If your migration is irreversible, you should raise ActiveRecord::IrreversibleMigration from your down method.
  • DontUseConstraintForZipcodeValidationMigration
  • rails db:migrate
  • the db:migrate task also invokes the db:schema:dump task, which will update your db/schema.rb file to match the structure of your database.
  • specify a target version
  • all migrations up to and including 20080906120000
  • run the down method on all the migrations down to, but not including, 20080906120000
  • rails db:rollback
  • db:migrate:redo task is a shortcut for doing a rollback and then migrating back up again
    • 張 旭
      張 旭 on 12 Apr 16
       
      舊版的還是 rake！
  • STEP parameter
  • db:setup task will create the database, load the schema and initialize it with the seed data
  • db:reset task will drop the database and set it up again. This is functionally equivalent to rails db:drop db:setup.
  • run a specific migration up or down, the db:migrate:up and db:migrate:down
  • the RAILS_ENV environment variable
  • db:migrate VERBOSE=false will suppress all output.
  • If you have already run the migration, then you cannot just edit the migration and run the migration again: Rails thinks it has already run the migration and so will do nothing when you run rails db:migrate.
  • must rollback the migration (for example with bin/rails db:rollback), edit your migration and then run rails db:migrate to run the corrected version.
  • editing existing migrations is not a good idea.
  • should write a new migration that performs the changes you require
  • revert method can be helpful when writing a new migration to undo previous migrations in whole or in part
  • require_relative
  • revert
  • They are not designed to be edited, they just represent the current state of the database.
  • Schema Files for
  • Schema files are also useful if you want a quick look at what attributes an Active Record object has
  • annotate_models gem automatically adds and updates comments at the top of each model summarizing the schema if you desire that functionality.
  • database-independent
  • multiple databases
  • db/schema.rb cannot express database specific items such as triggers, stored procedures or check constraints
  • you can execute custom SQL statements, the schema dumper cannot reconstitute those statements from the database
  • db:structure:dump
    • 張 旭
      張 旭 on 12 Apr 16
       
      資料庫種類不相依的 schema 付出的代價就是有些特殊的資料庫特性無法描述出來，例如 trigger；如果有在 migration 寫 SQL 的，簡單說 schema dumper 這邊就要設定成 :sql 而不是預設的 :ruby
  • set in config/application.rb by the config.active_record.schema_format setting, which may be either :sql or :ruby.
  • check them into source control.
  • db/schema.rb contains the current version number of the database
  • Validations such as validates :foreign_key, uniqueness: true are one way in which models can enforce data integrity
  • The :dependent option on associations allows models to automatically destroy child objects when the parent is destroyed.
  • Migrations can also be used to add or modify data
  • Initial
  • To add initial data after a database is created, Rails has a built-in 'seeds' feature that makes the process quick and easy.
  • db/seeds.rb
  • rails db:seed
張 旭

Active Record Callbacks - Ruby on Rails Guides - 0 views

guides.rubyonrails.org/active_record_callbacks.html

ruby rails model callback

shared by 張 旭 on 12 Apr 16 - No Cached
  • Active Record provides hooks into this object life cycle so that you can control your application and its data.
  • Callbacks allow you to trigger logic before or after an alteration of an object's state.
  • Callbacks are methods that get called at certain moments of an object's life cycle.
  • ...42 more annotations...
  • created
  • saved
  • updated
  • deleted
  • validated
  • loaded
  • use a macro-style class method to register them as callbacks
  • self.name = login.capitalize if name.blank?
  • registered to only fire on certain life cycle events
  • considered good practice to declare callback methods as protected or private
  • all the available Active Record callbacks,
  • after_initialize callback will be called whenever an Active Record object is instantiated, either by directly using new or when a record is loaded from the database
  • after_find callback will be called whenever Active Record loads a record from the database.
  • after_find is called before after_initialize if both are defined
  • after_touch callback will be called whenever an Active Record object is touched.
  • belongs_to :company, touch: true
  • methods trigger callbacks
  • after_find callback is triggered by the following finder methods
  • after_initialize callback is triggered every time a new object of the class is initialized
  • should be used with caution, however, because important business rules and application logic may be kept in callbacks.
  • As you start registering new callbacks for your models, they will be queued for execution
  • The whole callback chain is wrapped in a transaction
  • Callbacks work through model relationships, and can even be defined by them.
  • As with validations, we can also make the calling of a callback method conditional on the satisfaction of a given predicate
  • When using the :if option, the callback won't be executed if the predicate method returns false; when using the :unless option, the callback won't be executed if the predicate method returns true.
  • with a Symbol
  • with a String
  • with a Proc
  • using eval and hence needs to contain valid Ruby code.
  • mix both :if and :unless in the same callback declaration
  • needed to instantiate a new PictureFileCallbacks object, since we declared our callback as an instance method.
  • Active Record makes it possible to create classes that encapsulate the callback methods, so it becomes very easy to reuse them.
  • won't be necessary to instantiate
  • after_commit
  • after_rollback
  • very similar to the after_save callback except that they don't execute until after database changes have either been committed or rolled back
  • delete_picture_file_from_disk
  • after_commit
  • If anything raises an exception after the after_destroy callback is called and the transaction rolls back, the file will have been deleted and the model will be left in an inconsistent state
    • 張 旭
      張 旭 on 12 Apr 16
       
      刪除檔案這種動作，要在資料庫的變動正確執行完成之後。
  • don't supply the :on option the callback will fire for every action.
  • The after_commit and after_rollback callbacks are guaranteed to be called for all models created, updated, or destroyed within a transaction block.
張 旭

Using Workflows to Schedule Jobs - CircleCI - 1 views

circleci.com/workflows

circleci CI deploy system

shared by 張 旭 on 25 Nov 18 - No Cached
  • A workflow is a set of rules for defining a collection of jobs and their run order.
  • Schedule workflows for jobs that should only run periodically.
  • run multiple jobs in parallel
  • ...37 more annotations...
  • rerun just the failed job
  • Builds without workflows require a build job.
  • Refer the YAML Anchors/Aliases documentation for information about how to alias and reuse syntax to keep your .circleci/config.yml file small.
  • workflow orchestration with two parallel jobs
  • jobs run according to configured requirements, each job waiting to start until the required job finishes successfully
  • requires: key
  • fans-out to run a set of acceptance test jobs in parallel, and finally fans-in to run a common deploy job.
  • Holding a Workflow for a Manual Approval
  • Workflows can be configured to wait for manual approval of a job before continuing to the next job
  • add a job to the jobs list with the key type: approval
  • approval is a special job type that is only available to jobs under the workflow key
  • The name of the job to hold is arbitrary - it could be wait or pause, for example, as long as the job has a type: approval key in it.
  • schedule a workflow to run at a certain time for specific branches.
  • The triggers key is only added under your workflows key
  • using cron syntax to represent Coordinated Universal Time (UTC) for specified branches.
  • By default, a workflow is triggered on every git push
  • the commit workflow has no triggers key and will run on every git push
  • The nightly workflow has a triggers key and will run on the specified schedule
  • Cron step syntax (for example, */1, */20) is not supported.
  • use a context to share environment variables
  • use the same shared environment variables when initiated by a user who is part of the organization.
  • CircleCI does not run workflows for tags unless you explicitly specify tag filters.
  • CircleCI branch and tag filters support the Java variant of regex pattern matching.
  • Each workflow has an associated workspace which can be used to transfer files to downstream jobs as the workflow progresses.
  • The workspace is an additive-only store of data.
  • Jobs can persist data to the workspace
  • Downstream jobs can attach the workspace to their container filesystem.
  • Attaching the workspace downloads and unpacks each layer based on the ordering of the upstream jobs in the workflow graph.
  • Workflows that include jobs running on multiple branches may require data to be shared using workspaces
  • To persist data from a job and make it available to other jobs, configure the job to use the persist_to_workspace key.
  • Files and directories named in the paths: property of persist_to_workspace will be uploaded to the workflow’s temporary workspace relative to the directory specified with the root key.
  • Configure a job to get saved data by configuring the attach_workspace key.
  • persist_to_workspace
  • attach_workspace
  • To rerun only a workflow’s failed jobs, click the Workflows icon in the app and select a workflow to see the status of each job, then click the Rerun button and select Rerun from failed.
  • if you do not see your workflows triggering, a configuration error is preventing the workflow from starting.
  • check your Workflows page of the CircleCI app (not the Job page)
  • 張 旭 on 25 Nov 18
     
    "A workflow is a set of rules for defining a collection of jobs and their run order."
張 旭

What Is a Service Mesh? - NGINX - 0 views

www.nginx.com/...what-is-a-service-mesh

docker service networking nginx proxy

shared by 張 旭 on 27 Aug 18 - No Cached
  • The mesh provides service discovery, load balancing, encryption, authentication and authorization, support for the circuit breaker pattern, and other capabilities.
  • The service mesh is usually implemented by providing a proxy instance, called a sidecar, for each service instance
  • the term service is often used for both the instance definitions and the instances themselves.
  • ...5 more annotations...
  • A sidecar proxy is a proxy instance that’s dedicated to a specific service instance.
  • The container management framework keeps a list of instances that are ready to receive requests.
  • The service mesh can encrypt and decrypt requests and responses
  • a service mesh application also includes a monitoring and management layer, called the control plane.
  • Service mesh architectures are not ever likely to be the answer to all application development and delivery problems
張 旭

Caddyfile Tutorial - How to Configure Caddy - 0 views

caddyserver.com/...caddyfile

caddy proxy tutorial

shared by 張 旭 on 12 Sep 18 - No Cached
  • Directives are keywords that Caddy recognizes.
  • Directives might have one or more arguments after them
  • Some directives require more configuration than can fit on one line. For those directives, you can open a block and set more parameters.
  • ...11 more annotations...
  • The first line of the Caddyfile is always the address of the site to serve
  • If the directive block is left empty, you should omit the curly braces entirely.
  • Arguments that contain whitespace must be enclosed in quotes ".
  • To configure multiple sites with a single Caddyfile, you must use curly braces around each one to separate their configurations:
  • he opening curly brace must be at the end of the same line.
  • The closing curly brace must be on its own line.
  • All directives must appear inside a site's definition.
  • Site addresses can also be defined under a specific path or have wildcards in place of individual domain labels from the left side
  • using a path in your site address will route requests by longest matching prefix.
  • Use of environment variables is allowed in addresses and arguments. They must be enclosed in curly braces,
  • you may not specify the same site address more than once
  • 張 旭 on 12 Sep 18
     
    "Directives"
張 旭

The Caddyfile Syntax - 0 views

caddyserver.com/caddyfile

caddy proxy HA

shared by 張 旭 on 12 Sep 18 - No Cached
  • A Caddyfile can be used to configure any Caddy server type: HTTP, DNS, etc.
  • The Caddyfile is plain Unicode text encoded with UTF-8.
  • lowercase and uppercase characters are different.
  • ...17 more annotations...
  • A token that starts with quotes " is read literally (including whitespace) until the next instance of quotes " that is not escaped.
  • Only quotes are escapable.
  • Blank, unquoted lines are allowed and ignored.
  • Tokens are then evaluated by the parser for structure.
  • A Caddyfile has no global scope.
  • A label is a string identifier, and a definition is a body (one or more lines) of tokens grouped together in a block
  • a Caddyfile with more than one entry must enclose each definition in curly braces { }.
  • The first line of a Caddyfile is always a label line.
  • If many labels are to head a block, the labels may be suffixed with a comma.
  • as long as the last label of the line has a comma if the next line is to continue the list of labels
  • Commas are not acceptable delimiters for arguments
  • Arguments are delimited solely by same-line whitespace
  • Subdirectives cannot open new blocks.
  • nested directive blocks are not supported
  • Any token (label, directive, argument, etc.) may contain or consist solely of an environment variable
  • Where an import line is, that line will be replaced with the contents of the imported file, unmodified.
  • define snippets to be reused later in your Caddyfile by defining a block with a single-token label surrounded by parentheses
張 旭

Use multi-stage builds | Docker Documentation - 0 views

docs.docker.com/...multistage-build

docker system

shared by 張 旭 on 29 Sep 18 - No Cached
  • Maintaining two Dockerfiles is not ideal.
  • This is failure-prone and hard to maintain. It’s easy to insert another command and forget to continue the line using the \ character
  • create a container from it to copy the artifact out
  • ...4 more annotations...
  • You only need the single Dockerfile. You don’t need a separate build script,
  • You don’t need to create any intermediate images and you don’t need to extract any artifacts to your local system at all.
  • Debugging a specific build stage
  • You can use the COPY --from instruction to copy from a separate image, either using the local image name, a tag available locally or on a Docker registry, or a tag ID.
張 旭

Deploy services to a swarm | Docker Documentation - 0 views

docs.docker.com/...services

docker swarm system

shared by 張 旭 on 07 Sep 18 - No Cached
  • Swarm services use a declarative model, which means that you define the desired state of the service, and rely upon Docker to maintain this state.
  • To create a single-replica service with no extra configuration, you only need to supply the image name.
  • A service can be in a pending state if its image is unavailable
  • ...12 more annotations...
  • If your image is available on a private registry which requires login, use the --with-registry-auth flag
  • When you update a service, Docker stops its containers and restarts them with the new configuration.
  • When updating an existing service, the flag is --publish-add. There is also a --publish-rm flag to remove a port that was previously published.
  • To update the command an existing service runs, you can use the --args flag.
  • force the service to use a specific version of the image
  • If the manager can’t resolve the tag to a digest, each worker node is responsible for resolving the tag to a digest, and different nodes may use different versions of the image.
  • After you create a service, its image is never updated unless you explicitly run docker service update with the --image flag as described below.
  • When you run service update with the --image flag, the swarm manager queries Docker Hub or your private Docker registry for the digest the tag currently points to and updates the service tasks to use that digest.
  • You can publish a service task’s port directly on the swarm node where that service is running.
  • You can rely on the routing mesh. When you publish a service port, the swarm makes the service accessible at the target port on every node, regardless of whether there is a task for the service running on that node or not.
  • To publish a service’s ports externally to the swarm, use the --publish <PUBLISHED-PORT>:<SERVICE-PORT> flag.
  • published port on every swarm node
張 旭

User Variables - Templates - Packer by HashiCorp - 0 views

www.packer.io/...user-variables.html

packer virtualization image devops

shared by 張 旭 on 12 Apr 19 - No Cached
  • User variables allow your templates to be further configured with variables from the command-line, environment variables, Vault, or files.
  • define it either within the variables section within your template, or using the command-line -var or -var-file flags.
  • If the default value is null, then the user variable will be required.
  • ...7 more annotations...
  • User variables are available globally within the rest of the template.
  • The env function is available only within the default value of a user variable, allowing you to default a user variable to an environment variable.
  • As Packer doesn't run inside a shell, it won't expand ~
  • To set user variables from the command line, the -var flag is used as a parameter to packer build (and some other commands).
  • Variables can also be set from an external JSON file. The -var-file flag reads a file containing a key/value mapping of variables to values and sets those variables.
  • -var-file=
  • sensitive variables won't get printed to the logs by adding them to the "sensitive-variables" list within the Packer template
張 旭

The Twelve-Factor App - 0 views

12factor.net/port-binding

development application programming

shared by 張 旭 on 20 Feb 19 - No Cached
  • The twelve-factor app is completely self-contained
  • using dependency declaration to add a webserver library to the app, such as Tornado for Python, Thin for Ruby, or Jetty for Java and other JVM-based languages.
  • the port-binding approach means that one app can become the backing service for another app
張 旭

Introduction To The Queue System - Diving Laravel - 0 views

divinglaravel.com/troduction-to-the-queue-system

php programming laravel

shared by 張 旭 on 02 Mar 19 - No Cached
  • Laravel is shipped with a built-in queue system that helps you run tasks in the background
  • The QueueManager is registered into the container and it knows how to connect to the different built-in queue drivers
  • for example when we called the Queue::push() method, what happened is that the manager selected the desired queue driver, connected to it, and called the push method on that driver.
  • ...2 more annotations...
  • All calls to methods that don't exist in the QueueManager class will be sent to the loaded driver
  • when you do Queue::push() you're actually calling the push method on the queue driver you're using
  • 張 旭 on 02 Mar 19
     
    "Laravel is shipped with a built-in queue system that helps you run tasks in the background "
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