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CakePHP Migrations plugin: easily version and deploy whole applications

This article is a quick introduction to the Migrations plugin, open sourced a few weeks ago by our company. You will see how simple it is to use the plugin and what you could do with it. I hope this article will show you the benefits of using migrations in your CakePHP applications and make you give it a try right after the reading!

Here is a one-sentence description of the plugin: the Migrations plugin allows developers to easily version and automate the creation / update process of any database schema and application data from the command line.

For information, CakeDC uses this plugin on its project since several years to make team collaboration and deployment easier. The plugin has been entirely rewritten a few months ago and fully tested (code coverage >95% as always at CakeDC) before being open sourced under the MIT license. It is now available to the community along with its documentation... and it is free!

Why is it useful?

It has been a while since companies integrated Source Code Management in their development process and CVS, SVN, Mercurial or Git are now common tools. Inspired from the open source movement it is also a good practice for single developers to version application source code.

As you might know, an application almost always depends of the database schema it is aimed to use... however it is not easy to version both the source code and database schema with a SCM. Let's take the example of a CakePHP application: until now the only way to do was to version a single file, either a sql dump or a CakePHP schema.php file generated with the cake schema shell. These two approaches are not very convenient to use on a daily basis, the first one forcing the developer to drop and recreate the whole database every time!

Moreover, a web application development is never really finished (there are always new features to add, software updates or bug fixing to do...) and deploying these change on a test or production server is always a delicate task.

Here comes the Migrations plugin! It provides a simple and easy way to version a database... and to perform many other different tasks thanks to its callback system. Here are some features:

  • keep a local database schema up-to-date: you just have to run all non applied migrations to update the local database schema to the latest version
  • make team work easier: when several developers work on the same application it is important that all of them work with the same database schema during all the development cycle. With migrations every commit is tied to the database schema at this precise instant, which makes easy switching branches and resetting a branch to a specific commit.
  • make installation and updates easier: ready to push the new version of your application live? You will only have to push the sources on the server and run all non applied migrations!
  • migrate more than database schema: the callback system allows you to do everything you want before (or after) applying (or reverting) each migration. Here are some examples: creating an initial admin account, add initial or test data to the application (lorem ipsums, categories, content...), update values from the database, send an email if debug > 0... The only limit may be your imagination ;)

Where can I find the code?

Announced a few weeks ago, a packaged version of the plugin can be downloaded from the "Plugins" section of CakeDC.com. This page contains a link to download the 1.0 version, the plugin documentation and the Github project for tickets and direct Git access to the repository.

To make people aware of the need to show their support to the Cake Software Fundation by donating a few bucks (this is unfortunately not done enough), the plugin was first available to donors only. The "Download without donation" button was added later, when the repository was made public! However, if you find this plugin useful please consider making a donation to the CSF... that is the best thing you could do for thanking us.

Even better! A sample application was also released for those who want to see how migrations could be used and integrated in an application. To play with it, Download the code or git clone the project using:

git clone git://codaset.com/cakedc/sample-migrations-application.git sample_migrations

You will only need to create a database.php configuration file and update CakePHP's core location to make the application work. Git users, run

git submodule init
git submodule update

to automatically add the migrations plugin as a submodule!

What do I need to use it in my application?

Note: the packaged plugin is for the CakePHP 1.3 version only. You can either download the 1.3-beta package of the framework, or use the 1.2 branch available in the Git repository.

Adding the plugin to an existing application is very simple. If you downloaded the archive containing the plugin code, unzip it in the "/plugins/migrations" folder of your application. Git users can add it as a submodule with the following command:

git submodule add git://codaset.com/cakedc/migrations.git plugins/migrations

To check that it is installed correctly, execute the following command from your application root (it will display the available command to use the plugin):

cake migration help

If you encounter any problem here, please read the official documentation about CakePHP's console usage.

How does it work?

This post is not aimed at providing a comprehensive tutorial on how to use the plugin, thus I will just introduce the most useful commands along with some use cases.

For a complete documentation, please read the official documentation provided on the plugin page. For a simple (but useful for understanding purpose) use case you can take a look at the sample application introduced above. Going through the commit history will allow you to understand how migrations could be used in a development process.

Create a migration

To generate a new migration, type the following command

cake migration generate

The tool will ask you to give a name to the migration and suggest to do a dump of the current database schema. If a "schema.php" file is found in the application, it will ask you if you want to generate a diff between this schema and your current database one.

Generated migration files will be added to the "/config/migrations" application directory.

Apply / Revert migrations

When you pull an application containing migrations, several commands are available to apply or revert migrations. The simplest one is:

cake migration

It will display all the found migrations along with their status (applied or not applied) and id number. Just enter a migration number to update your database to the correct version. Some convenience commands are also available. You can use:

cake migration up, down, all or reset

These commands will respectively:

  • apply the next migration
  • revert the latest applied migration
  • apply all non applied migrations (and thus update the schema to the most recent version)
  • revert all applied migrations (and empty the database)

Migrations for plugins

Adding plugins to an existing application often implies adding new tables to the database or altering existing ones. The Migrations plugin brings a quick and efficient way to automate this installation. On the one hand developers can easily add necessary migrations to their plugin (making upgrades easier), on the other hand users can apply them as easily.

The only difference compared with commands introduced above is the parameter "-plugin pluginname" that needs to be added. Here is how the user will install the database for the newly added / updated plugin "test":

cake migration run all -plugin test

I would like to highlight the fact that callbacks allow the developer to do everything they want before / after each migration. It is convenient for adding initial data, and one can even implement a callback method opening the bootstrap.php file to append plugin's configuration entries there (it is just an example ;)).

... going further

Of course, feel free to add any remark or example of migrations use in the comments.

As this post is not aimed at providing support for the plugin, I recommend you to use the official tools available:

  • If you found a bug or want to suggest enhancements: open a ticket!
  • An installation problem or a question about the plugin usage? Ask your question to the community!
  • You would like a custom version of this plugin, or professional related services... contact us, it is our job ;)

I hope you enjoyed this post, it is now time for you to start playing with the Migrations plugin...

Latest articles

How to push Docker image to Container Registry and create App on...

The title speaks for itself, let’s jump right in! As a preliminary step, we start from a user registered in DigitalOcean with a validated account. Use the doctl tool for the entire communication process with DigitalOcean.

Step 1: Install doctl

$ cd ~
$ wget https://github.com/digitalocean/doctl/releases/download/v1.71.0/doctl-1.71.0-linux-amd64.tar.gz
$ tar xvf doctl-1.71.0-linux-amd64.tar.gz
$ sudo mv doctl /usr/local/bin
 

Step 2: Create an API token

  Go to https://cloud.digitalocean.com/account/api/tokens Generate new token for read and write and save apart the value of token generated <TOKEN NAME>: personaltoken 
<TOKEN VALUE>: 6e981fc2a674dbb7a610b9b85d0c8b00

Step 3: Use the API token to grant account access to doctl

$ doctl auth init --context personaltoken
Validating token... OK
Prompt for <TOKEN VALUE>, then enter it and press return 
 

Step 4: Validate that doctl is working

$ doctl auth init  Validating token... OK
  Prompt for <TOKEN VALUE>, then enter it and press return  Validate by obtaining the account information
$ doctl account get Email      Droplet Limit    Email Verified    UUID         Status email@cakedc.com    10     true     5415bbf8-d501-4096-9b75-ab781c017948    active
 

Step 5: Create a Container Registry with doctl

<MY-REGISTRY-NAME> : container-nyc-795 <REGION> : nyc3
$ doctl registry create container-nyc-795 --region nyc3 Name       Endpoint        Region slug container-nyc-795    registry.digitalocean.com/container-nyc-795    nyc3

Important: the region of the Container registry and Kubernetes cluster MUST be the same Keep in mind that container names must be unique, must be lowercase, and only accepts alphanumeric characters and hyphens.  

Step 6: Login to authenticate docker with your registry

$ doctl registry login
Logging Docker in to registry.digitalocean.com
 

Step 7: Create kubernetes cluster

$ doctl kubernetes cluster create cluster-static-example --region nyc3 Notice: Cluster is provisioning, waiting for cluster to be running ................................................................... Notice: Cluster created, fetching credentials Notice: Adding cluster credentials to kubeconfig file found in "/home/andres/.kube/config" Notice: Setting current-context to do-nyc3-cluster-static-example ID                                      Name                      Region    Version        Auto Upgrade    Status     Node Pools d24f180b-6007-4dbc-a2fe-3952801570aa    cluster-static-example    nyc3      1.22.7-do.0    false           running    cluster-static-example-default-pool
Important: the region of the Container registry and Kubernetes cluster MUST be the same here as well.  This operation isn’t a fast process.  

Step 8: Integrate kubernetes cluster in Container register

$ doctl kubernetes cluster registry add cluster-static-example
 

Step 9: Get token certificate and connect to cluster

$ doctl kubernetes cluster kubeconfig save cluster-static-example Notice: Adding cluster credentials to kubeconfig file found in "/home/andres/.kube/config" Notice: Setting current-context to do-nyc3-cluster-static-example
To validate this, use the kubectl tool to get context. If is not installed, get the last version you find - for example in googleapis
$ wget https://storage.googleapis.com/kubernetes-release/release/v1.23.5/bin/linux/amd64/kubectl
$ chmod +x kubectl
$ sudo mv kubectl /usr/local/bin/
Check with
$ kubectl config current-context
do-nyc3-cluster-static-example
Here, you see: bash prompt do-ny3-cluster-sttic-example. That is the context you created in Step 7
 

Step 10: Generate docker image, tag and push to DigitalOcean

We assume that the user already has docker installed
$ mkdir myapp
$ mkdir myapp/html
$ nano myapp/Dockerfile
  Inside Dockerfile put   
FROM nginx:latest
COPY ./html/hello.html /usr/share/nginx/html/hello.htm
l
  We create simple Dockerfile with NGINX Server and copy the file hello.html in the default html of nginx  
$ nano myapp/html/hello.html
  Inside hello.html put  
<!DOCTYPE html> <html>  <head>    <title>Hello World!</title>  </head>  <body>    <p>This is an example of a simple HTML page served from the Nginx container.</p>  </body> </html>
Then build a docker image file tag with repository and push with docker
 
$ cd myapp
$ docker build -t registry.digitalocean.com/container-nyc-795/static-app .
Sending build context to Docker daemon  3.584kB Step 1/2 : FROM nginx:latest latest: Pulling from library/nginx c229119241af: Pull complete 2215908dc0a2: Pull complete 08c3cb2073f1: Pull complete 18f38162c0ce: Pull complete 10e2168f148a: Pull complete c4ffe9532b5f: Pull complete Digest: sha256:2275af0f20d71b293916f1958f8497f987b8d8fd8113df54635f2a5915002bf1 Status: Downloaded newer image for nginx:latest  ---> 12766a6745ee Step 2/2 : COPY ./html/hello.html /usr/share/nginx/html/hello.html  ---> 2b9be913c377 Successfully built 2b9be913c377 Successfully tagged registry.digitalocean.com/container-nyc-795/static-app:latest   $ docker images REPOSITORY                                               TAG       IMAGE ID       CREATED         SIZE registry.digitalocean.com/container-nyc-795/static-app   latest    2b9be913c377   2 minutes ago   142MB   $ docker push registry.digitalocean.com/container-nyc-795/static-app Using default tag: latest The push refers to repository [registry.digitalocean.com/container-nyc-795/static-app] ac03ae036a53: Pushed ea4bc0cd4a93: Pushed fac199a5a1a5: Pushed 5c77d760e1f4: Pushed 33cf1b723f65: Pushed ea207a4854e7: Pushed 608f3a074261: Pushed latest: digest: sha256:22615ad4c324ca5dc13fe2c3e1d2d801bd166165e3809f96ed6a96a2b2ca2748 size: 1777


Step 11: Create app

Create file example-static-app.yaml and insert: alerts:                                 
- rule: DEPLOYMENT_FAILED               
- rule: DOMAIN_FAILED                   
name: example-static-app                
region: nyc                             
services:                               
- http_port: 80                         
  image:                                
    registry_type: DOCR                 
    repository: static-app              
    tag: latest                         
  instance_count: 2                     
  instance_size_slug: professional-xs   
  name: static-service                  
  routes:                               
  - path: /                             
  source_dir: /             
              Validate file with
$  doctl apps spec validate example-static-app.yaml
Create app
$ doctl apps create --spec example-static-app.yaml
Notice: App created
ID        Spec Name             Default Ingress    Active Deployment ID    In Progress Deployment ID    Created At     Updated At
55a7cb68-65b7-4ff1-b6af-388cdb1df507    example-static-app   2022-03-30 09:34:01.288257225 +0000 UTC    2022-03-30 09:34:01.288257225 +0000 UTC
If you access https://cloud.digitalocean.com/apps And in the live url + /hello.html you can see:

Step 12: Deploy app

If you modify the code of your app, you need to generate a new image with docker and push  (see step 10). Then you don’t need to create a new app, you need to deploy the image in the already created app, with the id executing the command to deploy in bash.
$  doctl apps create-deployment 55a7cb68-65b7-4ff1-b6af-388cdb1df507

 

How to generate deploy of Docker image to Container Registry on DigitalOcean Platform Apps

Once you have created the application (and if you have the code in gitlab), you can create a direct deployment of your code in the DigitalOcean container and deploy on top of your application.

Step 1: Define variables

First two variables are defined in gitlab. You can find these inside project in the left menu - enter in Settings > CI/CD > Variables $DIGITALOCEAN_API_KEY = token generated in DigitalOcean dashboard $APP_ID = previously generated application identifier   More can be defined as the name of the repository. The value of these variables will be injected into the file that we will create below in the Step 3  

 

Step 2: Register runner in gitlab

In your project in the left menu, go to Settings > CI/CD > Runners Create a specific runner for the project in the URL with registration token. Register GitLab Runner from the command line. It is important to use docker and privileged
# Download the binary for your system
sudo curl -L --output /usr/local/bin/gitlab-runner https://gitlab-runner-downloads.s3.amazonaws.com/latest/binaries/gitlab-runner-linux-amd64

# Give it permission to execute
sudo chmod +x /usr/local/bin/gitlab-runner

# Register runner
sudo gitlab-runner register -n --url https://git.cakedc.com --registration-token GR1348941gx7sgV3pZFQgRqg5qUR_ --executor docker --description "My Docker Runner" --docker-image "docker:19.03.12" --docker-privileged --docker-volumes "/certs/client"
 

Step 3: Create file gitlab-ci.yml 

The gitlab-ci.yml file takes care of

  • Authentication and identification using doctl in DigitalOcean
  • Generating and sending the docker image to the DigitalOcean container
  • Deploying the container image to an existing app
Create the file gitlab-ci.yml in the root of your project as
image: docker:20-dind

variables:
  DOCKER_HOST: tcp://docker:2375
  DOCKER_DRIVER: overlay2
  DOCKER_TLS_CERTDIR: ""
  REPOSITORY_URL: registry.digitalocean.com/container-nyc-795/static-app
  CONTAINER_NAME: static-app

services:
  - name: docker:20-dind
    alias: docker
    command: ["--tls=false"]

before_script:
  - apk update
  - apk upgrade
  - apk add doctl --repository=http://dl-cdn.alpinelinux.org/alpine/edge/community
  - docker info

build:
  stage: build
  script:
    - doctl auth init --access-token $DIGITALOCEAN_API_KEY
    - doctl account get     
    - echo $DIGITALOCEAN_API_KEY | docker login -u $DIGITALOCEAN_API_KEY --password-stdin registry.digitalocean.com
    - docker build -t $REPOSITORY_URL:latest .
    - docker push $REPOSITORY_URL
    - doctl apps create-deployment $APP_ID
Now, every time you do a git push in your project, the runner will automatically inject the variables defined previously in the gitlab-ci.yml file. Then, it will generate a docker image with docker (docker-in-docker) to create an image of your project, send it to the digitalocean repository and deploy it in the app configured.   That’s it!  

CakeFest 2021 Recap

Here we are again coming off of the CakeFest sugar high! I don’t even know where to begin.    Unfortunately, or fortunately - I haven’t decided, we had to do another virtual event. The safety of speakers, staff and attendees is very important to us, so a physical event was not the best option in our opinion with traveling.    However, after this event, I started thinking about the people who were able to attend from the comfort of their own homes or offices. These people may not have been able to travel or attend otherwise, and that gives me our silver lining. Not to mention that we had more ticket sales this year than any of our previous events (at least that I can remember).    The theme, for me anyway, ha ha, was traveling the world, ironically. We started in the Canary Islands, traveled to Germany, to Canada, to England and Austria. We had new faces from the US, the Czech Republic and even Japan - and more! This is, as I’ve mentioned, one of the best things about the CakePHP community, we have community members all over the world. This was our chance to come together.    So let’s get to the event. Here’s what you may have missed: 

Workshops:

Workshop 1 Jorge González (Twitter: @steinkelz) Topics covered included: 0:00 - Docker development environment for CakePHP 15:56 - Middlewares  30:05 - Security 1:31:36 - Performance optimization 2:04:49 - Events   Workshop 2 Michael Hoffmann (Twitter: @cleptric) Topics covered included: 0:00:00 -Setup login action in CakePHP 0:29:10 - Vite with hot reloading Vue.js tailwind css   Workshop 3 Mark Story (Twitter: @mark_story) Topics covered included: 0:04:25 - Leveraging new style fixtures 0:48:26 - Using the DI container 1:30:13 - Browser automation testing with Panther. 2:17:13 - Helpers you may need.
 

Talks:

* Juan Pablo Ramirez (Twitter: @jpramidev) gave the keynote talk on behalf of Passbolt. * Sho Ito (Twitter: @itosho) taught us all about Components * Yuki Kanazawa (Twitter: @yakitori009) and this talk about Automatically Distributing Reference Queries to    Read Replica in CakePHP4 * Mark Scherer (Twitter: @dereuromark) schooled attendees on IDE in CakePHP development * Jiri Havlicek (Twitter: @Jerryhavl) played a big role in fighting COVID-19 by helping create a  contact tracing app (developed with CakePHP) in Czech Republic * Chris Miller (Twitter: @ccmiller2019) explained standards and why we use them * Kevin Phifer (Twitter: @lordsimal)  joined in to explain how to re-use code - utility classes and PHP namespaces * Paul Henriks created a plugin with attendees LIVE * Ed Barnard (Twitter: @ewbarnard) brought the dragons! He talked about finding the Joy in Software Development * Chris Hartjes (Twitter: @grmpyprogrammer) delivered a Grumpy Programmer's Guide to being a senior developer  * Joe Ferguson (Twitter: @joepferguson) shared his knowledge on Modern Infrastructure as code with Ansible * Timo Stark (Twitter: @linux_lenny) shared details about NGINX Unit - and how to modernize your CakePHP deployments

Trivia and giveaways 

Cake ceremony dedicated to Mark Story

We took this time to thank and acknowledge Mark Story for all of his hard work and dedication that he puts into CakePHP. He then headed the cake cutting ceremony (virtually of course) as speakers and attendees enjoyed their own treats!   See the full archive here: https://cakefest.org/archive/virtual-2021  

So what’s to come? 

First!  Videos are starting to be released. With the help of community member Aroop Roelofs, we will be releasing these videos faster than expected. Ticket holders have been receiving access, and they will be released publicly in the coming days.  In regards to future events, it’s up in the air. We will have some internal discussions about safety measures and restrictions, then we will weigh the option between another virtual or physical event. We will, of course, reach out to the community for their input.  I will close by just saying THANK YOU. Thank you for making my job worth it. When an event runs smoothly and gets so much great feedback, that is a direct reflection from the community support. We hope you all will continue to join us in years to come!    Thanks for baking!  

Dependency Injection with CakePHP

Let’s talk about Dependency Injection!

SOLID principles

As you know SOLID is an acronym for the  five object-oriented design principles. In this topic, we will focus on Interface segregation principle and Dependency inversion principle. Interface segregation principle states that a client must not be forced to implement an interface that they do not use, or clients shouldn’t be forced to depend on methods they do not use. In other words, having  many client-specific interfaces is better than one general-purpose interface. From the other side, Dependency inversion principle states that objects must depend on abstractions, not on concretions. It states that the high-level module must not depend on the low-level module, but they should depend on abstractions. To follow Dependency inversion principle, we need to construct low-level modules and pass them to constructors, and that might create a lot of manual work for developers. The dependency injection container is created specifically for solving the problem with manual construction of an object, before creating a specific object. If we follow interface segregation principle when developing application modules, it would be easy to configure a container and switch module dependency. This is where the interface shows its incredible power.  

Few words about CakePHP Events System

CakePHP Events System was created to allow injecting some logic using listeners. However, in some cases, it is used to get results from code that will be created by the module user. When an event is dispatched by the listener, it can return the result. Callback injection through the event system has some drawbacks. First of all, parameters passed to the event need to pass as a hash array. So unfortunately, there is no way to check that all params are really passed or to be sure that all passed params have correct types. Is there a way to solve this problem? Yes, and containers could help with that. Instead of passing events, we can get the required object from the container and call it method. But you could say: wait, we don't know what object could be used in client code within the developed plugin. That's fine, and this  is where interface segregation principle can help. In our plugin, we define an interface for each such case, and instead of dispatching an event, we can easily get an object from the container by interface.       $updater = $container->get(AfterLoginInterface::class);     if ($updater !== null) {         $user = $updater->afterLogin($user);     }   In the Application::services method, users link the interface with the specific class.       public function services(ContainerInterface $container): void     {         $container->add(AfterLoginInterface::class, MyAfterLogin::class);     }   In some of default behavior needed we can map service class for container to default implementation using Plugin::services method.       public function services(ContainerInterface $container): void     {         if (!$container->has(AfterLoginInterface::class)) {             $container->add(AfterLoginInterface::class, NullAfterLogin::class);         }     }  

Container propagation

Dependency injection is an experimental feature. Initial implementation limited by Controllers constructors and methods, and Commands constructors. If we want to access the container in other parts of the application, we may want to propagate it from app level. The most logical way would be to implement middleware and store the container inside the request attribute.   <?php declare(strict_types=1);   namespace App\Middleware;   use Cake\Core\ContainerInterface; use Psr\Http\Message\ResponseInterface; use Psr\Http\Message\ServerRequestInterface; use Psr\Http\Server\MiddlewareInterface; use Psr\Http\Server\RequestHandlerInterface; use RuntimeException;   /**  * Container Injector Middleware  */ class ContainerInjectorMiddleware implements MiddlewareInterface {     /**      * @var \Cake\Core\ContainerInterface      */     protected $container;       /**      * Constructor      *      * @param \Cake\Core\ContainerInterface $container The container to build controllers with.      */     public function __construct(ContainerInterface $container)     {         $this->container = $container;     }       /**      * Serve assets if the path matches one.      *      * @param \Psr\Http\Message\ServerRequestInterface $request The request.      * @param \Psr\Http\Server\RequestHandlerInterface $handler The request handler.      * @return \Psr\Http\Message\ResponseInterface A response.      */     public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface     {         return $handler->handle($request->withAttribute('container', $this->container));     }   That’s it! I hope that this will help you when you are baking with dependency injections. If you run into any problems, there are many support channels that allow the CakePHP community to help  You can check them out under the community tab at CakePHP.org.

We Bake with CakePHP