CakeDC Blog

TIPS, INSIGHTS AND THE LATEST FROM THE EXPERTS BEHIND CAKEPHP

How to push Docker image to Container Registry and create App on DigitalOcean Platform Apps

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!

 

Latest articles

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.

One CakePHP Project Per Day

The whole team here at CakeDC are big supporters and contributors of the CakePHP community. For this month, I decided to do “one CakePHP project per day” to share with the community.  Here are some of my projects so far:

Project 01 - Notes App

A one page note application using CakePHP 4 and Bootstrap 5. This project is  a good starting point to learn the framework. Link: https://github.com/rochamarcelo/one-project-a-day-challenge-01-notes  

Project 02 - Contact List

An application to manage contacts - you are able to list, add, edit and delete contacts, upload contact avatar images or use avatar images from gravatar.com . It was built using CakePHP 4, plugin friendsofcake/search, plugin josegonzalez/cakephp-upload, Gravatar, and Bootstrap 5.  Link: https://github.com/rochamarcelo/one-project-a-day-challenge-02-contact-list  

Project 03 - Recipe Box

An application to manage recipes, using CakePHP 4,  CouchDB and Bootstrap 5. This one is a good starting point to learn to use CouchDB with CakePHP, including how to list, add and edit recipes (documents). Link: https://github.com/rochamarcelo/one-cakephp-project-a-day-challenge-03-recipe-box  

Project 04 - Service Plan with Exchange rate

An application to list services and apply exchange rate using the api https://exchangeratesapi.io/documentation/ and CakePHP 4. In this one you see the custom namespace WebService to handle logic related to api as client. Link: https://github.com/rochamarcelo/one-cakephp-project-a-day-challenge-04-service-plans-ex-rate  

Project 05 - Polls

A fun poll app, using the awesome Bulma CSS Framework and CakePHP 4. A good example of model association and the CounterCache Behavior. Link: https://github.com/rochamarcelo/one-cakephp-project-a-day-challenge-05-polls-emmy  

Project 06 - Movie Theater Schedule

An application to see which movies are in the theaters and which hours by screen each day of the week. A good example of complex queries, model associations and seed data. Link: https://github.com/rochamarcelo/one-cakephp-project-a-day-challenge-06-movie-theater-schedule  

Project 07 - Podcast Finder

An application to help easily find podcasts and download episodes. In the source code you’ll find how to use the itunes api,  a structure to handle Model actions (that I think is a good option to make your models cleaner), and a way to parse podcasts feed (XML); example usage of dependency injection. The application was built with CakePHP 4 and Bulma CSS Framework. Link: https://github.com/rochamarcelo/one-cakephp-project-a-day-challenge-07-podcast-finder  

Project 08 - Url Shortener

An application to create short urls - a good example of how to create custom routes and use custom primary key types for a model. The application was built with CakePHP 4. Link: https://github.com/rochamarcelo/one-cakephp-project-a-day-challenge-08-url-shortener  

Project 09 - Quiz

Users can list quizzes, create quizzes and answer at any time. A good example of how to use MongoDB with CakePHP 4 with a base structure for Collection classes.  Link: https://github.com/rochamarcelo/one-cakephp-project-a-day-challenge-09-quiz  

Project 10 - File Transfer

An application to easily send files to anyone, create an account, upload the file and inform the person email to send to. Built with CakePHP 4, plugin CakeDC/Users,  plugin Josegonzalez/Upload,  plugin friendsofcake/bootstrap-ui, SMTP and Bootstrap. A good example to see the usage of these plugins. Link: https://github.com/rochamarcelo/one-cakephp-project-a-day-challenge-10-file-transfer  

Project 11 - Tasks

A one page application for  users to manage their tasks. The user can create and remove decks, create and complete tasks, and list tasks grouped by decks. Built with CakePHP 4, plugin CakeDC/Users and Bootstrap 5 Link: https://github.com/rochamarcelo/one-cakephp-project-a-day-challenge-11-tasks  

Project 12 - Blog

A blog website with blog posts and tags management, WYSIWYG editor, blog search, tags filtering. Built with CakePHP 4, CakeDC/Users plugin, friendsofcake/bootstrap-ui, Muffin/Slug, friendsofcake/search and Bootstrap 4 . A good example of usage of custom routes, route prefix, finders and multiple plugins. Link: https://github.com/rochamarcelo/one-cakephp-project-a-day-challenge-12-blog  

Project 13 - Olympic Medal Count

Perfect time for this project, right?! An application to display olympic medal count by country and sports. The source code uses CouterCache behavior and aggregated query. Built with CakePHP 4 and Bootstrap 5. Link: https://github.com/rochamarcelo/one-cakephp-project-a-day-challenge-13-olympic-medal-count
 

Project 14 - Smart Home Dashboard

An awesome dashboard to manage smart devices using MQTT Messaging, CakePHP 4, CakeDC/Users plugin, php-mqtt/client (testing with Mosquitto Broker) and Bootstrap 5. The application is able to publish messages to change device status and subscribe for status changes. Link: https://github.com/rochamarcelo/one-cakephp-project-a-day-challenge-14-smart-home-dashboard-mqtt    I hope that this initiative will somehow inspire others to put their Cake skills to work, and share their projects with the community. If you’d like to see my future projects and posts, you can follow me on Twitter, and I will share them all there! https://twitter.com/mrcodex

We Bake with CakePHP